MedCosmos Surgery

Paradoxical Aciduria

2008-09-07T16:07:00.000-07:00

Patients with gastric outlet obstruction represent the classic clinical scenario for metabolic alkalosis in which a deficiency of chloride and potassium in ECF is also present. Parietal cells in the stomach mucosa produce gastric fluid that has a high hydrochloric acid concentration. For each proton pumped into gastric fluid, bicarbonate is added to ECF by the parietal cell. Patients who lose large amounts of gastric fluid deplete their ECF of protons and chloride, as well as potassium. Renal function plays a key role in hypochloremic, hypokalemic metabolic alkalosis. In these alkalemic patients urine pH can be lower than 7. Such patients paradoxically produce an acid urine despite having alkalemia because of three phenomena.

1.These patients have lost large amounts of ECF, and consequently the renin-angiotensin-aldosterone hormonal axis is activated. As aldosterone levels increase, patients have an accelerated exchange of tubule sodium for potassium and protons in the DCT of the nephron.

2.A second phenomenon contributing to the paradoxical production of an acidic urine in a patient with alkalemia is depletion of chloride, which has the renal consequence that with less chloride available in the proximal segments of the nephron, there is less capacity to reabsorb sodium with chloride and consequently delivery of sodium ions to the DCT is increased.

3.Finally, loss of potassium in gastric fluid contributes to the paradoxical production of acidic urine in these patients because with less potassium available in the tubule cells of the DCT, the capacity to exchange potassium for a sodium molecule in the tubule fluid is impaired. In the circumstance of hypokalemia, the tubule cells are driven by aldosterone to make greater use of protons as the exchange cation for the sodium transported out of the tubule fluid.

Surgeons correct the alkalemia of hypochloremic, hypokalemic metabolic alkalosis by IV infusions of electrolyte-containing solutions. Isotonic saline fluids are given to expand the ECF to normal. Supplemental KCl is administered to restore the potassium concentration to normal. One indication that a patient has been fully resuscitated is that the urine pH becomes appropriately alkaline. Rarely, patients with severe alkalemia need to be given a carbonic anhydrase inhibitor drug to reduce the renal tubule cell's capacity to generate protons for transport to urine. Surgeons cure patients with hyperchloremic, hypokalemic metabolic alkalemia by performing a surgical procedure that eliminates the foregut obstruction. For example, surgeons cure patients with gastric outlet obstruction caused by duodenal ulcer disease and alkalemia related to vomiting by performing a pyloroplasty.

Thoracic Surgery MCQ

2008-09-06T19:11:00.000-07:00

1. The bronchial circulation:
A. Is the blood supply to the conducting airways.
B. Drains into a peribronchial venous network that may expand considerably with conditions such as bronchiectasis and chronic obstructive pulmonary disease.
C. Is an especially important consideration in pulmonary transplantation.
D. All of the above.
Answer: D

DISCUSSION: The bronchial circulation is the primary blood supply for the conducting airways, pulmonary vessels, lymphoid tissue, and squamous cell carcinomas. In conditions such as mitral stenosis, bronchiectasis, or chronic obstructive pulmonary disease, the rich peribronchial venous network that drains the bronchial circulation may expand considerably, creating significant left-to-right shunts. Whenever the pulmonary artery circulation is obstructed, there is a tendency for bronchial circulation to increase; thus, the bronchial circulation is an important consideration during lung transplantation as well as in the surgical treatment of cyanotic congenital heart disease and chronic pulmonary embolism.

2. Clearance of mucus produced in the tracheobronchial tree in chronic bronchitis secondary to smoking may:
A. Be hampered by the fact that the amount of mucus is increased by the number of mucus-producing cells at the expense of ciliated cells.
B. Be slowed if patients have decreased lung volume and are therefore unable to generate a vigorous cough that would cause an inflammatory process.
C. Cause a decrease in diffusion capacity and associated hypoxemia.
D. All of the above.
Answer: A

DISCUSSION: Chronic bronchitis may have an acute component, and in these patients therapy with antibiotics and bronchodilators may improve the flow rate as measured by pulmonary function tests within 3 or 4 days of the cessation of smoking and treatment of the acute condition. However, the chronic bronchitic will continue to produce large amounts of mucus, most evident in the morning, even after the acute process has been resolved. Clearance of these secretions is hampered by the inability to cough, perhaps secondary to the pain of thoracotomy or abdominal surgery or by a decrease in the number of ciliary cells that help move mucus up the tracheobronchial tree. This causes plugging of small airways and atelectasis, which may progress to pneumonia. For this reason, cessation of smoking for 3 to 5 days before surgery is very beneficial in preventing pulmonary complications during the postoperative period.

3. The pulmonary circulation:
A. Is the only vascular system in which the veins do not have the same course as the arteries.
B. Has a direct connection of vein to adjacent lung tissue by connective tissue fibers, making the diameter of the tissue fibers dependent upon lung volume.
C. Supplies the metabolic needs of the alveoli.
D. All of the above.
Answer: C

DISCUSSION: Pulmonary artery circulation transports oxygenated blood to the alveoli level where gas exchange occurs, and it is here that the matching of ventilation and perfusion is so important during the postoperative period. The loss of lung volume that generally occurs after all surgical procedures does not return to baseline for 5 to 7 days and may play an important role in the ventilation-perfusion ratio. Improving or returning lung volume to normal is performed by manipulating functional residual capacity (FRC) and preventing atelectasis, which in turn maintains circulation to the alveolus and optimizes the ventilation-perfusion ratio.

4. Which of the following screening tests are important for preoperative evaluation of pulmonary function?
A. History and physical examination.
B. Room air arterial blood gases.
C. Chest film.
D. Vital capacity and forced expiratory volume in 1 second (FEV 1).
E. Cardiopulmonary exercise testing.
Answer: ABCDE

DISCUSSION: The most important clues to impairment of respiratory function are found in the history and physical examination. A negative history and physical examination in combination with a relatively normal room air arterial blood gas and normal chest film are sufficient to screen patients to support the clinical impression that there is minimal pulmonary disease. Patients with symptoms, positive physical findings, and/or abnormalities in the arterial blood gases or chest film can be screened most effectively with an additional evaluation of the vital capacity and FEV 1. More elaborate tests such as cardiopulmonary exercise testing are reserved for patients with obvious and marked impairment of pulmonary function who are being evaluated for the feasibility of surgical intervention.

5. Carbon monoxide diffusion capacity (DLCO) has been shown to correlate with:
A. The thickness of the alveolar lining membrane.
B. The permeability of the erythrocyte to carbon dioxide.
C. Pulmonary emboli.
D. Total alveolar-capillary capacity.
Answer: ABCD

DISCUSSION: The single-breath DLCO is a screening test that has been shown to be decreased in all of the above examples. It is an estimate of the total capacity of the functional alveolar microarchitecture and has been demonstrated to be an independent measure of physiologic capability apart from the FEV 1 and forced ventilatory capacity.

6. The closing volume is:
A. The volume remaining in the lung at the end of expiration below which alveolar collapse begins to occur, resulting in physiologic shunting.
B. Higher in young persons.
C. Not changed during surgery.
D. Relative to the oxygen content of mixed venous blood.
Answer: AC

DISCUSSION: The closing volume is conceptually the remaining lung volume at the end of expiration below which alveolar collapse begins to occur, causing intrapulmonary right-to-left shunting and thus desaturation of blood in the left atrium. In a normal young person this closing volume is well below the functional residual capacity (FRC); thus, such physiologic shunting does not occur until there is a decrease in the elastic properties of the lung. Although FRC gradually increases with age, so does the effective closing volume. Eventually some alveoli are being underventilated (at end-expiration), allowing physiologic right-to-left shunting to occur. Closing volume is unchanged, but FRC decreases during surgery (i.e., shunting occurs). Closing volume has no direct relationship to the oxygen content of the mixed venous blood.

7. The effect of high positive end-expiratory pressures (PEEP) on cardiac output is:
A. None.
B. Increased cardiac output.
C. Decreased cardiac output because of increased afterload to the left ventricle.
D. Decreased cardiac output because of decreased effective preload to the left ventricle.
Answer: D

DISCUSSION: Higher levels of PEEP can be associated with decreases in cardiac output as a consequence of an effective decrease in the preload to the left ventricle owing to impaired left ventricular filling.

8. Weaning patients from maximum ventilator support usually involves:
A. Weaning PEEP first, tidal volume second, and the fraction of inspired oxygen (FIO 2) third.
B. Weaning FIO 2 first, ventilator rate second, and PEEP third.
C. Weaning FIO2 first, PEEP second, and tidal volume third.
D. Weaning FIO 2 first, PEEP second, and ventilator rate third.
Answer: D

DISCUSSION: When the inspired oxygen concentration is greater than 60% for more than 24 to 28 hours, the risk of oxygen toxicity increases. PEEP is usually weaned to physiologic levels (i.e., 5 to 7 cm. H 2O) before weaning either rate or tidal volumes. Generally, the optimal tidal volume to achieve alveolar recruitment is selected and usually is not decreased unless peak airway pressures increase. If decreases in ventilatory rate are not tolerated, airway pressure support can be added.

9. Which of the following statements about bronchoscopy is false?
A. The morbidity and mortality are approximately 0.2% and 0.08%, respectively.
B. The most common complications of bronchoscopy are related to premedication of patients.
C. Adjunctive cancer therapy such as laser treatment and brachytherapy may be administered via this route.
D. A chronic cough and unilateral wheezing are accepted indications for bronchoscopy.
E. Early postoperative bronchoscopy for atelectasis is contraindicated following pulmonary resection.
Answer: E

DISCUSSION: The stated complication rates are true and reported from a comprehensive review of over 24,000 patients. Although the most common complications are related to the premedication, significant hemorrhage, pneumothorax, bronchospasm, and dysrhythmias have been reported. In addition to laser and brachytherapy, phototherapy and immunotherapy have been given by bronchoscopy. Unilateral wheezing may represent a bronchial foreign body, and a chronic cough could signify myriad pulmonary disorders. Accordingly, both are amenable to diagnostic bronchoscopy. Most thoracic surgeons favor early bronchoscopy for lobar atelectasis following pulmonary surgery.

10. Flexible bronchoscopy is preferred over rigid bronchoscopy for all of the following except:
A. Patients with cervical spine injuries requiring intubation.
B. The evaluation of a smoke inhalation injury.
C. Transcarinal needle aspiration of an enlarged subcarinal lymph node.
D. The removal of a bronchus intermedius foreign body from an infant.
E. A cost-effective evaluation of mild hemoptysis.
Answer: D

DISCUSSION: Neither patients with significant cervical spine disease or injuries nor those with large aortic arch aneurysms should undergo rigid bronchoscopy, given the greater risk of complications. Even if severe, smoke inhalation injury can be assessed adequately by flexible bronchoscopy. Transbronchial needle aspiration of lesions that on computed tomography (CT) look suspicious is safe and quite easily performed with fluoroscopic guidance. Hemoptysis as a presenting symptom should be evaluated by flexible bronchoscopy. In contrast, for massive hemoptysis an airway should be secured for ventilation with a rigid bronchoscope. Similarly, an airway needs to be maintained while removing endobronchial foreign bodies from infants or children. Since adequate port sites for instrumentation are also needed, the rigid bronchoscope is preferred in this setting.

11. Which of the following approaches is/are currently acceptable for the management of spontaneous pneumothorax?
A. Chest tube replacement alone for the patient with a first episode.
B. Operation on presentation for any patient with a first episode.
C. Video-assisted thoracic surgery (VATS) bleb excision and pleurodesis for recurrent pneumothorax on the same side.
D. Thoracotomy with bleb excision and pleurodesis for unilateral recurrent pneumothorax.
E. Operation after a first episode in an airline pilot.
Answer: ACDE

DISCUSSION: Primary spontaneous pneumothorax typically occurs in young patients with congenital blebs at the apices of the lungs. Rupture of these blebs causes pneumothorax, which recurs in about 30% of patients. Standard care on initial presentation is chest tube placement alone. Operation traditionally has been performed during the initial episode only if there is prolonged air leakage (longer than 7 days); in patients with bilateral pneumothorax; those who live in an area where prompt medical care, if needed, is not available; and those frequently exposed to extremes of pressure (e.g., airline pilots). Both VATS and thoracotomy approaches to excision of blebs and pleurodesis have been shown to be effective. The availability of the apparently safer VATS approach has led some to favor earlier operation.

12. For which patient(s) with a pulmonary infiltrate of uncertain cause would you favor VATS over open wedge excision?
A. An AIDS patient with a diffuse infiltrate who is ambulatory but requires supplemental oxygen. Bronchoalveolar lavage is negative.
B. A 64-year-old previously healthy man with increasing shortness of breath, a diffuse infiltrate, and restrictive lung disease as shown by pulmonary function studies.
C. A 74-year-old diabetic woman with a rapidly progressing process throughout the right lung who is ventilator- and pressor-dependent.
D. A 44-year-old man with fever, left-sided infiltrate, and shortness of breath.
E. A 79-year-old man on a ventilator for right lower and middle lobe pneumonia which has been culture negative.
Answer: ABD

DISCUSSION: Lung biopsy by VATS or minithoracotomy is often indicated in the work-up of a pulmonary infiltrate that has not been successfully diagnosed by less invasive studies. This procedure probably is not indicated for cancer patients with acute pneumonitis, as broad-spectrum antibiotics frequently are successful treatments. For those who do require the procedure, the choice between VATS and thoracotomy is determined by the severity of illness. In those who are critically ill and ventilator dependent, changing the tube to an endobronchial tube for thoracoscopy may be risky, and in these cases an anterior thoracotomy with single-lumen ventilation is indicated. These patients, who are frequently heavily sedated and are likely to remain so for some time postoperatively, are unlikely to benefit from the greatest advantage of VATS, the reduction of postoperative pain. It is, then, the ambulatory patient with a chronic interstitial process who benefits the most from the VATS approach.

13. Which of the following statements about the cause and prevention of postintubation tracheal stenosis are correct?
A. Postintubation airway stenosis can largely be avoided by providing assisted ventilation via endotracheal tube rather than tracheostomy tube.
B. Postintubation tracheal stenosis at the cuff level results, more or less equally, from low blood pressure, advanced age, steroids, high intracuff pressure, sensitivity to tube materials, gas sterilization elution products, and systemic disease.
C. In women and smaller men large endotracheal tubes can produce lesions of the glottis and subglottis that can progress to stenosis.
D. Stomal stenosis is due principally to cicatricial closure of large stomas resulting from removal of a disk or segment of tracheal wall during tracheostomy.
E. A large-volume tracheostomy tube cuff such as that now used on most available tubes can become a high-pressure cuff if filled beyond its resting maximal volume.
Answer: CE

DISCUSSION: Use of an endotracheal tube, of course, avoids a stoma and related complications. Cuff lesions, however, are incurred from cuffs on endotracheal tubes, cricothyroidostomy tubes, and tracheostomy tubes. A cuff is the common factor. Endotracheal tubes, on the other hand, cause erosion at the level of the glottis and subglottis, in particular. Although many factors may play some role in the origin of airway stenosis, the principal factor is pressure necrosis of the mucosa, submucosa, and ultimately of the cartilage, with subsequent cicatrization. Large endotracheal tubes do, indeed, cause necrosis and airway injury at narrow areas in the upper airway, at glottic and cricoid levels. Such injuries lead to posterior commissure stenosis, arytenoid fixation, vocal cord erosion and granulomas, anterior commissure stricture, and subglottic circumferential stenosis. While excision of a large amount of tracheal wall can lead inevitably to healing by contraction with narrowing of the tracheal circumference, the most usual cause of stomal stenosis is erosion of the stoma by pressure from the tracheostomy tube. This in turn may relate to leverage by equipment. Additional factors appear to be subsidiary. A large volume, low pressure tracheostomy tube cuff, such as those currently available, if properly constructed, will seal the trachea before it is necessary to stretch the cuff by adding an increasing volume of air. If the cuff is stretched beyond that resting volume, which usually occludes the normal trachea, high pressures will develop because the plastic material from which all of these cuffs are now made is not very extensible. Therefore, the pressure-volume curve rises sharply once the limit of unstretched volume is passed. A low-pressure cuff then becomes a high-pressure cuff.

14. Which of the following statements about the treatment of postintubation airway stenosis are correct?
A. Emergency management of airway obstruction due to stenosis at the level of a prior tracheal stoma is best accomplished by establishing a new tracheostomy in normal tracheal tissue just below the scar of the old stoma.
B. Radial lasering and dilatation usually leads to permanent resolution of postintubation tracheal stenosis.
C. Splinting of a cervical trachea with a silicone T-tube for 6 to 8 months generally leads to permanent resolution of stricture.
D. Postintubation tracheal stenosis that extends into the subglottic larynx is treated by resection of a cylindrical sleeve of stenotic airway and end-to-end reconstruction.
E. Acquired tracheoesophageal fistula due to intubation injury is corrected by surgical closure of the fistula concurrent with resection and reconstruction of the damaged trachea.
Answer: E

DISCUSSION: Emergency management of postintubation tracheal stenosis is accomplished by dilatation under general anesthesia using rigid bronchoscopes and dilators. Tracheostomy is employed only when the patient requires a prolonged or a permanent airway before or instead of resection and reconstruction. If a new tracheostomy is needed it is preferable to place it through the area of existing stenosis—in this case the site of prior tracheostomy—rather than to injure normal trachea that will be needed for resection and reconstruction. If the stenosis is below the sternal notch, a long tracheostomy tube is inserted at the usual position (second and third rings) but extends past the now dilated stenotic lesion.
Lasering almost never results in a permanently satisfactory airway; the exception is the very limited lesion described as a thin, weblike stenosis. Such lesions are rare. Unfortunately, laser is widely used and often compounds existing damage by concurrent placement of a tracheostomy tube below the lesion in the normal trachea. T-tubes are very useful for temporizing when repair is not possible or must be delayed. It almost never leads to resolution of a stricture unless it is an extremely limited one. Soon after removal of the T-tube the stricture reasserts itself.
If the lesion involves the subglottic larynx, complex repair is required to preserve the recurrent laryngeal nerve's anatomy and function. The posterior cricoid plate is salvaged and resurfaced with a flap of membranous tracheal wall; the anterior subglottic larynx is reconstructed with a “prow” of distal tracheal cartilage and mucosa.
A tracheoesophageal fistula is managed (after weaning from a respirator) by layered closure of the esophagus, interposition of a flap of well-vascularized tissue (such as a pedicled strap muscle), and resection and reconstruction of the damaged trachea. Since the fistula results from the pressure of a cuff, often against an esophageal feeding tube, there is circumferential damage to the trachea at the level of the fistula. Resection and reconstruction are therefore necessary, in addition to closure of the fistula, for successful treatment of this complex lesion.

15. Which of the following statements are true?
A. Pyogenic lung abscess occurs most frequently in the lower lobe of the left lung.
B. Anaerobic bacteria are commonly present in pyogenic lung abscess.
C. Operation is usually required to eradicate a pyogenic lung abscess.
D. Penicillin is the treatment of choice for lung abscess.
Answer: BD

DISCUSSION: Pyogenic lung abscess is the result of aspiration of debris from the oropharynx. Since most patients are unconscious and supine when this occurs, the aspirated material usually finds its way into the most dependent bronchi. These are the superior division of the right lower lobe and the posterior segment of the right upper lobe. The organisms most commonly responsible for pyogenic lung abscess are the same anaerobic bacteria found in the mouths of patients with poor oral hygiene. In addition to anaerobic organisms alpha- and beta-hemolytic streptococci, staphylococci, nonhemolytic streptococci, and Escherichia coli may be present. Gram-negative rods and staphylococci are particularly common in hospital-acquired infections. These organisms are almost always penicillin sensitive. Surgical therapy is rarely necessary to eradicate a pyogenic lung abscess. Penicillin, alone or in combination with metronidazole, is the drug of choice. Metronidazole alone probably lacks sufficient activity against anaerobic and microaerophilic streptococci. Clindamycin is also effective against most anaerobic bacteria present in pyogenic lung abscesses.

16. Amphotericin B is effective for the following lung infections:
A. Histoplasmosis.
B. North American blastomycosis.
C. Aspergillosis.
D. Mucormycosis.
E. Sporotrichosis.
Answer: ABD

DISCUSSION: Amphotericin B is effective against most fungal infections, including histoplasmosis and North American blastomycosis. Aspergillosis is caused by the fungus Aspergillus fumigatus, an organism that is resistant to treatment with iodides, nystatin, hydroxystilbamidine, and amphotericin B. The treatment for this fungal infection is a surgical procedure, if the patient's condition permits. Surgical excision and amphotericin B usually are necessary to treat mucormycosis. Itraconazole is the drug of choice for sporotrichosis. Itraconazole, ketoconazole, and fluconazole should be considered as primary or secondary drugs when treating systemic fungal infections.

17. The following statements are true.
A. A distinguishing roentgenographic appearance of lung abscess, the air-fluid level can be seen only on roentgenograms obtained in the upright or lateral decubitus position.
B. The fungus ball characteristic of aspergillosis can be seen roentgenographically in either the upright or recumbent position.
C. Actinomycosis and nocardiosis are both fungal diseases of the lung that respond to treatment with the newer azole antifungal agents.
D. The commonest fungal lung infection in the United States is due to Histoplasma capsulatum.
Answer: ABD

DISCUSSION: An air-fluid level distinguishes a lung abscess. While this can be seen easily in an upright or lateral decubitus roentgenogram, it cannot be seen when the patient is recumbent. The fungus ball characteristic of aspergillosis is identified by its crescent-shaped shadow on a roentgenogram. When the patient changes from an upright to recumbent position, the fungus ball may also change position in the cavity in the lung. Both actinomycosis and nocardiosis are bacterial infections and do not respond to antimycotic treatment. Actinomyces israelli is treated with penicillin and Nocardia asteroides is sensitive to trimethoprim-sulfamethoxazole. The most common fungal infection in North America is histoplasmosis. More than 30 million people have been infected, most of whom are asymptomatic.

18. Pneumocystis pneumonia is an opportunistic infection caused by Pneumocystis carinii. Which of the following statements are true?
A. P. carinii is a fungus.
B. Pneumocystis pneumonia is the most common opportunistic infection in patients with AIDS.
C. The diagnosis of Pneumocystis pneumonia depends on the demonstration of P. carinii organisms in lung tissue.
D. There is no effective treatment for Pneumocystis pneumonia.
Answer: BC

DISCUSSION: P. carinii is a protozoan that stains with silver methenamine and resembles a fungus. It responds to antiprotozoal drugs. Pneumocystis pneumonia occurs in 80% of AIDS patients. The diagnosis is made by demonstrating the organisms in lung tissue by transbronchoscopic lung or brush biopsy, percutaneous needle biopsy, or open lung biopsy. Both trimethoprin-sulfamethoxazole and pentamidine isethionate are effective against P. carinii.

19. Which of the following statements are true?
A. The pleural space does not extend into the neck.
B. Positive intrapleural pressures as high as 40 cm. H 2O and negative pressures as low as -40 cm. H 2O are possible.
C. The pleural cavities cannot absorb more than 500 ml. of fluid per day.
D. All pleural effusions are of clinical significance and should be investigated.
Answer: BD

DISCUSSION: The pleural spaces extend into the neck as well as retrosternally and into the costophrenic sinuses. This should be kept in mind when performing procedures such as subclavian and jugular puncture, to avoid pneumothorax. Markedly elevated intrapleural pressures are obtained with the Valsalva maneuver, and extreme negative pressures can be produced with forced inspiratory effort against a closed glottis. Because of the many microvilli present on the mesothelial cells that line the pleural cavity, a liter or more of fluid is easily secreted or absorbed within a 24-hour period. Most pleural effusions are caused by infection, tumor, or congestive heart failure and should be investigated to determine the proper course of management.

20. Which of the following statements are true?
A. Chylothorax, or chyle in the pleural cavity, usually is not a serious condition.
B. Chyle is easily identified by its milky appearance, which looks like no other kind of pleural effusion.
C. The commonest causes of chylothorax are trauma and tumor.
D. The thoracic duct can be ligated with impunity.
Answer: CD

DISCUSSION: Chylothorax is most often the result of trauma; however, spontaneous chylothorax is also a manifestation of tumor and should be investigated to identify occult malignancies. Chyle in the thorax is characteristically milky white but can be mistaken for the pseudochylothorax of rheumatoid disease or tuberculosis. If necessary, a diagnosis can be confirmed by lymphangiography. This also facilitates ligation of the thoracic duct, should this become necessary to control the loss of chyle.

21. Which of these statements about pleural tumors is/are true?
A. The commonest type of pleural tumor is primary pleural mesothelioma.
B. Exposure to asbestos dust is causally related to the development of malignant mesothelioma.
C. Localized benign mesotheliomas are asymptomatic.
D. Complete pleurectomy for malignant mesothelioma usually results in cure.
Answer: B

DISCUSSION: Pleural involvement by metastatic disease is much more common than primary pleural tumors. Patients with localized benign pleural mesotheliomas may have symptoms of arthralgia, clubbing of the fingers, or fever, which usually disappear after excisional surgery. The evidence relating industrial exposure to asbestosis and malignant pleural mesothelioma is quite strong. Excisional surgery for malignant mesothelioma is usually only palliative. Most patients succumb within 1 to 2 years of the diagnosis, regardless of the kind of treatment they receive.

22. Which of the following correctly describe a patient with spontaneous pneumothorax?
A. The patient is almost always elderly and debilitated.
B. An unsuspected primary or metastatic lung tumor may be present.
C. The administration of supplemental oxygen is of little benefit to the patient.
D. The patient should always be treated with an intercostal tube and closed pleural drainage.
E. Video-assisted thoracic surgery (VATS) should be considered for persistent air leak in patients with secondary spontaneous pneumothorax.
Answer: BE

DISCUSSION: A patient with spontaneous pneumothorax may be old and debilitated, but the typical patient is an otherwise healthy young adult, usually one who smokes. An incidental, unsuspected lung cancer is discovered on rare occasions when operation is performed to control a persistent air leak. Perhaps smoking is a common factor. Absorption of air from the pleural space can be facilitated by the administration of supplemental oxygen. Increasing the oxygen tension lowers the partial pressure of nitrogen (P N2) of the capillary blood and increases the partial pressure difference between the pleural space and the pulmonary capillary. If the pneumothorax results in less than 20% collapse of the lung an asymptomatic patient can be safely observed; however, a larger or persistent pneumothorax is best treated with an intercostal tube thoracostomy. Patients with bullous emphysema may require stapling of bullae and pleurectomy, which can be done by open thoracotomy or thoracoscopically (VATS).

23. Which of the following statements about spontaneous pneumothorax (PSP) is/are correct?
A. The risk of recurrence after resolution of the first episode of PSP or secondary spontaneous pneumothorax (SSP) is 35% to 45%.
B. Patients with PSP are typically tall, thin, young adult males with a history of smoking.
C. Secondary spontaneous pneumothorax is associated with family history in 10% of cases.
D. For bleb resection and pleurodesis thoracoscopic thoracotomy and open thoracotomy provide similar cure rates for patients with primary spontaneous pneumothorax.
E. Causes of secondary pneumothorax include trauma and iatrogenic needle puncture.
Answer: ABD

DISCUSSION: Patients with PSP are usually 20- to 40-year-old males with a common long-chested body habitus. The majority of PSP patients have a history of tobacco use and 10% have a family history of PSP. The majority of cases of SSP are due to advanced emphysema in a population of patients aged 50 to 70 years. Additional causes of SSP include tuberculosis, cystic fibrosis, P. carinii infection, lung cancer, and lung abscess. For patients with PSP bleb resection and pleurodesis performed thoracoscopically provides cure rates similar to those of open thoracotomy. Because of the nature of underlying pulmonary diseases, open thoracotomy appears to provide better results for patients with SSP.

24. Which of the following are relative contraindications for surgical management of emphysema?
A. Rapidly progressive dyspnea.
B. Bullae occupying less than one third of a hemithorax on plain chest radiography.
C. Elevated room air PCO 2.
D. “Pink puffer” patients.
E. FEV 1 less than 35% of predicted value.
Answer: BCE

DISCUSSION: Relative contraindications to operation for bullous emphysema include patients with carbon dioxide retention, FEV 1 less than 35% of predicted value, small bullae that occupy less than one third of a hemithorax, and “blue bloaters,” who are prone to the sequelae of chronic bronchitis. Patients who have primarily emphysema (“pink puffers”) and rapidly progressive dyspnea are usually good candidates for operation.

25. Which of the following treatments would be appropriate therapy for symptoms that persist on medical therapy and bronchiectasis involving, in order of decreasing severity, the left lower lobe, the right middle lobe, and the left upper lobe?
A. Left pneumonectomy.
B. Wedge resection of the left lower lobe.
C. Left lower lobectomy.
D. Simultaneous left lower lobectomy and right middle lobectomy.
Answer: C

DISCUSSION: Pneumonectomy is seldom indicated today for bronchiectasis. Anatomic resection of involved segments with either segmentectomy or lobectomy is preferred to nonanatomic wedge resection. Bilateral pulmonary resections should generally be done as staged procedures, the most symptomatic side being resected first. Then, the contralateral side is resected only if symptoms persist during a prolonged course of medical therapy.

26. Which of the following would not be acceptable sequences of preoperative studies in a patient being prepared for lingulectomy for bronchiectasis?
A. CT alone.
B. CT, bronchoscopy, bronchography.
C. Bronchoscopy alone.
D. Bronchoscopy, bronchography.
Answer: C

DISCUSSION: Bronchoscopy alone is generally not diagnostic for bronchiectasis. Thin-section, high-resolution CT can diagnose bronchiectasis and define the airway anatomy sufficiently for resection. Bronchography is performed less frequently today but can be very useful in diagnosing bronchiectasis and defining airway anatomy for pulmonary resection.

27. Which of the following statements about pulmonary mycobacterial infection is/are correct?
A. Worldwide, tuberculosis no longer represents a significant public health problem.
B. Mycobacterium tuberculosis is responsible for the majority of cases of pulmonary mycobacterial disease.
C. Mycobacterium kansasii pulmonary infection almost always requires surgical treatment.
D. Atypical mycobacteria are never primary pulmonary pathogens in humans.
E. Mycobacterium avium-intracellulare is generally resistant to most antimycobacterial drugs in vitro.
Answer: BE

DISCUSSION: Tuberculosis remains the leading infectious killer in the world today. M. tuberculosis is responsible for the vast majority of pulmonary mycobacterial disease. M. kansasii infection responds to multiple drug chemotherapy and relatively infrequently requires surgical treatment. Atypical mycobacteria can be primary pulmonary pathogens in humans. M. avium-intracellulare is usually resistant in vitro to most antituberculosis drugs.

28. Which of the following chemotherapeutic regimens are currently recommended for the treatment of pulmonary infection caused by M. tuberculosis?
A. Isoniazid, rifampin, pyrazinamide, and streptomycin for 24 months.
B. Isoniazid for 9 months with ethambutol for the first 3 months.
C. Isoniazid and rifampin for 6 months with pyrazinamide added for the first two months.
D. Isoniazid alternating with rifampin at 3-month intervals for 12 months.
E. Isoniazid and rifampin for 9 months.
Answer: CE

DISCUSSION: Treatment of tuberculosis with a single drug leads to rapid emergence of drug-resistant organisms. Any treatment regimen that employs only one drug for a period of time encourages the development of drug-resistant tuberculosis. Currently, the American Thoracic Society recommends either (1) a 6-month regimen consisting of isoniazid, rifampin, and pyrazinamide for 2 months followed by isoniazid and rifampin for 4 months or, alternatively, (2) a 9-month course of isoniazid and rifampin. Prolonged courses of treatment beyond 9 to 12 months no longer are considered necessary.

29. Which of the following are appropriate indications for pulmonary resection for mycobacterial disease?
A. Localized pulmonary disease caused by M. avium-intracellulare.
B. Advanced lobar tuberculous pneumonia with massive hilar lymphadenopathy and bronchial obstruction in a young child.
C. Localized pulmonary disease due to multiple drug–resistant M. tuberculosis.
D. An asymptomatic tuberculous cavity greater than 12 cm. in diameter.
E. Massive hemoptysis from a right upper lobe cavity occurring during an appropriate course of chemotherapy for pulmonary tuberculosis in a sputum-negative patient.
Answer: ACE

DISCUSSION: Modern antimycobacterial chemotherapy is very effective. Surgical treatment of pulmonary mycobacterial disease is rarely necessary; however, pulmonary disease caused by M. avium-intracellulare or multiple drug–resistant M. tuberculosis is not likely to respond to chemotherapy and should be resected if the disease is localized. Chemotherapy for tuberculosis is almost invariably curative in children, regardless of the extent of disease. The size of a tuberculous cavity is not an indication for resection. Massive hemoptysis from a cavitary lesion is life threatening and is an indication for pulmonary resection.

30. Which statements about squamous papillomatosis of the trachea is/are correct?
A. It is the most common type of benign tracheal tumor in adults.
B. It is the most common type of benign tracheal tumor in children.
C. Most are treated with segmental tracheal resection.
D. There is no risk of malignant degeneration.
E. It is associated with a herpesvirus.
Answer: A

DISCUSSION: Squamous papillomatosis is the most common benign tracheal and bronchial tumor in adults. Up to 50% of untreated lesions may degenerate into squamous cell carcinoma. The lesion is associated with human papillomavirus types 6 and 11, and therefore, interferon therapy is under investigation. Most patients can be treated successfully by repeated bronchoscopic fulguration, laser ablation, or cryotherapy.

31. Which of the following statements about pulmonary hamartomas is/are true?
A. Hamartomas are benign chondromas.
B. Most are located in the conducting airways.
C. Wedge resection is curative.
D. A lobectomy is necessary to obtain draining hilar lymph nodes.
E. Hemoptysis is common.
Answer: C

DISCUSSION: Pulmonary hamartomas are benign masses consisting of cartilage, lymph tissue, fat, and epithelial elements. Eighty per cent are located in the lung periphery and are treated by a small wedge resection, usually with a thoracoscope. Most are asymptomatic, and there is no risk of malignant degeneration.

32. Which of the following statements about typical carcinoid tumors are true?
A. They make up the majority of bronchial adenomas.
B. They frequently have lymph node metastases.
C. The carcinoid syndrome is observed in 33%.
D. Overall survival at 5 years is 90%.
E. Overall survival at 5 years is 50%.
Answer: AD

DISCUSSION: Eighty-five per cent of bronchial adenomas are carcinoid tumors. Typical carcinoid tumors have few mitotic figures and infrequent lymph node metastases (fewer than 10%). Only 10% to 15% of patients present with the carcinoid syndrome (flushing, wheezing, diarrhea). Survival after resection is more than 90% at 5 years but decreases to approximately 50% for atypical histology.

33. Which is/are true of adenoid cystic carcinoma?
A. It is a common type of salivary gland tumor.
B. Another name is cylindroma.
C. Most patients are completely resected for cure.
D. Different histological types have different prognoses.
E. Tissue invasion is rare.
Answer: ABCD

DISCUSSION: Adenoid cystic carcinomas (cylindromas) are commonly observed salivary gland tumors that can occur in the conducting airways. The undifferentiated solid type is associated with distant metastases, of which the cribriform and tubular types are associated with perineural and submucosal invasion. Most patients (60%) can be resected for cure.

34. A solitary pulmonary nodule is discovered in an asymptomatic 55-year-old smoker with no evidence of extrathoracic dissemination. The most appropriate management would be to:
A. Obtain serial chest films every 3 months to determine the growth potential of the nodule.
B. Perform transthoracic needle aspiration (TTNA) before considering pulmonary resection to confirm malignancy.
C. Conduct an extensive systematic evaluation to exclude the possibility that the nodule represents a metastatic lesion.
D. Proceed with pulmonary resection after ascertaining that the patient would tolerate removal of the requisite amount of lung.
E. Obtain baseline serum levels of carcinoembryonic antigen and p53.
Answer: D

DISCUSSION: A patient with a solitary pulmonary nodule—a single spherical lesion within the lung— represents an important and challenging diagnostic problem in thoracic oncology. A solitary pulmonary nodule is assumed to be primary lung cancer until proved otherwise; the differential diagnosis includes metastatic carcinoma, granuloma, and benign pulmonary tumors. In most cases, solitary pulmonary nodules should be resected after thorough investigation to establish that systemic dissemination has not already occurred. CT of the chest, liver, and adrenals is performed to confirm the location of the tumor, to evaluate the mediastinum, and to assess the abdomen for systemic disease. If there is no evidence of metastases on CT, the patient should undergo bronchoscopy, which may establish the histologic diagnosis and determine resectability if an endobronchial lesion exists.
Pulmonary function studies are obtained preoperatively to assess the potential for pulmonary resection. A thorough review of systems is undertaken to rule out medical contraindications to thoracotomy. TTNA is not performed routinely and should be reserved for patients with marginal pulmonary function, for whom thoracotomy would be performed only after verification of a malignant histologic diagnosis.

35. After thoracotomy, pulmonary resection, and mediastinal lymph node dissection, a patient is determined to have a squamous cell carcinoma 2 cm. in diameter, located 1 cm. from the carina along the right mainstem bronchus. Three peribronchial lymph nodes are positive for cancer, and all other lymph node stations are negative. The correct stage, according to the TNM system, is:
A. T1N0M0 Stage I.
B. T1N1M0 Stage II.
C. T2N1M0 Stage II.
D. T3N1M0 Stage IIIa.
E. T2N3M0 Stage IIIb.
Answer: C

DISCUSSION: The TNM staging system for carcinoma of the lung provides a consistent, reproducible description of the anatomic extent of disease at the time of diagnosis. In the TNM system, T represents the primary tumor and numerical suffixes describe increasing size or involvement; N represents regional lymph nodes with suffixes to describe levels of involvement; and M designates the presence or absence of distant metastases.
TUMOR (T)
TX Occult carcinoma (malignant cells in sputum or bronchial washings but tumor not visualized by imaging studies or bronchoscopy)
T1 Tumor 3 cm. or less in greatest diameter, surrounded by lung or visceral pleura, but not proximal to a lobar bronchus
T2 Tumor larger than 3 cm. in diameter, or with involvement of main bronchus at least 2 cm. distal to carina, or with visceral pleural invasion, or with associated atelectasis or obstructive pneumonitis extending to the hilar region but not involving the entire lung
T3 Tumor invading chest wall, diaphragm, mediastinal pleura, or parietal pericardium; or tumor in main bronchus within 2 cm. of, but not invading, carina; or atelectasis of obstructive pneumonitis of the entire lung
T4 Tumor invading mediastinum, heart, great vessels, trachea, esophagus, vertebral body, or carina; or ipsilateral malignant pleural effusion
NODES (N)
N0 No regional lymph node metastases
N1 Metastases to ipsilateral peribronchial or hilar nodes
N2 Metastases to ipsilateral mediastinal or subcarinal nodes
N3 Metastases to contralateral mediastinal or hilar, or to any scalene or supraclavicular nodes
DISTANT METASTASES (M)
M0 No distant metastases
M1 Distant metastases
The TNM subsets are subsequently grouped in a series of stages of disease to identify groups of patients with similar prognosis and therapy.

STAGE T N M
Occult TX N0 M0
Stage I T1-2 N0 M0
Stage II T1-2 N1 M0
Stage IIIa T3 N0-1 M0
T1-3 N2 M0
Stage IIIb T4 N0-2 M0
T1-4 N3 M0
Stage IV Any T Any N M1

36. After complete resection of Stage I non-small cell lung cancer (NSCLC), the role of adjuvant therapy is best summarized thus as:
A. Postoperative radiation therapy improves disease-free survival.
B. Postoperative radiation therapy improves overall survival.
C. Postoperative chemotherapy improves disease-free survival.
D. Postoperative chemotherapy improves overall survival.
E. Adjuvant therapy is not indicated after complete resection of Stage I NSCLC.
Answer: E

DISCUSSION: Prospective randomized trials conducted by the Lung Cancer Study Group demonstrate that postoperative chemotherapy may be responsible for significantly longer disease-free survival in patients with Stage III (and perhaps Stage II) NSCLC. The efficacy of postoperative chemotherapy and radiotherapy in patients with extensive lymph node involvement or positive surgical margins in reducing systemic recurrences and prolonging disease-free survival has also been demonstrated. Adjuvant therapy is not associated with improved overall survival and has not been shown to be beneficial in patients with Stage I NSCLC.
Radiation therapy is an effective adjuvant treatment in many patients with carcinoma of the lung. Adjuvant radiotherapy, applied to patients with completely resected Stage II or Stage III (but not Stage I) NSCLC, has been shown to decrease local recurrence but has no significant effect on survival. However, postoperative irradiation may provide a survival advantage in patients who have resection and are found to have metastases to hilar or mediastinal lymph nodes. Thus, the purpose of adjuvant radiotherapy is prevention of local tumor recurrence, especially when lymph node sampling of the mediastinum at thoracotomy is incomplete.

37. Compared to segmentectomy or wedge resection, lobectomy for NSCLC is associated with:
A. Similar operative morbidity but higher operative mortality.
B. Similar operative mortality but higher operative morbidity.
C. More severe postoperative pulmonary dysfunction.
D. Lower incidence of locoregional recurrence.
E. Equivalent locoregional recurrence.
Answer: D

DISCUSSION: The risk of recurrence after surgical resection according to the magnitude of the resection has been analyzed by the Lung Cancer Study Group. In a prospective, randomized trial involving more than 400 patients with T1N0 lung cancer, lobectomy was compared to segmentectomy and wedge resection. There was no significant difference in morbidity and mortality among the procedures. Furthermore, no difference was observed in postoperative pulmonary function between patients who underwent lobectomy and those who underwent lesser procedures. The rate of locoregional recurrence was significantly lower in patients who underwent lobectomy (5%) as compared with those who underwent either segmentectomy or wedge resection (15%). In another study, segmentectomy was compared to lobectomy in patients with Stage I lung cancer. In this study, the rate of locoregional recurrence was lower in patients who underwent lobectomy (5%), as compared with those who underwent segmentectomy (23%). Furthermore, there was a survival advantage in the patients undergoing lobectomy for T2 disease.

38. In contrast to NSCLC, small cell lung cancer (SCLC) is characterized by:
A. Greater response rate to chemotherapy.
B. Inability to achieve surgical cure.
C. Less frequent association with paraneoplastic syndromes at the time of diagnosis.
D. Lower likelihood of metastases present at the time of diagnosis.
E. Slower growth.
Answer: A

DISCUSSION: For the purposes of staging, estimating prognosis, and selecting therapy, lung cancer is divided into two categories: NSCLC and SCLC. SCLC is characterized by more rapid growth, higher prevalence of metastases at the time of diagnosis, and greater responsiveness to chemotherapy and radiation therapy. After ascertaining the histological diagnosis of SCLC, staging is performed, including thorough neurological examination and CT evaluation of the chest, abdomen, and brain. For most patients with limited-stage disease, treatment is initiated with six cycles of combination chemotherapy. Radiotherapy to the chest is usually employed after three initial cycles of chemotherapy and is continued for 4 weeks. Among patients with limited-stage disease, thoracotomy for pulmonary resection is recommended for the subset of patients with stage I SCLC.

39. Which of the following statements about the diagnosis and staging of mesothelioma is/are correct?
A. Fluid obtained by thoracentesis is usually adequate for accurate diagnosis.
B. Open biopsy or thoracoscopy should be performed to obtain tissue for diagnosis.
C. Immunohistochemistry should be performed in all cases of suspected mesothelioma.
D. Chest CT and/or magnetic resonance imaging (MRI) are useful in the staging of mesothelioma.
E. Head CT and bone scans are useful in the staging of mesothelioma.
Answer: BCD

DISCUSSION: Approximately 90% of patients with mesothelioma develop pleural effusion, but cytologic specimens from pleural fluid are inaccurate for the diagnosis of mesothelioma, and open or thoracoscopic biopsy is required. Accurate diagnosis of mesothelioma is difficult: the epithelial variant must be differentiated from adenocarcinoma, whereas the sarcomatous form often resembles benign sarcomas. Immunohistochemistry using a panel of antibodies, and sometimes electron microscopy, is required for all cases. Relentless local spread is typical, and chest CT or MRI is essential to evaluate potential local extension into the chest wall, pericardium, mediastinum, or diaphragm. Metastatic disease is less common and occurs late (if at all) in the disease course, so head CT and bone scans are indicated only if clinical findings are suspicious for metastasis.

40. Which of the following statements about therapy for malignant pleural mesothelioma is/are correct?
A. The role of surgery is confined to biopsy for diagnosis and pleurodesis for palliation of effusion.
B. Extrapleural pneumonectomy involves resection en bloc of the lung, visceral and parietal pleura, pericardium, and diaphragm.
C. If a lesion is unresectable by extrapleural pneumonectomy, pleurectomy/decortication is contraindicated.
D. Neither surgery, chemotherapy, nor radiation therapy as a single therapy improves survival.
E. Multimodality therapy, combining surgery, chemotherapy, and radiation therapy may improve survival in select patients.
Answer: BDE

DISCUSSION: In debilitated patients, palliation by pleurodesis is indicated; however, cytoreductive techniques, including pleurectomy/decortication, and extrapleural pneumonectomy, are indicated for patients who can tolerate surgery. For Stage I disease, extrapleural pneumonectomy is offered. If the patient cannot tolerate pulmonary resection or if the lesion is unresectable by extrapleural pneumonectomy, pleurectomy/decortication is appropriate. Both cytoreductive procedures, when used in a multimodality setting, may improve survival in selected patients. They also improve quality of life by relieving or delaying two severe symptoms of mesothelioma: dyspnea secondary to lung restriction by the tumor and pain from tumor invasion. No single modality (surgery, chemotherapy, or radiation therapy) improves survival.

41. All of the following may be acceptable operative approaches to management of the thoracic outlet syndrome except:
A. Scalenectomy.
B. Excision of a cervical rib.
C. Thoracoplasty.
D. First rib resection.
E. Division of anomalous fibromuscular bands.
Answer: C

DISCUSSION: Supraclavicular decompression of the thoracic outlet is the preferred operative approach for the thoracic outlet syndrome. This procedure consists of extensive anterior scalenectomy, middle scalenectomy, removal of a cervical rib (if present), and, on occasion, first rib resection. Transaxillary first rib resection has been widely used as well but is associated with a greater risk for complications. Numerous fibromuscular anomalies have been described in association with the thoracic outlet syndrome. Thoracoplasty has no role in the management of this disorder.

42. Initial conservative (nonsurgical) management of the thoracic outlet syndrome may include all of the following except:
A. Weight reduction.
B. Improvement of posture.
C. Exercises to strengthen the muscles of the shoulder girdle.
D. Pentoxifylline.
E. Avoiding hyperabduction.
Answer: D

DISCUSSION: The initial management of the thoracic outlet syndrome is nonoperative. A trial of weight reduction, shoulder girdle strengthening exercises, improvement of posture, and avoidance of hyperabduction should be recommended for 4 months or longer. These measures are successful in 50% to 70% of patients, particularly in young to middle-aged females with poor posture. Pentoxifylline is a hemorrheologic agent used in selected patients with peripheral arterial insufficiency and has no known benefit in the thoracic outlet syndrome.

43. Which of the following statements about pectus excavatum are correct?
A. It is the most common congenital malformation of the chest wall.
B. The most frequent presenting complaint is the cosmetic deformity.
C. The manubrium and first and second costal cartilages typically are involved in the deformity.
D. It may be associated with cardiac defects and other skeletal defects such as scoliosis.
E. Restrictive alterations in chest wall mechanics and abnormalities in pulmonary function tests have been documented.
Answer: ABDE

DISCUSSION: Congenital deformities of the chest wall represent a spectrum of deformities ranging from minor cosmetic defects to gross deformities incompatible with life. Pectus excavatum, or funnel chest, is the most common of the congenital deformities of the chest wall, accounting for 90% of such defects. It is characterized by a concave, posteriorly displaced sternum due to overgrowth of the costal cartilages. Most commonly the defect begins at the junction of the manubrium and the body of the sternum and becomes progressively deeper toward the xiphoid. The manubrium and the first and second costal cartilages typically are normal. The defects have both physiologic and psychologic consequences and are often associated with other abnormalities, including congenital heart disease, Marfan's syndrome, and other skeletal defects, including scoliosis. Patients most often present because of the cosmetic defect but frequently are found to have other symptoms, including impaired cardiopulmonary function and scoliosis. Pulmonary complaints include dyspnea and respiratory tract infections. Restrictive alterations in chest wall mechanics and abnormalities in pulmonary function tests, including decreased vital capacity, decreased total lung capacity, decreased maximal ventilatory volume, and decreased maximal breathing capacity, have been documented.

44. Surgical correction of pectus excavatum is characterized by which of the following?
A. Significant cosmetic improvement initially but a high incidence of recurrence of the defect on late follow-up.
B. An increase in exercise tolerance and respiratory reserve postoperatively.
C. Improvement in FEV 1, vital capacity, and total lung capacity.
D. Improvement in maximal ventilatory volume, total progressive exercise time, and maximal exercise capacity.
E. Prevention of the development of “thoracogenic scoliosis.”
Answer: BDE

DISCUSSION: Because of the significant cosmetic and psychological improvement, subjective increase in exercise tolerance, documented improvement in cardiac and respiratory status, and prevention of the development of scoliosis following surgical intervention in these patients, surgical correction should be considered for all patients with moderate to severe deformity. Cosmetic results of surgical correction are excellent, and recurrence is uncommon. Objective improvement in cardiac function has been documented postoperatively, owing to relief of the sternal compression. Postoperatively, worsening of the FEV 1, vital capacity, and total lung capacity have been noted, whereas a significant improvement in maximal ventilatory volume, total progressive exercise time, and maximal oxygen consumption has also been documented. Following surgical correction there is a consistent increase in maximal exercise capacity at every level of workload, a lower heart rate at every workload, and an increase in exercise duration.

45. Which of the following statements about the diagnosis of chest wall tumors is/are correct?
A. Pain is a common presenting symptom.
B. Firmness and fixation to underlying bone and muscle are important to note in the physical examination as aids to diagnosis.
C. In general, chest wall tumors are slow growing and produce symptoms late in their course.
D. CT is the most useful imaging study for making the diagnosis and for planning surgical resection of chest wall tumors.
E. Angiography should be performed routinely.
Answer: BCD

DISCUSSION: Seventy-five per cent of patients present with a slow-growing, painless chest wall mass. A firm mass that is fixed to an underlying rib is more likely to be of bony or cartilaginous origin. Conversely, soft, mobile tumors are more likely to be of soft tissue origin. CT defines depth of invasion and extent of tumor and is the most useful imaging modality. Angiography should be employed selectively, primarily for very large and vascular tumors.

46. Which of the following statements about chest wall resection and reconstruction is/are correct?
A. Most tumors of soft tissue and bone require 4-cm. margins to be adequately resected.
B. At least one normal rib above and below the primary tumor should be included in the resection.
C. Techniques of chest wall reconstruction are directed at the prevention of paradoxical chest wall movement with respiration.
D. Soft tissue defects are most conveniently addressed by stretching the existing skin over the defect under tension.
E. Chest wall defects that are covered by the scapula require no special reconstructive procedures, even if the defects are quite large.
Answer: ABCE

DISCUSSION: Margins of resection of chest wall tumors should be at least 3 cm. of skin, 4 cm. of muscle, and 6 cm. of bone. Old biopsy sites should be included in the specimen. A normal rib above and below the specimen should also be included. Prevention of paradoxical chest wall movement is the primary goal of chest wall reconstruction. Large soft tissue defects are best managed by myocutaneous pedicle flaps. In general, defects larger than 5 cm. require reconstruction. Defects covered by the scapula require no reconstruction.

47. Prolonged extracorporeal membrane oxygenation (ECMO):
A. Is highly successful in the treatment of severe respiratory failure in newborn infants.
B. Is contraindicated in adult respiratory distress syndrome (ARDS).
C. Causes hemolysis and renal failure.
D. Requires total systemic heparinization (activated clotting time longer than 500 seconds).
E. Is identical to heart/lung bypass for cardiac surgery.
Answer: A

DISCUSSION: The survival rate of newborn infants who are moribund from respiratory failure with ECMO is 80% to 90%. ECMO is also indicated in ARDS with a survival rate from 40% to 50%. Hemolysis and renal failure are rare complications. ECMO requires low-dose partial heparinization, with clotting times in the range of 200 seconds. Several modifications in the conventional heart/lung machine permit the extension of ECMO from hours to days.

48. Indications for ECMO include:
A. Newborn infants with pulmonary hypoplasia secondary to congenital diaphragmatic hernia.
B. Meconium aspiration syndrome in full-term babies (at least 35 weeks).
C. Children with pulmonary infection after bone marrow transplantation.
D. Adults with acute viral pneumonia.
E. Adults requiring mechanical ventilation and 100% oxygen for 2 weeks or longer.
Answer: BD

DISCUSSION: At present ECMO is not used for infants smaller than 1500 gm. because of a high risk of intracranial bleeding. ECMO is very successful in the treatment of respiratory failure in full-term newborn infants. Immunosuppression is a relative contraindication to ECMO. ECMO is indicated in adults with acute, potentially reversible respiratory failure, but mechanical ventilation and high oxygen concentration for more than 10 days are contraindications.

49. Venovenous ECMO:
A. Avoids major arterial access.
B. Provides cardiac and pulmonary support.
C. Can be accomplished via cannulation at separate venous sites or at a single venous site using a double-lumen catheter.
D. Provides greater venous drainage than venoarterial ECMO.
E. Maintains the normal pulsatile blood flow to the systemic circulation.
Answer: ACE

DISCUSSION: Venovenous ECMO has become the access technique of choice for patients with respiratory failure without significant requirement for cardiac (hemodynamic) support. In neonates, a double-lumen cannula allows ECMO to be performed through a single incision over the right internal jugular vein. It can also be performed by separate cannulation of the femoral and jugular veins. In either configuration, venovenous ECMO avoids cannulation of any major arteries and maintains the normal pulsatile circulation through the heart and lungs. Venous drainage is no different with venovenous ECMO.

50. As compared with venovenous ECMO, venoarterial ECMO:
A. Requires cannulation of a major artery and vein.
B. Provides both cardiac and respiratory support.
C. Can be performed with less anticoagulation.
D. Usually maintains a normal pulse pressure.
Answer: AB

DISCUSSION: Venoarterial ECMO can provide total cardiorespiratory support via cannulation of a major vein and artery (usually the right internal jugular vein and common carotid artery in neonates). With most roller and vortex pumps, the arterial inflow from the ECMO circuit is nonpulsatile, and therefore pulse pressure is often reduced or absent. Venoarterial ECMO requires the same degree of anticoagulation as venovenous techniques.

51. A 24-year-old male has new onset of chest pain. Chest films demonstrate a large anterosuperior mass. Appropriate evaluation should include:
A. CT of the chest.
B. Measurement of serum alpha-fetoprotein and beta–human chorionic gonadotropin.
C. A barium swallow.
D. A myelogram.
Answer: AB

DISCUSSION: Elevated levels of serum alpha-fetoprotein and beta–human chorionic gonadotropin are indicative of a malignant nonseminomatous germ cell tumor. Optimal therapy for such a tumor is based on a cis-platinum-containing chemotherapeutic regimen. After normalization of serum markers, resection of residual disease is performed. Extensive surgical procedures prior to chemotherapy are not warranted. Confirmation of the diagnosis can usually be obtained using needle biopsy techniques. In some institutions patients are treated based on elevated serum markers alone. CT imaging is useful to evaluate tumor invasiveness, airway compression, vascular involvement, and the likelihood of resectability. Barium swallow may be helpful in the evaluation of enteric cysts. Myelography may be useful in patients with posterior mediastinal masses to evaluate for spinal column involvement.

52. Systemic syndromes frequently associated with mediastinal tumors include:
A. Myasthenia gravis.
B. Hypercalcemia.
C. Malignant hypertension.
D. Carcinoid syndrome.
Answer: ABC

DISCUSSION: Myasthenia gravis occurs in 10% to 50% of patients with thymoma. The incidence with which myasthenia gravis occurs in patients with a thymoma increases with the age of the patient. In males over 50 and females over 60 years of age, the incidence appears to be greater than 80%. Hyperparathyroidism due to a mediastinal parathyroid adenoma is a cause of hypercalcemia. Although parathyroid glands may occur in the mediastinum in 10% of the patients, they are usually accessible through a cervical incision. A sternotomy is required infrequently, even in those patients with a mediastinal parathyroid gland. Most often the adenomas are found embedded in or near the superior pole of the thymus. Mediastinal paraganglioma may produce significant catecholamines, predominantly norepinephrine. Catecholamine production causes a classic group of symptoms associated with pheochromocytomas, including periodic sustained hypertension often accompanied by orthostatic hypotension, and hypermetabolism manifested by weight loss, hyperhydrosis, palpitation, and headaches. Mediastinal carcinoid tumors have been more frequently associated with Cushing's syndrome because of the production of adrenocorticotrophic hormones. These tumors uncommonly cause the carcinoid syndrome.

53. A 36-year-old female developed dyspnea on exertion that has progressed over 3 months. Chest film reveals a left anterior mediastinal mass with evidence of elevated left hemidiaphragm. CT indicates probable invasion of the pericardium. Paratracheal or subcarinal adenopathy is not identified. Appropriate intervention in this patient would include:
A. A median sternotomy with radical resection of the tumor, sacrificing the left phrenic nerve and excising the involved pericardium.
B. A mediastinoscopy with biopsy.
C. A left anterolateral thoracotomy or median sternotomy with generous biopsy of the tumor.
D. Observation with repeat chest radiography in 3 months.
Answer: C

DISCUSSION: The differential diagnosis of an invasive anterosuperior mediastinal mass includes thymoma, lymphoma, germ cell tumor, undifferentiated carcinoma, and carcinoid tumors. These tumors often have a very similar histologic appearance, which may cause an inaccurate diagnosis based on light microscopy alone. Use of electron microscopy and immunohistochemistry may be necessary to correctly determine the specific histologic diagnosis. Frozen section should be used to determine adequacy of tissue biopsy. Histologic diagnosis based on frozen section examination in many of these tumors may be erroneous. Although radical resection of tumor is indicated for thymoma, chemotherapy and radiotherapy are the modalities used for the treatment of patients with lymphomas and germ cell tumors. Exact determination of tumor histology by permanent section should precede radical resectional therapy. Generous tissue biopsy is necessary for the precise subtyping of lymphomas. Mediastinoscopy is useful in patients with paratracheal and pericarinal masses or adenopathy, particularly when right-sided. Observation of a patient with invasive mediastinal mass is not warranted.

54. An 18-year-old male presents with a history of increasing shortness of breath that worsens in the recumbent position. On physical examination, the neck veins are noted to be distended, with facial plethora that is accentuated by lying the patient down. A 2.5-cm. left supraclavicular lymph node is palpable. Chest film reveals an extensive right anterosuperior mediastinal mass. Appropriate intervention may include:
A. An urgent biopsy of the mediastinal mass under general anesthesia with subsequent initiation of therapy.
B. CT.
C. Pulmonary function testing in the sitting and supine positions.
D. A biopsy of the right supraclavicular lymph node under general anesthesia.
E. A biopsy of the supraclavicular lymph node under local anesthesia.
Answer: BCE

DISCUSSION: Although most patients with a mediastinal mass may undergo surgical procedures under general anesthesia with a minimal risk, patients with a large anterior, superior, or middle mediastinal mass, particularly those with posture-related dyspnea and superior vena caval syndrome, have an increased risk of developing severe respiratory complications during general anesthesia. Useful techniques for identifying less symptomatic patients who have significant airway compression include CT imaging and pulmonary function tests. A reduction of the tracheal diameter by more than 35% on a CT scan and reduction of peak expiratory flow during pulmonary function testing are sensitive indicators of functional airway compression. In patients with airway compression and superior vena caval obstruction, the risk of general anesthesia is significant. Attempts to obtain a histologic diagnosis should be limited to needle biopsies or open procedures performed under local anesthesia. In situations in which histologic diagnosis cannot be obtained using these methods, therapy may be initiated with radiation, corticosteroids, and chemotherapy. However, a histologic diagnosis may not be obtainable in as many as 40% of these patients after initiation of treatment. Some proceed with biopsy of the mediastinal mass under general anesthesia. However, alterations in anesthetic management include: (1) induction of anesthesia in a semi-Fowler's or upright position, (2) availability of rigid bronchoscopy to allow reestablishment of an adequate airway, (3) use of a long endotracheal tube to allow advancement of the tube beyond the site of obstruction, (4) avoidance of muscle relaxants and the use of spontaneous ventilation when possible, (5) lower extremity intravenous cannulation, and (6) standby cardiopulmonary bypass.

55. A 42-year-old male who is scheduled to undergo elective knee surgery has a preoperative chest film that demonstrates a 5-cm. posterior mediastinal mass. The patient denies any neurologic symptoms and physical examination fails to elucidate any neurologic deficit. CT confirms the presence of a 5-cm. mediastinal mass in the left costovertebral gutter with minimal enlargement of the seventh thoracic foramen. Appropriate intervention includes:
A. Resection of the posterior mediastinal mass using a standard posterolateral incision.
B. A CT with myelography or magnetic resonance (MR) imaging.
C. Two-stage removal of the tumor, performing the resection of the thoracic component first with subsequent removal of the spinal column component at a later date.
D. One-stage removal of the dumb-bell tumor, excising the intraspinal component prior to resection of the thoracic component.
Answer: BD

DISCUSSION: Approximately 10% of neurogenic tumors extend into the spinal column and are termed dumb-bell tumors because of the characteristic shape. Although 60% of patients with such tumors have neurologic symptoms related to spinal cord compression, the significant proportion of patients without symptoms underscores the importance of evaluating all patients with a posterior mediastinal mass for possible intraspinal extension. CT, MR imaging, and vertebral tomography may demonstrate an enlargement of the foramen, erosion of bone, or intervertebral widening, which are indicative of a dumb-bell tumor. If these findings are present, CT with myelography or MR imaging is indicated to evaluate the presence and extent of the intraspinal component. A one-stage removal of the tumor is recommended, with excision of the intraspinal component prior to resection of the thoracic component to minimize the risk of spinal column hematoma.

56. True statements regarding patients with a mediastinal mass include:
A. Asymptomatic patients have a benign mass in over 75% of cases.
B. Symptomatic patients are more likely to have a malignant lesion than a benign lesion.
C. In a patient with a chest film demonstrating a mediastinal mass, a Tru-cut needle biopsy is a safe procedure.
D. Seminomas usually produce alpha-fetoprotein.
Answer: AB

DISCUSSION: Seventy-six per cent of the asymptomatic patients with a mediastinal mass seen in one series over a recent 20-year period had a benign leison. In contrast, 62% of the symptomatic patients had a malignant neoplasm during this period. A number of intrathoracic and extrathoracic lesions may have an appearance similar to a primary mediastinal mass on routine chest films, as do a large number of cardiovascular lesions. Although angiography was used in the past for this differentiation, CT with contrast and MRI now distinguish a primary mediastinal mass from a cardiovascular lesion. Tru-cut needle biopsy of a cardiovascular lesion may be associated with significant hemorrhagic complications. Seminomas rarely produce beta–human chorionic gonadotropin and never produce alpha-fetoprotein. In contrast, over 90% of the nonseminomas secrete one or both of these hormones.

57. Which of the following would be the least appropriate in the management of acute suppurative mediastinitis?
A. Wide débridement.
B. Irrigation under pressure.
C. Topical antibacterials.
D. Long-term systemic antibacterials.
E. Closure with muscle flaps.
Answer: D

DISCUSSION: Acute suppurative mediastinitis is a classic wound problem and forms a paradigm for principles of management. Wide débridement is perhaps the most important step in correcting this type of invasive wound sepsis. Drainage requires removal of tissue with vascular compromise. Tissue that is infected and can serve as an ongoing nidus for infection, particularly cartilage, must be removed. Irrigation is effective only when the irrigation fluid reaches into and flushes out débris and bacteria. The irrigation is insufficient if only dilutional and not also mechanically effective. Since infected tissue tends to become isolated from the systemic circulation the direct application of antibacterials reaches avascular areas. Some, such as silver sulfadiazine, penetrate avascular tissue better than, for instance, ointments or povidone iodine, and such an agent should be chosen. Wide débridement and the washing of debris with pressure irrigation make the wound then available to topical applications, which are often best packed into these deep, irregular cavities. Long-term systemic antibacterials serve no purpose and lead to potential resistant bacterial overgrowth. Although systemic antibacterials provide a measure of protection up to the margin where vascularized and nonvascularized tissues meet, topical agents are better in the actual infected site. Once closed, these wounds rapidly become sterilized. Even the infection at the bone level is far different from traditional osteomyelitis, and long-term systemic therapy is unnecessary. Muscle flaps are a great advance in closure technique, since they provide bulky protection, obliterate dead space, and help vascularize the wound.

58. Each of the following is appropriate for managing acute suppurative mediastinitis except:
A. Alloplastic material and skin flaps.
B. Rectus abdominis muscle flaps.
C. Omentum.
D. Pectoralis major muscle flaps.
E. Rigid internal fixation.
Answer: A

DISCUSSION: Alloplastic materials may be nonreactive in the laboratory and biologically acceptable in other areas (artificial hips, breast prostheses). Their introduction into a contaminated wound, however, would more likely promote rather than reduce infection. Various meshes and other types of “protection” devices are not necessary. Skin flaps alone do not obliterate dead space and have not been shown either to reduce or resist infection. The rectus abdominis muscle is a superb source of readily available tissue that can be rotated into very large cavities. The nature of the muscle allows it to be “dressed into” irregular cavities. It has an excellent, easily movable skin territory overlying it, which can also be transferred if locally available skin is wanting. The omentum has the great ability to fit into the many irregularities of some defects. For appropriately selected cases it is excellent. The pectoralis major muscle flaps are the usual initial choice since they are in the operative field. When the musculotendinous insertion is released their mobility is often sufficient. Additionally, it avoids the need for abdominal incisions. The latissimus dorsi muscle as a flap is dependable and includes sternal defects in the scope of its arc of rotation. It requires rotating the patient on the operating table and thus is less readily available than the other flaps.

59. Clinical features suggestive of myasthenia gravis include all of the following except:
A. Proximal muscle weakness.
B. Diplopia.
C. Sensory deficits of the extremities.
D. Dysphagia.
Answer: C

DISCUSSION: Weakness of proximal weight-bearing muscle groups is the hallmark of the clinical diagnosis of myasthenia gravis. The weakness or fatigue occurs with repetitive activity and improves with rest. The majority of patients (90%) experience ocular muscle involvement, manifested as diplopia or ptosis most easily demonstrated with sustained upward gaze. Cranial nerve involvement is uncommon but can be present, with symptoms of dysphagia, nasal regurgitation, and aspiration. Since myasthenia gravis is a disorder of neuromuscular transmission at the motor end plate, deep tendon reflexes and sensory examination are normal.

60. The diagnosis of myasthenia gravis can be confirmed most reliably using:
A. Anti–acetylcholine receptor antibody titers.
B. The Tensilon test.
C. Electromyography (EMG).
D. Single-fiber EMG.
E. Physical examination.
Answer: D

DISCUSSION: Although findings from a careful history and physical examination are suggestive of the diagnosis of myasthenia gravis, specific diagnostic testing is required to confirm the diagnosis. Elevated anti–acetylcholine receptor antibodies are present in 85% to 90% of patients with generalized myasthenia but are often negative in patients with early or ocular myasthenia gravis. The Tensilon test is also positive in approximately 90% of patients with generalized myasthenia gravis, but both false-negative and false-positive results occur, especially in patients with mild or early disease. Standard EMG studies are helpful if positive, but their overall sensitivity may be as low as 35%. The specialized technique of single-fiber EMG is the most reliable diagnostic test, being abnormal in 90% of patients with mild disease and in virtually 100% in patients with severe generalized myasthenia gravis.

61. All of the following statements are true about the pathogenesis of myasthenia gravis except:
A. The number of functional acetylcholine receptors at the motor end plate is reduced.
B. An autoimmune mechanism involving antibodies to the acetylcholine receptor has been proposed.
C. Complement system involvement has been demonstrated.
D. A nonspecific “thymitis” may initiate the autoimmune response.
E. Clinical improvement following thymectomy is correlated with decreased acetylcholine receptor antibody titers.
Answer: E

DISCUSSION: Myasthenia gravis is generally regarded as an autoimmune disorder due to antibodies directed toward the acetylcholine receptor. A variety of autoimmune mechanisms have been proposed; the ultimate result is a reduction in the number of functional acetylcholine receptors at the motor end plate. Proposed immune mechanisms include complementmediated receptor destruction, antibody-induced accelerated receptor turnover, and simple receptor blockade. In spite of these proposed immune mechanisms, the severity of myasthenia symptoms and improvement following therapy do not correlate with antibody titers. Although the source of these autoantibodies is not proven, it is generally felt that a nonspecific thymitis may trigger the autoantibody response, the thymic myoid cells serving as the source of the antigen.

62. Which of the following statements about the relationship of the thymus and myasthenia gravis is/are true?
A. Thymic abnormalities are present in up to 80% of patients with myasthenia gravis.
B. Thymoma is present in up to 20% of patients with myasthenia gravis.
C. Myasthenia gravis will occur in up to 60% of patients with thymomas.
D. Myasthenia patients with thymoma respond more favorably to thymectomy.
E. Thymoma is the most common abnormality of the thymus in patients with myasthenia gravis.
Answer: ABC

DISCUSSION: The central role of the thymus gland in the pathogenesis of myasthenia gravis is based on the observation that more than 80% of patients have histologic abnormalities of the thymus and on the beneficial effect of thymectomy on patients' symptoms. Of the patients with documented abnormalities of the thymus the majority have B-cell lymphoid hyperplasia; only 20% have a thymoma. Conversely, up to 60% of patients with known thymoma will have or ultimately develop myasthenia gravis. In these patients, with thymoma and myasthenia gravis, the response to thymectomy is less favorable than in those without thymoma.

63. Which of the following statements about the results of thymectomy for myasthenia gravis are true?
A. Patients with ocular symptoms experience clinical improvement in 90% of cases.
B. Clinical remission can be expected in 90% of cases.
C. The response rate to thymectomy for patients with generalized symptoms is 90%.
D. Patients with thymoma experience improvement in 75%.
E. Continued medical therapy is required in 75%.
Answer: C

DISCUSSION: Overall, improvement can be expected in 90% of patients who undergo thymectomy for generalized myasthenia gravis. In general, the results are more favorable in patients with mild generalized myasthenia. In patients with only ocular symptoms, the benefit following thymectomy is less clear; improvement is documented in 80%. The response rate is even less (30%) in patients with thymoma. Complete remission occurs in 40% to 50% of patients following thymectomy, and the remainder require some continued medical therapy.

64. All of the following are true of the treatment of myasthenia gravis except:
A. The transcervical approach to surgical thymectomy is less likely to benefit the patient with myasthenia gravis.
B. Corticosteroids result in improvement in 80% of patients.
C. Plasma exchange is associated with improvement in up to 90% of patients.
D. Medical therapy with Mestinon (pyridostigmine) is associated with remission in approximately 10% of patients.
E. Surgical thymectomy, regardless of the approach, is associated with improved remission and response rates as compared with medical therapy.
Answer: A

DISCUSSION: Although Mestinon therapy results in clinical improvement in most patients, complete remission can be expected in only 10%. In addition, intolerable side effects may limit their usefulness. In patients who fail to respond to Mestinon therapy, and in those who experience significant side effects, corticosteroids can be utilized, with improvement expected in 80% of patients. Plasma exchange results in improvement in 90% of patients, but the cost of therapy and its transient duration of benefit limit the use of pheresis therapy to special circumstances such as preoperative preparation or in myasthenic crisis. Overall, response rates to surgical thymectomy range from 80% to 95%, and complete remission occurs in 30% to 50%. This benefit following thymectomy has not been shown to depend on the particular technique utilized. Remission and response rates are similar for transcervical, standard transsternal, and the “maximal thymectomy” techniques.

65. Which of the following is/are acceptable alternatives in the management of malignant pericardial effusion?
A. Pericardiocentesis.
B. Subxiphoid pericardiotomy (“pericardial window”).
C. Thoracotomy with pericardiectomy.
D. Instillation of tetracycline or bleomycin into the pericardial space.
E. Treatment of the underlying malignancy.
Answer: ABCDE

DISCUSSION: In patients with symptomatic malignant pericardial effusions, management options may be designed to establish a diagnosis, relieve symptoms, or prevent recurrence. Pericardiocentesis is very successful in removing fluid for diagnosis and alleviating symptoms; however recurrence rates are greater than 50%. This rate can be reduced to around 20% with instillation of sclerosing agents such as tetracycline or bleomycin. Surgical techniques, including subxiphoid pericardiotomy and thoracotomy with pericardiectomy, offer the highest success rates (approximately 90%) but are more invasive and usually require general anesthesia. Systemic antitumor therapy with chemotherapy or radiation therapy can be effective in controlling malignant effusions in cases of sensitive tumors such as lymphomas, leukemias, and breast cancer.

66. Which of the following statements about cardiac tamponade is/are correct?
A. At least 500 ml. of fluid must be present in the pericardium of an adult to cause symptoms of tamponade.
B. A drop in systemic blood pressure of greater than 20 mm. Hg during inspiration (pulsus paradoxus) is a finding specific to cardiac tamponade.
C. The vast majority of patients with cardiac tamponade demonstrate a low QRS voltage, nonspecific ST T-wave abnormalities, and electrical alternans (alternation of QRS amplitude) on the electrocardiogram.
D. In trauma victims with cardiac tamponade, the three components of “Beck's triad” (hypotension, elevated jugular venous pressure (JVP), and muffled heart sounds) are almost always present.
E. When the diagnosis is made, treatment must be instituted rapidly and may include pericardiocentesis, creation of a pericardial window, and identification and treatment of the underlying cause.
Answer: E

DISCUSSION: Development of tamponade symptoms depends on the rate of accumulation of fluid. As little as 100 to 200 ml. accumulating rapidly may cause symptoms, whereas a slowly developing pericardial effusion of over 1 liter may remain asymptomatic. Pulsus paradoxus is not specific for tamponade; it may occur in patients with severe congestive heart failure, chronic obstructive pulmonary disease, hypovolemia, acute pulmonary embolism, or shock. Electrocardiographic findings of low QRS voltage and nonspecific ST T-wave changes are common in this condition, but electrical alternans, often considered pathognomonic of cardiac tamponade, is present in only a small number of patients. Trauma victims with tamponade frequently lack one or more of the elements of Beck's triad; for example, associated hypovolemia may lead to low or normal jugular venous distention. Since cardiac tamponade is life threatening, therapy designed to drain the pericardial fluid must be provided quickly and the underlying cause must be established and controlled.

67. Which of the following statements about constrictive pericarditis is/are correct?
A. Most patients who develop constrictive pericarditis after cardiac operation present with symptoms within 6 months of the procedure.
B. Results of pericardiectomy for constrictive pericarditis are worse in patients who develop constriction after mediastinal irradiation.
C. Drainage of asymptomatic pericardial effusions arising from acute pericarditis is advised to prevent development of constrictive pericarditis.
D. If surgical treatment is planned for constrictive pericarditis it should involve total or complete pericardiectomy.
E. Echocardiography can usually make the diagnosis by imaging a thickened pericardium.
Answer: BD

DISCUSSION: The time course in the development of constrictive pericarditis after cardiac surgery ranges from 1 month to nearly 9 years, but the mean interval from surgery to presentation is about 23 months. Most series have reported poorer outcomes from pericardiectomy for postirradiation constrictive pericarditis, possibly owing to underlying myocardial fibrosis. In this subset, 5-year survival averages 50%, as compared with 75% for constrictive pericarditis of all causes. Constrictive pericarditis is a rare complication of acute pericarditis. As a result, drainage of asymptomatic (nonpurulent) pericardial effusions from acute pericarditis is not required. Patients with significant symptoms from constrictive pericarditis should undergo total pericardiectomy, even though this procedure carries an operative mortality rate of approximately 10%. Limited pericardiectomy has proven to be ineffective for this condition. It can be difficult to distinguish constrictive pericarditis from restrictive cardiomyopathy. Echocardiography may help by demonstrating chamber dimensions and wall motion abnormalities, but CT and MRI more accurately assess pericardial thickness.

68. The relationship between small-cell and non-small cell lung cancers can be described by the following:

a. They differ by histology, clinical behavior and cell of origin
b. Of all lung cancers, approximately 80% are non-small cell and 20% are small cell
c. Both cell types are predictably responsive to chemotherapy
d. The International Staging System can be applied to both tumor types
e. The majority of non-small cell cancer patients vs. the minority of small cell cancer patients are candidates for pulmonary resection
Answer: b

Although small cell and non-small cell lung cancers do differ by histology and clinical behavior, they probably have a common origin since c-myc or n-myc amplified small cell lung cancer lines will undergo transition to non-small cell phenotypes after insertion of an activated ras/gene. The overall incidence of lung cancers is 80% non-small cell and 20% small cell. Only the small cell carcinoma is predictably responsive to chemotherapy.
The staging system for small cell lung cancer is based on limited vs. extensive disease outside of a tolerable radiotherapy portal while the International Staging System uses TNM descriptors for 4 clinical stages. Unfortunately, only about 30% of patients with non-small cell lung cancer have potentially resectable tumors.

69. A 62-year-old male smoker presents with right anterior chest pain. There is a 3 cm mass attached to the chest wall with radiographic evidence of rib erosion and positive cytology for non-small cell carcinoma. Which of the follow is/are true:

a. The patient is inoperable due to tumor size and chest wall involvement
b. Radiation therapy is the preferred initial treatment
c. Operative resection should be performed with en bloc removal of the tumor and adjacent chest wall as well as a mediastinal lymph node resection
d. Positive mediastinal nodes will have little effect on survival
e. The patient would be classified Stage IIIa
Answer: c, e

Survival after resection for non-small cell lung cancer is related to the stage of the disease with a strong adverse effect from nodal involvement. This is true even for large peripheral tumors that extend into the chest wall as in this case where a 40–50% survival would be expected in the absence of nodes (T3N0:Stage IIIa) but only a 15% survival with nodal involvement. Radiation therapy would be a postoperative consideration to reduce the incidence of local recurrence. En bloc operative resection of the involved lobe and mediastinal nodes for staging would offer the greatest likelihood of cure.

70. For the patient in the pervious question to become an operative candidate which of the following must be met?

a. Extrathoracic metastases must be able to be controlled by another modality, e.g. radiotherapy
b. Tumor doubling time must exceed 40 days
c. If there is recurrence at the primary site, it must be treated before the metastatic disease
d. Even if effective systemic therapy is available, resection of metastases is preferred
e. If pulmonary reserve is marginal, resection of the maximal number of metastatic foci should be performed
Answer: c

There are a number of controversial areas in the area of operative approaches to metastatic disease in the lung, but there is general agreement that any extrathoracic metastases preclude eligibility for pulmonary resection. Although tumor doubling time is a measure of its aggressiveness, it is too variable to have prognostic significance and is generally disregarded as a criterion for resection. Primary site recurrence must be treated before the metastatic focus to prevent further seeding. If effective systemic therapy is available as would be expected in breast and testicular cancer or osteogenic sarcoma, it is preferred over surgical resection. Similarly, pulmonary resection should not be undertaken unless the pulmonary reserve will allow all metastatic foci to be resected.

71. Biopsy of the lesion in the previous question is reported as “bronchial carcinoid with no signs of atypia.” Which of the follow is/are true?

a. Sleeve resection of the bronchus would be appropriate
b. Lymph node biopsy at time of resection is unnecessary
c. Associated carcinoid syndrome is very unlikely
d. If carcinoid syndrome were found in a tumor this size, hepatic metastases would be likely
e. When bronchial carcinoid syndrome occurs, right-sided cardiac valves are affected
Answer: a, c, d

In the absence of atypia, carcinoids are only locally malignant and can be managed by limited lung and/or bronchial resection. Therefore, a sleeve resection of the bronchus preserving distal lung would be appropriate. Lymph node sampling at the time of resection, however, is advisable to ensure that a complete resection has been performed. The carcinoid syndrome is rarely found except in the presence of a large primary tumor or hepatic metastases. When the carcinoid syndrome does occur, it is left-sided cardiac valves that are affected rather than right, which one would expect with gastrointestinalcarcinoids.

72. In the evaluation and preparation of a 55-year-old smoker for resection of a 3 cm pulmonary adenocarcinoma, the following is/are true:

a. Preoperative cessation of smoking does not reduce postoperative pulmonary complications
b. Resting PaCO2 is of more value than PaO2
c. FEV1 is of more value than measured vital capacity
d. Diffusion capacity should be measured routinely
e. V/Q lung scan is useful when pulmonary reserve is marginal
Answer: b, c, e

Preoperative cessation of smoking for a period of 2 weeks can reduce pulmonary complications and should be required. In the preoperative assessment for pulmonary resection, the PaCO2 is of more value than the PaO2 since an elevated PaCO2 > 50 mmHg identifies the very high risk patient with chronic lung disease. Hypoxemia may be secondary to the mechanical effects of the tumor producing ventilation/perfusion mismatch. The latter can be confirmed by V/Q lung scan which also serves to identify areas of functioning lung in patients with marginal pulmonary function. The best screening test for adequacy of pulmonary reserve is the FEV1. It identifies obstructive pulmonary disease which is more important than the restrictive lung disease identified by vital capacity measurement. Diffusion capacity measurement provides little additional information of value.

73. Following resection of a T1N1 squamous cell cancer in a 47-year-old male, the following is/are true:

a. There is a higher risk of local recurrence than with any other histologic type of non-small cell cancer
b. The greatest risk to the patient is a distant metastasis
c. Of all metastatic sites, liver is most likely
d. If the patient survives five years, there is a greater risk of a new lung cancer than recurrence
e. To improve survival, the patient should be considered for adjuvant chemotherapy
Answer: a, b, d

The risk of local recurrence for non-small cell carcinomas of the lung is much more common for those of squamous cell histology than the others and averages 20%–30% overall. The greatest risk, however is of distant metastases which occur in 70%–80% of patients, regardless of stage. Almost all recurrences are seen within five years, and of the distant metastatic sites, the brain is most commonly affected. In this patient with Stage II disease, radiation therapy would be a consideration to reduce the incidence of local recurrence, but not chemotherapy. After five years, the highest risk would be from a new lung cancer rather than a recurrence.

74. A 42-year-old woman with hemoptysis is seen to have a 2 cm mulberry appearing polypoid lesion in the left mainstem bronchus suspicious for bronchial adenoma. The differential diagnosis includes which of the following:

a. Mucoepidermoid carcinoma
b. Plasma cell granuloma
c. Carcinoid tumor
d. Adenoid cystic carcinoma
e. Mucous gland adenoma
Answer: all of the above

The term bronchial adenoma includes a spectrum of tumors arising from epithelial stem cells which vary from the benign mucous gland adenoma to the malignant adenoid cystic and mucoepidermoid carcinomas as well as the carcinoid tumors of similar varied behavior. Among these variants, the carcinoid are most common representing 80%–90% of all bronchial adenomas.

75. A 42-year-old man has a solitary “coin lesion” 2 cm in diameter in the area of the right upper lobe on a routine chest radiograph. Which of the following is/are true?

a. A previous radiograph from five years prior showing the lesion to be 1.2 cm in diameter indicates malignancy
b. If a CT scan shows mediastinal adenopathy, mediastinoscopy is preferable to thoracotomy
c. In the absence of previous radiographs, the lesion should be followed by serial films at 6 month intervals
d. Calcification in a concentric or “popcorn” configuration denotes a benign lesion
e. Needle aspiration showing “chronic inflammatory cells” denotes a benign lesion
Answer: b, d

In the evaluation of a solitary lung lesion, previous radiographs are important, particularly if the lesion is new. A coin lesion that is growing slowly does not necessarily indicate malignancy, since the most common benign tumor, hamartoma, has a variable pattern of slow growth and typically will show “popcorn” calcification. Concentric calcification is also most suggestive of a benign granuloma. In the absence of previous radiographs, the lesion must be assumed to be malignant until proved otherwise and should not be dismissed to follow-up. If a CT scan shows mediastinal adenopathy, then mediastinoscopy with biopsy is appropriate to make a diagnosis. Needle aspiration results of “chronic inflammatory cells” is non-diagnostic.

76. A 2 cm peripheral squamous cell carcinoma in the lung of a 60-year-old male with a pleural effusion positive for malignant cells would be classified as:

a. T1N0M1
b. T3N0M0
c. T3N0M1
d. T4N0M0
e. T4N0M1
Answer: d, e

The presence of a pleural effusion in association with a primary lung cancer is usually an ominous sign precluding surgical resection. However, if more than one sample of the effusion is negative for malignant cells and it is non-bloody, it can be considered unrelated to the tumor and excluded as a staging element. When the effusion cytology is positive, the tumor is considered T4 regardless of size or nodal status.

77. A 53-year-old woman who had a malignant tumor removed 2 years ago presents with a solitary lung nodule 1.5 cm in diameter. The following is/are true:

a. If the primary tumor originated in the breast, the lesion is most likely to represent a new primary lung cancer.
b. If the primary tumor was melanoma, the lesion is most likely to be metastatic
c. If the remainder of the lung fields are clear, a CT scan is unnecessary
d. If the primary tumor was in the GI tract, there is very little chance that the lesion is a new primary lung cancer
e. Fine needle aspiration should always be performed prior to resection of the lung lesion
Answer: a, b

A new pulmonary lesion in a patient with a history of a previously treated malignancy poses a diagnostic and therapeutic challenge. A CT scan should always be obtained since plain radiographs can detect lesions only 9 mm in diameter or greater. The lesion is most likely to be metastatic if the prior malignancy was sarcoma or melanoma and most likely to be a new primary lung cancer if the prior malignancy originated in the head, neck or breast. When the original lesion was in the GI or GU tract, there is an equal chance that it is metastatic or a new primary. Fine needle aspiration does not usually alter the plan for excision and is done only when the patient is not an operative candidate or desires to know the diagnosis.

78. A 61-year-old male presents with a painful mass 3.5 cm in diameter below the clavicle and attached to the chest wall. The following is/are true:

a. A CT scan is the best study to determine rib destruction
b. The lesion should be removed enbloc without biopsy to minimize the chances for local recurrence
c. The chances are approximately 40% that the lesion is metastatic
d. If it is metastatic, the most likely primary tumor is in the lung or pancreas
e. Fortunately, less than 50% of chest wall tumors are malignant
Answer: c

Chest wall tumors are uncommon, accounting for only 1–2% of all body tumors. About 57% of chest wall tumors are primary, whereas 43% are metastatic. Solitary metastases most frequently arise from the thyroid gland, the GU tract and the colon. Overall, about 60% of chest wall tumors are malignant, most arising form bone or cartilage. The CT scan is of value in demonstrating the relationship between the mass and contiguous structures, but of little value in determining bone destruction because of the oblique course of the ribs. Specific rib films are most helpful. Now that multimodality therapy is available, core needle biopsies are recommended and have not increased the incidence of local recurrence.

79. Concerning the sternum, the following is/are true:

a. The xiphoid process is the anterior border of the thoracic outlet
b. Gladiolus is the body of the sternum
c. The angle of Louis is at the level of the 2nd costal cartilage
d. The 11th rib is attached via costal cartilage to the xiphoid
e. The sterno-manubrial junction is at the level of T4 posteriorly
Answer: a, b, c, e

The sternum consists of 3 segments, the upper manubrium, the body or gladiolus, and the xiphoid process which ends in the rectus sheath and has no costal attachments. The xiphoid marks the anterior border of the thoracic outlet. The junction of the manibrium and body is the sternal angle or angle of Louis which corresponds to the level of T4 posteriorly and attaches to the 2nd costal cartilage anteriorly.

80. A 22-year-old woman recovering from a traumatic head injury is noted to have bright red bleeding when her tracheostomy is suctioned. The following is/are true statement(s):

a. Antibiotics should be administered to treat the bronchitis
b. Deflation of the tracheal tube cuff is a useful diagnostic maneuver
c. If massive bleeding occurs, a finger should be used to compress the innominate artery against the sternum
d. Operative treatment of a tracheoinnominate fistula includes resection and prosthetic replacement of the innominate artery
e. Tracheal resection is usually required for a tracheoinnominate fistula to prevent recurrence
Answer: b, c

The complication of tracheoinnominate artery fistula characteristically occurs in young women and is often heralded by bleeding during the tracheostomy suctioning. Deflation of the tracheal tube cuff confirms the diagnosis if massive bleeding occurs. At that point the tracheal tube cuff should be overinflated and a finger inserted into the tracheostomy incision to tamponade the bleeding. Throughout this, the airway must be protected. Operative repair through an upper sternal split requires resection of the innominate and coverage of the oversewn vessels with viable tissue since the wound is contaminated. No prosthetic material should be inserted and tracheal resection is not necessary.

81. A 52-year-old alcoholic with fever and a cough productive of purulent sputum is found to have the opacity on chest film as shown (Fig. 62-15). The following is/are true statement(s):

a. The findings suggest a parapneumonic empyema
b. If pus is found on aspiration of the pleural space, a chest tube should be placed
c. If pus is found on aspiration, bronchoscopy is a necessary part of the patient’s evaluation
d. In this situation, rib resection for drainage is preferred to a large-bore chest tube
e. Decortication of the lung should be considered if the lung fails to expand within 4 weeks
Answer: a, b, c

The posterior location of the infiltrate and fluid collection is typical of a parapneumonic empyema. The most important test is pleural aspiration which will usually yield frank pus, at which time a chest tube should be placed. Formerly, oily Dionosil was used to perform an empyemagram; this substance is now no longer commercially available. In the case of parapneumonic empyemas, tube drainage alone may be sufficient to allow full expansion of the lung. If this is not the case, a formal rib resection or early decortication should be performed. Decortication or marsupialization is indicated if the lungs fail to expand after 6–8 weeks. Every patient with spontaneous empyema should undergo bronchoscopy to rule out endobronchial obstruction by foreign body or tumor.

82. The lesion shown (Fig. 62-6) was found on a 32-year-old male on a routine chest film required for his employment. Which of the following is/are true?

a. The stippled calcification and intact cortex of the rib are characteristic of osteochondroma
b. The stippled calcification is characteristic of osteogenic sarcoma
c. If the lesion is osteogenic sarcoma, the optimal treatment is resection and radiation therapy
d. If the lesion is an osteochondroma, it need not be resected in this age group
e. The radiographic picture is typical for Ewing sarcoma
Answer: a

Osteochondroma is the most common benign rib tumor and has a 3:1 male incidence. The stippled calcification and intact rib cortex are characteristic for this lesion in contrast to the bone destruction of Ewing sarcoma and combined bone destruction and “sunburst” calcification of osteogenic sarcoma. For both Ewing and osteogenic sarcoma, multimodality therapy using preoperative chemotherapy followed by resection yields better results than with radiation therapy. Osteochondromas in prepubertal children can be observed unless they become painful or enlarged, but are routinely resected in adults.

83. To resect a chondrosarcoma of the chest wall in a 42-year-old man, ribs 2–4 were removed, leaving a defect 8 x 8 cm. For reconstruction, the following is/are true:

a. If this were to be posterior, beneath the scapula, reconstruction would not be required
b. If this defect is anterior, the primary benefit of reconstruction is an improved cosmetic result
c. Whenever chest wall reconstruction is considered, it should be delayed 6–12 months to allow detection of recurrent tumor
d. If Marlex is used for reconstruction, no wound drainage tube is necessary
e. If PTFE is used for reconstruction, both pleural and wound tubes should be used
Answer: a, d, e

Skeletal chest wall defects that are full-thickness and occur posteriorly where they can be covered by the scapula do not require reconstruction. Anterior chest wall defects do require reconstruction, primarily to stabilize the chest wall and prevent paradoxical motion. The reconstruction should be immediate for optimal physiological benefit. Since Marlex mesh is porous, only a wound catheter is needed as pleural fluid will drain through it. PTFE, however, is a solid sheet necessitating both pleural and wound drainage.

84. An upright chest film of a cachectic, homeless 47-year-old woman shows blunting of the right costophrenic angle. The following is/are true:

a. A lateral decubitus film should be obtained to confirm the presence of fluid rather than a CT scan
b. Tuberculous effusion can readily be identified by stain and culture of aspirated fluid
c. A pleural fluid glucose level lower than in the serum is diagnostic of empyema
d. Bloody pleural effusion in this patient is diagnostic of an underlying malignancy
e. Pleural fluid cytology report of lumphoma should be viewed with skepticism
Answer: a, e

Although the CT scan is a very sensitive indicator of pleural effusion, a lateral decubitus is the simplest way to differentiate fluid from pleural thickening or fibrosis. Tuberculous pleuritis is difficult to diagnose by stain or culture which have a 30% yield, but the diagnosis is facilitated by needle biopsy of the pleura. Pleural fluid glucose lower than in serum is characteristic of rheumatoid arthritis, neoplasms, and tuberculosis as well as empyema. A red-tinged fluid can occur from needle trauma, but even frankly bloody fluid in this patient may reflect trauma as well as underlying malignancy. Pleural inflammation induces reactive changes in mesothelial cells that makes them resemble lymphocytes, so a lymphoma diagnosis is suspect.

Following shotgun wound of the chest wall, a 39-year-old woman desires reconstruction without a foreign-body prosthesis. Old incisions prohibit use of her rectus abdominus muscles. Considering chest wall muscles for reconstruction, the following is/are true statement(s):

85. The pectoralis major muscle is available and innervated by the medial and lateral pectoral nerves so named because it describes their relationship to the pectoralis minor
a. The serratus anterior muscle is available since its absence has no functional significance
b. There is no serratus posterior muscle
c. The latissimus dorsi muscle is available and supplied by the thoracodorsal artery
d. The latissimus dorsi is innervated by the thoracodorsal nerve with fibers from C6, C7 and C8
Answer: d, e

The pectoralis major muscle can be used for reconstruction but the medial and lateral pectoral nerves are named from their respective cords of the brachial plexus. The serratus anterior muscle holds the scapula to the chest wall and its absence produces the functional and cosmetically disabling winged scapula. The serratus posterior muscle is attached to the 7th cervical and first three thoracic vertebrae posteriorly and functions as an accessory muscle of respiration. The constancy of the vascular pedicle to the latissimus dorsi and its size allow this muscle to be used to reconstruct defects of the head, neck, chest wall and pleural cavity. It is innervated by the thoracodorsal nerve with fibers from C6, C7 and C8.

86. A 38-year-old man presents with facial and upper extremity edema, venous distention in the neck and arms and a cyanotic appearance. The following is/are true statement(s):

a. The most likely cause of the problem is mediastinal granulomatous disease
b. A venogram should be obtained to confirm the diagnosis
c. Mediastinoscopy for diagnosis is contraindicated
d. If a malignancy is identified, resection is indicated for palliation
e. If the etiology is benign disease, gradual improvement without operation is to be expected
Answer: e

Although mediastinal granulomatous disease is one cause of the superior vena cava syndrome described, the most common cause (75%) is malignant disease. A venogram adds little information to the typical findings and increases risk from extravasation of contrast medium subcutaneously from the venous hypertension. Mediastinoscopy can be used for diagnosis with recognition of increased risk of bleeding and airway problems from the edema associated with the endotracheal intubation required for the procedure. If a malignancy is found, operative resection is usually precluded by the extent of mediastinal invasion. Fortunately, in the case of benign disease, the symptoms tend to improve with time as chest wall and mediastinal collaterals enlarge.

87. A 39-year-old woman with hypertension and radicular chest wall pain was found to have the lesion seen on chest radiograph (Fig. 63-23). The following is/are true statement(s):

a. The location of the lesion suggests a teratoma
b. High urinary vanillylmandelic acid levels would indicate that the lesion is a paraganglioma
c. If the lesion was seen on a film 5 years earlier, resection would not be indicated
d. A neurosurgical consultation should be obtained
e. Vasoactive intestinal polypeptide level elevation suggests a ganglioneuroma
Answer: d, e

The posterior mediastinal location of the tumor is most indicative of a neurogenic tumor while teratomas are characteristically found in the anterior mediastinum. Neurogenic tumors can undergo malignant degeneration and should be resected, particularly in this symptomatic patient even if known to be present for years. The radicular pain suggests the possibility of intraspinous extension of the tumor, and therefore a neurosurgical consultation is appropriate. Both urinary vanillylmandelic acid elevation and vasoactive intestinal polypeptide can be produced by ganglioneuroma but would not be characteristic of a paraganglioma.

Cardiac Surgery MCQ

2008-09-06T19:09:00.000-07:00

1. Which is not true of cardiopulmonary resuscitation (CPR)?
A. Closed chest massage is as effective as open chest massage.
B. The success rate for out-of-hospital resuscitation may be as high as 30% to 60%.
C. The most common cause of sudden death is ischemic heart disease.
D. Standard chest massage generally provides less than 15% of normal coronary and cerebral blood flow.
Answer: A

DISCUSSION: Closed chest massage is not as effective as open-chest massage in normalizing blood pressure or perfusion of vital organs, and closed chest massage does generally deliver 5% to 15% of normal coronary and cerebral blood flow. The success rate for out-of-hospital resuscitation has been as high as 30% to 60% when communities are prepared to institute CPR early after a cardiac arrest. Ischemic heart disease is the most common cause of sudden death.

2. Which maneuver generally is not performed early before chest compression in basic life support outside the hospital?
A. Call for help.
B. Obtain airway.
C. Electrical cardioversion.
D. Ventilation.
Answer: C

DISCUSSION: Basic life support does involve calling for help, obtaining an airway, and beginning ventilation before starting chest compression. Electrical cardioversion requires special equipment and trained personnel and thus is part of advanced cardiac life support.

3. Which treatment would be least effective for asystole?
A. External pacemaker.
B. Intravenous epinephrine, 10 ml. of 1:10,000.
C. Intravenous calcium gluconate, 10 ml. of 10% solution.
D. Intravenous atropine, 0.5 mg.
Answer: C

DISCUSSION: Recommended treatment for asystole is administration of atropine. If atropine is unsuccessful epinephrine is given. Ultimately cardiac pacing is necessary if atropine and epinephrine do not establish an adequate heart rate. Calcium has no clear role in treating asystole.

4. The most important factor that influences the outcome of penetrating cardiac injuries is:
A. Comminuted tear of a single chamber.
B. Multiple-chamber injuries.
C. Coronary artery injury.
D. Tangential injuries.
Answer: C

DISCUSSION: Multiple studies in the literature confirm that injuries to the coronary arteries are the most important factor in determining outcome after a penetrating cardiac injury. Tangential injuries are the least serious. Injury to a single chamber—even if comminuted—or to multiple chambers is less likely to be fatal than are injuries that involve a major coronary artery.

5. The most useful incision in the operating room for patients with penetrating cardiac injury is:
A. Left anterior thoracotomy.
B. Right anterior thoracotomy.
C. Bilateral anterior thoracotomy.
D. Median sternotomy.
E. Subxyphoid.
Answer: D

DISCUSSION: The subxyphoid incision is useful for determining if there is blood in the pericardium and if there is an intracardiac injury; however, exposure is extremely limited, and definitive repair can rarely be performed through the incision. Left (or right) anterior thoracotomy is easily performed, especially in the emergency room, and gives adequate exposure to certain areas of the heart. However, each has significant limitations in exposure. Either may be extended across the thoracotomy into the other side of the chest, thus producing a bilateral anterior thoracotomy. Exposure is excellent through this incision, and most injuries can be satisfactorily repaired through this approach. Most cardiac operations today are performed through median sternotomy incisions. If the patient is in the operating room, this incision is easily performed and always provides excellent exposure for all areas of the heart.

6. In patients who present with a penetrating chest injury, injury to the heart is most likely when the following physical sign(s) is/are present:
A. Hypotension.
B. Distended neck veins.
C. Decreased heart sound.
D. All of the above.
Answer: D

DISCUSSION: Hypotension, increased venous pressure (distended neck veins), and decreased heart sounds make up the classic Beck's triad associated with cardiac tamponade. If these three findings are present in a person who has a penetrating chest wound, intracardiac injury is almost certain and operative intervention is mandatory.

7. Which of the following would be an acceptable method of repair for a neonate with symptomatic isolated coarctation of the aorta?
A. Resection with end-to-end anastomosis.
B. Prosthetic patch aortoplasty.
C. Subclavian flap aortoplasty.
D. Prosthetic tube graft repair.
Answer: AC

DISCUSSION: The most commonly used methods for coarctation repair are resection with anastomosis and subclavian flap aortoplasty. Both have been shown to provide adequate relief of the obstruction with acceptable rates of restenosis. The choice of repair depends on the patient's anatomy and the surgeon's experience. Patch aortoplasty was used frequently in the past; however, because of concern over restenosis and aneurysm formation it is no longer commonly performed. Prosthetic tube graft repair is avoided except in some complex cases and some cases of recoarctation.

8. Which of the following constitutes a true vascular ring?
A. Pulmonary artery sling.
B. Double aortic arch.
C. Anomalous origin of right subclavian artery from the descending aorta.
D. Cervical aortic arch.
Answer: B

DISCUSSION: Only the double aortic arch secondary to persistence of the right and left fourth aortic arches forms a true vascular ring. Pulmonary artery sling may cause symptoms that are due to compression of the trachea, and an anomalous right subclavian may cause dysphagia, but these anomalies do not constitute complete rings. Cervical aortic arch, which is thought to be secondary to persistence of the third aortic arch, is not a complete ring and usually is asymptomatic.

9. Which of the following may be physical examination findings in a young adult with coarctation of the aorta?
A. Posterior systolic murmur between the scapulas.
B. Diminished femoral pulses.
C. Elevated blood pressure in left arm as compared with right arm.
D. Peripheral cyanosis.
Answer: ABC

DISCUSSION: A systolic murmur that radiates posteriorly is characteristic of coarctation of the aorta. Coarctation produces obstruction to aortic flow, and thus the femoral pulse has a diminished volume with delayed upstroke. Hypertension in coarctation is multifactorial, but the most important factors are diminished renal flow (single clip, single kidney-Goldblatt model) and mechanical factors. If the right subclavian artery is anomalous and arises distal to the coarctation, blood pressure may be greater in the left arm than in the right. Isolated coarctation does not produce cyanosis.

10. In a premature infant with hyaline membrane disease and inability to be weaned from mechanical ventilation, which of the following would suggest hemodynamically significant patent ductus arteriosus (PDA)?
A. Continuous murmur.
B. Hyperactive precordium with bounding peripheral pulses.
C. Jaundice.
D. Diminished femoral pulses.
Answer: AB

DISCUSSION: PDA causes a left-to-right shunt that produces left ventricular volume overload. Physical findings include evidence of hyperdynamic circulation with a prominent apical impulse and bounding peripheral pulses. The classic murmur of PDA is a continuous or mechanical murmur heard over the precordium and radiating to the medial third of the clavicle. Diminished femoral pulses are not seen with isolated PDA and would suggest other anomalies. PDA may result in hepatomegaly but does not cause jaundice.

11. In an infant with suspected PDA, which of the following would be the optimal method of confirming the diagnosis?
A. Chest film.
B. Cardiac catheterization.
C. Retrograde aortography via an umbilical artery catheter.
D. Two-dimensional echocardiography with continuous-wave and color-flow Doppler echocardiography.
Answer: D

DISCUSSION: Echocardiography is the best method for confirming the diagnosis of a PDA. Two-dimensional echocardiography can demonstrate PDA and exclude associated anomalies. Doppler echocardiography can demonstrate the shunt, determine direction of shunting, and provide an estimate of shunt magnitude. The chest film is not particularly helpful and may be normal or show cardiomegaly with pulmonary congestion. In general, cardiac catheterization should be reserved for older patients and those with suspected associated anomalies or pulmonary hypertension.

12. Which of the following are potential complications of untreated coarctation of the aorta?
A. Endocarditis.
B. Pulmonary vascular disease.
C. Cerebrovascular accident.
D. Congestive heart failure.
Answer: ACD

DISCUSSION: Coarctation of the aorta produces an obstruction to blood flow and hypertension, turbulent flow, and increased left ventricular afterload. There is an increased incidence of coronary artery disease. Prior to the introduction of effective techniques for relief of coarctation, the most common causes of death were endocarditis, aortic rupture, congestive heart failure, and cerebrovascular accident. Pulmonary vascular disease does not occur with isolated coarctation.

13. The atrial septal defect (ASD) most commonly associated with partial anomalous pulmonary venous return (PAPVR) is:
A. Secundum defect.
B. Sinus venosus defect.
C. Ostium primum defect.
D. Complete atrioventricular (AV) canal defect.
E. Coronary sinus defect.
Answer: B

DISCUSSION: Although partial anomalous return of the pulmonary veins can occur with any of the ASDs listed, it is particularly common with sinus venosus defects and is considered by many to be part of this lesion. The most common anomaly is drainage of the right superior pulmonary vein to the lateral aspect of the superior vena cava.

14. The direction of an intracardiac shunt at the atrial level is controlled by:
A. The size of the defect
B. The compliance of the right and left ventricles.
C. The systemic oxygen saturation.
D. Right atrial pressure.
E. The presence or absence of an associated ventricular septal defect (VSD).
Answer: B

DISCUSSION: The direction of an intracardiac shunt is governed by the compliance of the downstream chambers. For an atrial level shunt, the compliance of the right and left ventricles and their ability to distend with increased volume during diastolic filling dictates the direction of the shunt flow. Since the right ventricle is usually a more compliant—and therefore more distensible—chamber than the left ventricle, flow across an ASD occurs from left to right across the open tricuspid valve during diastole. The size of an ASD does not correspond to the degree of shunt as long as the defect is large enough to be unrestrictive to flow. A large shunt can occur through a relatively small defect if the ventricular compliance is favorable.

15. The ASD most commonly associated with mitral insufficiency is:
A. Secundum defect
B. Sinus venosus defect
C. Ostium primum defect.
D. Coronary sinus defect.
Answer: C

DISCUSSION: Ostium primum defects, or “partial” AV canal defects, are commonly associated with a “cleft” of the anterior leaflet of the mitral valve. Depending on the deformity of the mitral valve, these defects can be accompanied by variable degrees of mitral insufficiency. This cleft of the mitral valve needs to be repaired at the same time that the defect is closed. Although other types of ASDs can be associated with mitral insufficiency, this is not as common. When mitral stenosis exists with a secundum ASD the condition is often referred to as Lutembacher's syndrome.

16. An electrocardiogram (ECG) in a patient with a systolic ejection murmur that shows an incomplete bundle branch block in the precordial lead is most consistent with:
A. A secundum ASD.
B. A sinus venosus ASD with PAPVR.
C. An ostium primum ASD.
D. A complete AV canal defect.
Answer: A

DISCUSSION: Many patients with secundum ASDs have an incomplete bundle branch block on their ECG. This is in contradistinction to patients with ostium primum defects, who often have a left axis deviation. Although the ECG is not pathognomonic of the defect, the findings are sometimes helpful along with other clinical and diagnostic information toward elucidating the nature of the defect.

17. ASDs can all be closed with a pericardial or prosthetic patch. Which of the following ASDs can also be safely closed primarily without the use of a patch?
A. Secundum ASD.
B. Sinus venosus ASD with PAPVR.
C. An ostium primum ASD.
D. A complete AV canal defect.
Answer: A

DISCUSSION: Secundum ASDs can frequently be closed primarily, although the use of a prosthetic or pericardial patch is indicated for large defects. The other types of ASDs are more safely closed with a patch.

18. Obstruction to pulmonary venous return is associated with which of the following anomalies?
A. Partial anomalous pulmonary venous connection (PAPVC) to the superior vena cava.
B. Infracardiac (Type III) total anomalous pulmonary venous connection (TAPVC).
C. Pulmonary vein stenosis.
D. Cor triatriatum.
E. Supracardiac (Type I) TAPVC.
Answer: BCDE

DISCUSSION: Obstruction to pulmonary venous return is the most important factor affecting circulatory function when pulmonary venous anomalies exist. This obstruction is most prevalent and severe in patients with infracardiac TAPVC, but it also occurs in as many as 50% of patients with supracardiac TAPVC and 20% of patients with intracardiac TAPVC to the coronary sinus. Obstruction to pulmonary venous return is also the primary pathophysiologic effect of both pulmonary vein stenosis and cor triatriatum. Obstruction, however, is rare with partial anomalous pulmonary venous connection, especially with the common form of PAPVC to the superior vena cava.

19. Postoperative complications associated with repair of TAPVC include:
A. Complete heart block.
B. Acute pulmonary hypertensive crisis.
C. Pleural effusions.
D. Pulmonary venous obstruction.
Answer: BD

DISCUSSION: In the early postoperative period after repair of obstructed forms of TAPVC, acute episodes of pulmonary hypertension may develop as a response to stress. To minimize this potentially fatal complication, infants are kept anesthetized with fentanyl and pancuronium for at least 48 hours. Residual or recurrent pulmonary venous obstruction occurs in only 5% to 10% of patients after TAPVC repair, but if identified it requires early reoperation. Reoperation is usually successful if the obstruction is at the level of the anastomosis. Unfortunately, in some cases, the obstruction is in the pulmonary veins and surgical relief is less successful. Although complete heart block and pleural effusions can occur after any cardiac operation, they rarely occur after TAPVC repair.

20. Which of the following statements about VSDs is/are correct?
A. Perimembranous lesions are located in the region of the membranous portion of the interventricular septum near the anteroseptal commissure of the tricuspid valve.
B. Muscular VSDs are holes in the interventricular septum that are bordered by muscle on three sides and by the pulmonary and the aortic valve annulus superiorly.
C. VSD, in its isolated form, is the most commonly recognized congenital heart defect.
D. The conduction bundle runs along the posteroinferior rim of a perimembranous VSD.
Answer: ACD

DISCUSSION: Perimembranous VSDs occupy the area of the membranous portion of the interventricular septum adjacent to the anteroseptal commissure of the tricuspid valve. Often a remnant of the membranous portion of the interventricular septum (the membranous flap) is left hanging on the posteroinferior rim of the defect. The annulus of the tricuspid and aortic valves often form a part of the rim of the defect, but in some patients they are separated from the VSD by a thin rim of muscle tissue that protects the conduction bundle. Muscular VSDs have exclusively muscular rims on all four sides. VSDs in the outlet septum that extend to the annuluses of the aortic and pulmonary valves are called doubly committed or juxta-arterial defects. Isolated VSDs occur at an approximate rate of 2 per 1000 live births and represent 30% to 40% of all congenital heart malformations at birth. The conduction bundle in patients with perimembranous VSDs does run along the posteroinferior rim of the defect on the left ventricular side. Sutures used for repair of a perimembranous VSD should be placed well away from this area to avoid the creation of surgically induced complete heart block.

21. Which of the following statements about VSDs is/are true?
A. When coarctation of the aorta is associated with VSD, it most commonly occurs in infants with large lesions who have to undergo repair before age 3 months.
B. In some patients with VSD, aortic valve incompetence develops over time and progresses.
C. In the United States doubly committed or juxta-arterial VSDs are most commonly associated with aortic insufficiency.
D. PDA is present in approximately one fourth of infants with a VSD and concomitant congestive heart failure.
Answer: ABD

DISCUSSION: VSD in combination with severe coarctation of the aorta occurs in approximately 17% of patients. This combination is more common among infants with large VSDs undergoing operation before age 3 months. Aortic valve incompetence does develop over time in some patients with VSD, presumably as a result of progressive prolapse of the right aortic cusp through the defect. In the United States two thirds of patients with VSD and aortic insufficiency have perimembranous lesions and one third have a doubly committed or juxta-arterial lesion. In Japan, however, the reverse is true: two thirds have doubly committed or juxta-arterial lesions and one third have perimembranous lesions. A moderate- or large-sized PDA is associated with VSD in approximately 6% of patients of all ages; however, in infants with VSD and concomitant congestive heart failure, PDA is present in approximately 25%.

22. Which of the following statements about VSD is/are correct?
A. A large VSD is approximately the size of the pulmonary valve orifice or larger.
B. Large VSDs associated with high pulmonary blood flow result in an enlarged left atrium on chest x-ray.
C. Patients with small (restrictive) VSDs tend to have normal right ventricular and pulmonary arterial pressures with normal pulmonary vascular resistance and no evidence of pulmonary vascular disease.
D. A pulmonary vascular resistance greater than 10 to 12 units per sq. m. is considered a contraindication to operation.
Answer: BCD

DISCUSSION: A large VSD is approximately the size of the aortic valve orifice or larger and causes systemic right ventricular systolic pressures. In the absence of right ventricular outflow tract obstruction, the pulmonary artery systolic pressure will also be systemic in the presence of a large VSD. Large VSDs associated with a high pulmonary blood flow do result in an enlarged left atrium because of increased pulmonary venous return. When marked enlargement of the left atrium is present in a patient suspected of having a VSD, the presence of coexisting mitral valve regurgitation should also be considered. Patients with small VSDs do have normal right ventricular and pulmonary arterial pressures. There is only a slight elevation of pulmonary blood flow relative to the systemic flow, and the pulmonary vascular resistance is normal without evidence of pulmonary vascular disease. At any age, the presence of pulmonary vascular disease so severe that the pulmonary vascular resistance is fixed and greater than 10 to 12 units per sq. m. is considered a contraindication to operation.

23. Which of the following statements about VSDs is/are correct?
A. Spontaneous closure of VSDs occurs in 25% to 50% of patients during childhood.
B. Tachypnea and failure to thrive are symptoms frequently associated with large VSDs.
C. Patients with normal pulmonary vascular resistance and left-to-right shunting across the VSD have Eisenmenger's complex.
D. Patients with a large VSD and low pulmonary vascular resistance can present with a middiastolic murmur at the apex.
Answer: ABD

DISCUSSION: Spontaneous and complete closure of VSDs, even large ones, has been estimated to occur in 25% to 50% of patients during childhood. The probability of eventual spontaneous closure is inversely related to the age at which the patient is observed. Tachypnea, poor feeding, growth failure, recurrent respiratory infections, exercise intolerance, and severe cardiac failure may develop in patients with large VSDs. Patients with Eisenmenger's complex are cyanotic, polycythemic, and severely limited in their exercise tolerance, owing to markedly elevated pulmonary vascular resistance associated with a predominantly right-to-left shunt across the VSD. A middiastolic murmur can be present at the apex in patients with a large VSD associated with low pulmonary vascular resistance. This indicates high pulmonary blood flow with a large flow across the mitral valve into the left ventricle.

24. Which of the following is/are true of the surgical treatment of VSDs?
A. A right ventricular approach is employed for the repair of most perimembranous VSDs.
B. Intracardiac repair is advisable for patients with intractable symptoms and for asymptomatic infants with evidence of increasing pulmonary vascular resistance.
C. Complete heart block is a common complication.
D. Hospital mortality after repair of VSD in infants approaches 20%.
Answer: B

DISCUSSION: The right atrial approach is preferred for the repair of most perimembranous VSDs. Prompt intracardiac repair is indicated for infants with large defects, large shunts, and pulmonary hypertension who present with intractable left ventricular failure, recurrent pulmonary infections, severe growth failure, or evidence of increasing pulmonary vascular resistance. In the modern era, complete heart block requiring a permanent pacemaker is a very uncommon complication of surgical closure of a ventricular septal defect. Hospital mortality after closure of a VSD currently approaches zero. While in earlier years younger age was an incremental risk factor for hospital death in some surgical experiences, this risk has been neutralized during the past decade.

25. Tetralogy of Fallot consists of all of the following features except:
A. ASD.
B. VSD.
C. Dextroposition of the aorta.
D. Pulmonary stenosis.
E. Right ventricular hypertrophy.
Answer: A

DISCUSSION: Although ASD is a frequent component of tetralogy of Fallot, it was not included by Fallot as part of his classic tetralogy. Occasionally, the inclusion of an ASD prompts use of the term pentalogy of Fallot. The other four anomalies listed were all mentioned by Fallot in his original description of this defect.

26. Which of the following has the greatest impact on the physiology of tetralogy of Fallot?
A. The size of the ASD.
B. The size of the VSD.
C. The degree of pulmonary stenosis.
D. The amount of aortic overriding.
Answer: C

DISCUSSION: The VSD in tetralogy of Fallot is nonrestrictive, and therefore its size does not affect the degree of shunting that can occur. Likewise, an ASD, which may or may not be a component of tetralogy of Fallot, can provide right-to-left shunting at the atrial level but is not the main contributor to the cyanosis of this disease. The degree of right-to-left shunt across the VSD is dictated by the variable compliance of the downstream chambers, and the increased resistance imposed by severe pulmonary stenosis creates greater amounts of right-to-left shunting and, therefore, more intense cyanosis. The position of the aorta in relation to the VSD is not important as long as no subaortic obstruction exists.

27. Which of the following anomalies is not associated with tetralogy of Fallot?
A. Absence of the left pulmonary artery.
B. A right aortic arch.
C. A retroesophageal subclavian artery.
D. Anomalous origin of the left anterior descending coronary artery from the right coronary artery.
E. Primary pulmonary hypertension.
Answer: E

DISCUSSION: The first four defects listed occasionally are associated with tetralogy of Fallot. A right aortic arch is seen in 25% of patients with that lesion. Anomalous coronary arteries or a retroesophageal subclavian artery are found in as many as 5% to 10% of patients. Absence of a pulmonary artery is unusual but can present in as many as 3% of patients. Pulmonary hypertension is distinctly unusual with tetralogy of Fallot unless the patient has had excessive pulmonary blood flow from collaterals or systemic-to-pulmonary artery shunts for a long time. It is because these patients usually do not have pulmonary hypertension that infant correction with transannular patches can be performed with such great success.

28. Surgical treatment of a patient with tetralogy of Fallot can include any of the following except:
A. Maintenance of ductal patency with prostaglandins (PGE 1) to provide pulmonary blood flow while the baby is transferred to an institution equipped to provide more definitive therapy.
B. Banding of the pulmonary artery in an acyanotic patient with tetralogy of Fallot to control pulmonary blood flow and prevent the development of pulmonary hypertension.
C. Placement of a subclavian-to-pulmonary artery shunt on the side opposite the aortic arch in a 3-day-old infant with severe cyanosis.
D. Closure of the VSD and transannular patching of the right ventricle onto the main pulmonary artery in a 2-day-old infant.
Answer: B

DISCUSSION: Patients with tetralogy of Fallot who do not appear cyanotic still have mild arterial hypoxemia by arterial blood gas determination. Patients with tetralogy of Fallot rarely have excessive pulmonary blood flow, and the development of pulmonary hypertension is not a concern in this population. Banding of the pulmonary artery is never a consideration in patients with tetralogy of Fallot, since the predominant physiologic effect of the defect results from too little pulmonary blood flow to begin with. Acyanotic patients with tetralogy of Fallot (“pink tets”) can usually be followed for several months and their defects repaired electively as a first-stage procedure (usually by age 6 months). All of the other therapies are appropriate treatment for babies with tetralogy of Fallot. Prostaglandins maintain patency of the ductus arteriosus, providing an anatomic systemic-to-pulmonary artery shunt that sustains pulmonary blood flow until a more permanent surgical solution can be provided. The advent of prostaglandin therapy has enabled numerous critically ill infants to become stabilized enough to reach a tertiary care institution and receive proper surgical therapy who might not otherwise have survived had it not been for the ability of pulmonary blood flow to be maintained through the reversal of duct closing. The choice of palliative shunting or total anatomic correction rests largely with the experience and skill of the surgical team and is dictated in part by the anatomy of the pulmonary arteries. Either of these options is acceptable.

29. The predominant determinant of outcome for patients with pulmonary atresia and an intact ventricular septum revolves around:
A. The size of the ASD.
B. The baby's age at presentation.
C. The size of the right ventricular cavity and tricuspid valve.
D. The presence of a tricuspid—as opposed to a bicuspid—pulmonary valve.
E. The level of hypoxemia at presentation.
Answer: C

DISCUSSION: The long-term outcome for babies with pulmonary atresia and intact ventricular septum depends on the ability to convert the cardiac circulation into a two-ventricle versus one-ventricle physiology. Patients with a good-sized right ventricle and tricuspid valve can often be treated with pulmonary valvotomy or right ventricular outflow patching alone and can have a fairly acceptable outcome. Patients with a small right ventricle that cannot provide adequate pumping to the pulmonary bed and is often associated with a small tricuspid valve annulus may need to be staged toward a Fontan procedure—and, consequently, a less acceptable outcome. The size of an ASD is not relevant except that in patients with this syndrome, the right side of the heart will decompress across the ASD until antegrade flow can be established. Therefore, an ASD in some part is an essential feature of this lesion. The degree of arterial hypoxemia, the nature of the pulmonary valve, and the patient's age at presentation may all be factors that relate to clinical management, but they do not imply specific consequences with respect to long-term outcome.

30. Which of the following statements about double-outlet right ventricle are true?
A. A VSD is usually present.
B. In the Taussig-Bing type of double-outlet right ventricle, the VSD is usually noncommitted.
C. Patients with double-outlet right ventricle and a subaortic VSD usually have pulmonary stenosis.
D. Patients with double-outlet right ventricle with a subpulmonary VSD (Taussig-Bing malformation) tend to mimic patients with transposition of the great arteries and VSD in their presentation and natural history.
Answer: ACD

DISCUSSION: A VSD is usually present in patients with double-outlet right ventricle and is the only outlet from the left ventricle. Both great arteries may arise totally from the right ventricle, or one or both may overlie the ventricular septum immediately above the VSD. To categorize the heart as having a double-outlet right ventricle, more than 50% of each great artery must arise from the right ventricle. In the Taussig-Bing type of double-outlet right ventricle, the VSD is related to the pulmonary valve annulus and is termed a subpulmonary defect. Additional morphologic characteristics peculiar to this entity have been described. Most patients with double-outlet right ventricle and a subaortic VSD have concomitant pulmonary stenosis that protects the lungs from pulmonary vascular disease and also results in a clinical course similar to that of patients with tetralogy of Fallot. In the absence of pulmonary stenosis the presentation, clinical course, and natural history of the Taussig-Bing malformation are similar to those of transposition of the great arteries with VSD. Cyanosis is present, usually from birth, since streaming directs the desaturated systemic venous return toward the aorta and the oxygenated left ventricular blood toward the pulmonary artery. These patients tend to develop early congestive heart failure and can develop severe pulmonary vascular disease early in life. They usually experience symptoms within the first few months of life.

31. Which of the following statements about the surgical repair of double-outlet right ventricle are true?
A. In double-outlet right ventricle with a subaortic or doubly committed VSD, a tunnel-type repair connecting a committed VSD with its respective great artery is usually employed.
B. Repair of the Taussig-Bing malformation can be accomplished using an intraventricular tunnel technique or by performing a straight patch closure of the VSD combined with an arterial switch procedure.
C. The hospital mortality rate is highest when a subaortic VSD is present.
D. Some hearts with double-outlet right ventricle and a noncommitted VSD must be repaired using a modification of the Fontan procedure.
Answer: ABD

DISCUSSION: When the VSD is subaortic or doubly committed, the tunnel-type repair connects the left ventricle via the VSD and tunnel to the aorta. The Taussig-Bing malformation can be repaired using an intraventricular tunnel technique described by Kawashima. This repair can best be accomplished when the great arteries are in a more or less side-by-side relationship with the aorta to the right of the pulmonary artery. The infundibular septum is generously resected and the VSD is connected to the aorta by an intraventricular tunnel that runs posterior to the pulmonary artery. The most common approach for the repair of the Taussig-Bing malformation involves patch closure of the VSD to the pulmonary artery. This creates transposition of the great arteries with an intact interventricular septum. An arterial switch procedure then establishes ventriculoarterial concordance. Of all the types of double-outlet right ventricle the hospital mortality is lowest when a subaortic or doubly committed VSD is present. Double-outlet right ventricle is associated with a noncommitted VSD in approximately 10% of patients in surgical series. The repair of this subset of patients is associated with a relatively high mortality, as compared with the results obtained after repair of other forms of double-outlet right ventricle. At times, because of the remote location of the VSD and because of other compelling anatomic features, complete repair cannot be performed. In this case, a modification of the Fontan procedure must be employed.

32. Management of a patient with tricuspid atresia within the first month of life may include:
A. Creation of a systemic artery–to–pulmonary artery shunt.
B. Observation.
C. Creation of a bidirectional superior cavopulmonary anastomosis.
D. Pulmonary artery banding.
E. Fontan procedure.
Answer: ABD

DISCUSSION: Initial management of newborn infants with tricuspid atresia is determined by the anatomic and physiologic factors that affect the balance of pulmonary and systemic blood flow. Infants with severely limited pulmonary blood flow and arterial oxygen saturations of less than 70% should be stabilized with PGE 1 to maintain patency of the ductus arteriosus until a systemic-to-pulmonary artery shunt can be performed. Patients with unobstructed pulmonary blood flow may exhibit only mild cyanosis but suffer from significant congestive heart failure. Many of these patients are best managed by pulmonary artery banding to decrease the volume overload on the left ventricle and to prevent the early development of irreversible pulmonary vascular disease. Some patients with moderate restriction of pulmonary blood flow may have balanced delivery of blood to the systemic and the pulmonary circulation. These patients can be carefully followed until such time as an imbalance develops or they become candidates for a bidirectional superior cavopulmonary (Glenn) anastomosis or a Fontan procedure. The normally high pulmonary vascular resistance present in the first month of life precludes the performance of either the Glenn or the Fontan procedure in the newborn.

33. Which of the following should contraindicate performance of the Fontan procedure?
A. Patient age of 25 years.
B. Severe mitral insufficiency.
C. Left ventricular end-diastolic pressure of 18 mm. Hg.
D. Right pulmonary artery stenosis.
E. Pulmonary vascular resistance of 6 Woods units.
Answer: CE

DISCUSSION: Good ventricular function and low pulmonary vascular resistance are essential requirements for a successful Fontan procedure. The Fontan operation should not be performed when ventricular ejection fraction is less than 30% or ventricular end-diastolic pressure is greater than 15 mm. Hg. Pulmonary vascular resistance in excess of 4 Woods units should also be considered an absolute contraindication for Fontan correction. Age at the time of Fontan procedure does not appear to be a major risk factor, except before age 2 years. Although patients who have survived into the third or fourth decade are likely to have ventricular dysfunction, a Fontan procedure can be performed successfully in these older patients if ventricular function and pulmonary vascular resistance meet the above criteria. In patients with tricuspid atresia a competent mitral valve is important for satisfactory cardiac output after the Fontan procedure. The presence of severe mitral insufficiency, however, should not necessarily contraindicate the procedure. In these cases it is recommended that the mitral valve be repaired or replaced in combination with the creation of a bidirectional superior cavopulmonary anastomosis. A completion Fontan operation is performed later. Distorted or stenosed pulmonary arteries are common sequelae of systemic-to-pulmonary artery shunts and may result in unsatisfactorily high pulmonary vascular resistance. In most cases, these stenoses can be repaired at the time of Fontan correction or with a bidirectional superior cavopulmonary anastomosis.

34. Initial management of a newborn infant with hypoplastic left heart syndrome should include:
A. Intravenous administration of PGE 1.
B. Supplemental oxygen.
C. Routine intubation and mechanical ventilation to achieve a PCO 2 between 30 and 35 mm. Hg.
D. Cardiac catheterization and balloon atrial septostomy.
Answer: A

DISCUSSION: Postnatal stabilization of infants with hypoplastic left heart syndrome requires patency of the ductus arteriosus and balance of the systemic and the pulmonary circulation. Because the ductus is the only pathway from the right ventricle to the systemic circulation, duct patency must be maintained with intravenous PGE 1. To minimize the workload on the single ventricle and ensure adequate delivery of oxygen to the tissues, an equal delivery of blood to both the lungs and the body is sought. The normal postnatal decrease in pulmonary vascular resistance often results in overperfusion of the pulmonary circulation and underperfusion of the systemic circulation. Maneuvers that further decrease pulmonary vascular resistance, such as the addition of supplemental oxygen, lowering the PCO 2 to less than 35 mm. Hg, or eliminating any resistance at the atrial septum by balloon septostomy only worsens the imbalance.

35. The performance of a bidirectional superior cavopulmonary (Glenn) anastomosis as the second stage in the reconstructive approach to hypoplastic left heart syndrome:
A. Provides early relief of volume load on the single right ventricle.
B. Increases peripheral oxygen saturations to greater than 90%.
C. Permits concomitant repair of pulmonary artery or aortic arch stenoses.
D. Improves mortality and morbidity of subsequent Fontan procedure.
Answer: ACD

DISCUSSION: After the first-stage reconstructive (Norwood) procedure, the circulation is inherently inefficient because of the obligatory recirculation of a portion of both saturated and desaturated blood. Closure of the arterial shunt and creation of a bidirectional Glenn anastomosis eliminates this inefficient recirculation and significantly diminishes the volume load on the single right ventricle. Distorted and stenosed central pulmonary arteries or aortic arch obstructions should be repaired at the same time the bidirectional Glenn procedure is performed. In almost all series the mortality of the Fontan procedure has decreased since the adoption of the three-stage approach for hypoplastic left heart syndrome. Because systemic and pulmonary venous blood continue to mix in the right atrium after a bidirectional Glenn procedure, cyanosis persists with peripheral oxygen saturations between 75% and 85%.

36. Which of the following statements about truncus arteriosus are true?
A. Most infants survive without operations until late childhood.
B. Most infants present with cyanosis.
C. Most infants present with congestive heart failure.
D. Repair requires a conduit from right ventricle to pulmonary arteries.
Answer: BCD

DISCUSSION: While an occasional child survives to age 3 or 4 years, without either palliative or totally corrective surgical treatment few live past early infancy. The lesion is one of excessive pulmonary blood flow because of the origin of the pulmonary arteries from the truncus arteriosus; physiologically, the pulmonary arteries arise directly from the aorta. Although the aortic saturation can never be 100% because of some element of bidirectional shunting at the VSD, the physiologic manifestations are congestive heart failure and excessive pulmonary blood flow rather than cyanosis. The congestive heart failure becomes severe as pulmonary vascular resistance drops. If congestive heart failure later improves spontaneously, it is because of the development of pulmonary vascular disease. Complete repair always requires closure of the VSD, detachment of the pulmonary arteries from the common trunk, and re-establishment of an outflow tract from the right ventricle to the pulmonary artery. This conduit usually contains a valve and can be either a homograft or a synthetic conduit containing a porcine valve.

37. Truncus arteriosus is a diagnosis with anatomic components including:
A. VSD.
B. Abnormal origin of pulmonary arteries.
C. Subaortic stenosis.
D. Single ventricular outflow valve.
Answer: ABD

DISCUSSION: By definition, a VSD is always present immediately beneath the truncal valve. The pulmonary arteries arise abnormally from the single trunk, which is due to failed partitioning of the embryonic conus during the first few weeks of fetal development. In the classification of Collett and Edwards, Type I truncus arteriosus has a single arterial trunk giving rise to an aorta and a main pulmonary artery; in Type II the right pulmonary arteries arise immediately adjacent to one another from the dorsal wall of the truncus; in Type III the right and left pulmonary arteries originate from either side of the truncus; and in Type IV the proximal pulmonary arteries are absent and pulmonary blood flow is by way of major aortopulmonary atresia and is no longer considered truncus arteriosus. Subaortic stenosis cannot occur in this anomaly. The single ventricular outflow valve is the truncal valve. It may contain from two to six cusps, but most often there are three and, next most often, four.

38. Optimal treatment for the neonate who presents with transposition of the great arteries {S,D,D}* and intact ventricular septum includes:
A. PGE 1 infusion to maintain duct patency.
B. Administration of intravenous fluid to increase intravascular volume.
C. Hyperventilation to decrease pulmonary resistance.
D. Oxygen administration to increase arterial oxygen tension.
E. Atrial balloon septostomy to improve atrial mixing.
Answer: ABE

DISCUSSION: Because with transposition of the great vessels the systemic and the pulmonary circulations exist in parallel rather than in series, survival depends on mixing between pulmonary and systemic circulations. Initially infants with transposition and intact atrial septum survive because of aortopulmonary flow through PDA, which may be maintained with prostaglandin infusions. Although increased pulmonary flow may cause enlargement of the left atrium and stretching of the foramen ovale resulting in atrial-level mixing of oxygenated and nonoxygenated blood, inadequate mixing at the atrial level will result in marginal tissue oxygenation, which does not improve with oxygen administration. Atrial balloon septotomy results in improved admixture and oxygen delivery in these patients and should be performed promptly if peripheral acidemia and severe cyanosis are present. Relative dehydration may decrease the degree of interatrial shunting and volume infusion often improves hemodynamics in infants. Decreased pulmonary vascular resistance may increase pulmonary blood flow at the expense of systemic blood flow and alter the loading conditions of the left ventricle, which may complicate early arterial repair.

39. Factors that preclude the use of a single-stage arterial switch reconstruction of dextrotransposition of the great vessels include:
A. Age older than 6 weeks with a left ventricular pressure of less than 50% of systemic pressure.
B. Dynamic left ventricular outflow tract obstruction.
C. Intramural coronary artery anatomy.
D. Valvar pulmonic stenosis.
E. Subpulmonary VSD.
Answer: AD

DISCUSSION: Single-stage arterial switch procedure for reconstruction of transposition of the great vessels, with or without associated VSD has become the standard of treatment in the majority of cardiac centers. Contraindications to arterial switch repair include fixed types of left ventricular outflow tract obstruction, including valvar pulmonic stenosis, which would render the systemic semilunar valve stenotic or incompetent. Anatomic abnormalities without stenosis, such as a bicuspid valve, however, are suitable for surgical correction. The location of VSD does not affect surgical outcome, and most VSDs can be approached adequately through the right atrium or the anterior great vessel. Most dynamic forms of left ventricular outflow tract obstruction are often relieved partially or completely by realignment of the ventricular septum with the hemodynamic changes following successful arterial switch repair. When, however, the left ventricle has not been prepared to sustain the pressure load of the systemic circulation by the decrease in pulmonary vascular resistance that occurs in the first few weeks of life and when the ventricular pressure is less than 50% of the systemic ventricular pressure, one-stage repair is contraindicated, and staged repair with pulmonary banding and shunt followed by arterial switch must be contemplated.

40. Complications commonly associated with the atrial (Senning and Mustard) repairs of transposition of the great arteries include:
A. Atrial arrhythmias.
B. Systemic or pulmonary venous obstruction.
C. Right ventricular outflow tract obstruction.
D. Systemic ventricular failure.
E. Progressive elevation of pulmonary vascular resistance.
Answer: ABD

DISCUSSION: The atrial repair of transposition of the great arteries—rerouting systemic and pulmonary venous blood at the atrial level—results in the right ventricle's becoming the systemic ventricle. This results in an anatomic right ventricle with abnormal geometry sustaining the afterload of a more ideally suited left ventricle. Long-term complications of ventricular dilatation, AV valve regurgitation, and right ventricular failure have been reported in as many as 10% of patients many years following the atrial operation. The multiple suture lines in the atrium have been associated with a high incidence of late atrial arrhythmias and a low incidence of sinus rhythm following the Mustard and Senning operations. These complications do not appear to be as frequent with the arterial switch repair. In addition, the complicated interatrial baffles have been associated with pulmonary or systemic venous baffle obstruction. Because the right ventricular outflow tract is not addressed during an atrial switch operation, right ventricular outflow tract obstruction is not a recognized complication following the repair. Right ventricular outflow tract and supravalvar pulmonic stenosis, however, have been reported in patients after the arterial switch repair, owing to the reconstruction of the right ventricular outflow tract in that operation. Although progression of pulmonary arterial obstruction has rarely been reported following early repair with the atrial or the arterial switch procedure, it is an unusual complication if operation is undertaken in infancy. Delayed repair beyond age 6 months to 1 year, however, has been associated with a higher incidence of progressive development of pulmonary vascular obstructive disease. The rapidity of the development of pulmonary vascular disease is increased by the coexistence of a VSD.

41. Critical aortic stenosis in the neonate is characterized by which of the following?
A. It is most often due to commissural fusion of a trileaflet valve.
B. It may be associated with coarctation of the aorta, PDA, and mitral stenosis.
C. It can be managed medically until the child is large enough to undergo aortic valve replacement.
D. Success of valvotomy is determined by the adequacy of the left ventricle.
Answer: BD

DISCUSSION: Critical aortic stenosis in the neonate most often presents in the first week of life with severe and progressive congestive heart failure and may be associated with coarctation of the aorta, PDA, and mitral stenosis. The prognosis is poor unless valvotomy can be performed expeditiously. Medical management cannot stabilize these infants for valve replacement at a later age. Infants whose left ventricle is too small to sustain the systemic circulation are unlikely to survive aortic valvotomy and, thus, should be managed as patients with hypoplastic left heart syndrome. The aortic valve in neonatal aortic stenosis is most commonly unicuspid or bicuspid.

42. Surgical management of aortic valve disease in an older child may include:
A. Enlargement of the aortic annulus.
B. Incision of fused commissures.
C. Insertion of a porcine valve prosthesis.
D. Transfer of the pulmonary valve to the aortic position.
Answer: ABD

DISCUSSION: The majority of older children with aortic stenosis and significant transvalvular gradients can be treated successfully by aortic valvotomy. This can be done percutaneously with balloon dilatation or surgically with direct visualization of the aortic valve and incision of the fused commissures. Aortic valve replacement is rarely necessary as a primary procedure but may be required in children who develop progressive aortic insufficiency after a previous intervention. When valve replacement is performed it is desirable to insert the largest prosthesis possible, to allow for growth. Enlargement of the aortic annulus is commonly performed for this purpose. If a true valve prosthesis is employed, a mechanical valve is preferred. Durability of xenograft valves in children is limited owing to early calcification and leaflet degeneration. The pulmonary autograft technique may be the best method of aortic valve replacement in children. With this operation the patient's own pulmonary valve is transferred to the aortic position and a pulmonary allograft is inserted to replace the pulmonary valve. Although the pulmonary autograft may not achieve the long-term durability of a mechanical valve, the patient does not face the long-term complications of thromboembolism and bleeding imposed by a mechanical valve and lifelong anticoagulation.

43. Which of the following statements about subvalvular aortic stenosis are true?
A. Most patients present in early infancy with severe congestive heart failure.
B. An ejection click is a specific physical sign of subaortic stenosis.
C. The subaortic membrane is approached surgically via the aorta and aortic valve.
D. A concomitant septal myectomy decreases the incidence of recurrent subaortic stenosis.
Answer: CD

DISCUSSION: Subaortic stenosis is rarely encountered in neonates. Most often it is discovered in an asymptomatic child during a routine physical examination. A loud crescendo–decrescendo systolic murmur without an ejection click is usually noted. The presence of an ejection click is more consistent with isolated valvular aortic stenosis. Discrete subaortic stenosis is approached surgically with cardiopulmonary bypass, aortic cross-clamping, and cardioplegic arrest. The aorta is opened and the aortic valve leaflets are retracted, exposing the fibrous membrane. The fibrous ring is carefully excised, taking care to avoid injury to the anterior leaflet of the mitral valve and the penetrating conduction bundle. Once the subaortic membrane is excised a septal myectomy further opens the left ventricular outflow tract and diminishes the likelihood of recurrent subaortic stenosis.

44. Management of hypertrophic obstructive cardiomyopathy may include:
A. Propranolol and verapamil.
B. Aortic valve replacement.
C. Dual-chamber sequential pacing.
D. Combined septal myectomy and mitral valve plication.
Answer: ACD

DISCUSSION: The majority of patients with hypertrophic obstructive cardiomyopathy are treated medically with beta-blockers such as propranolol and calcium channel blockers such as verapamil. Patients whose symptoms do not respond to medical therapy are treated surgically with a transaortic septal myectomy. Recent reports indicate that simple plication of the anterior leaflet of the mitral valve performed in addition to the septal myectomy further opens the left ventricular outflow tract by eliminating systolic anterior motion of the mitral valve. Aortic valve replacement is not an appropriate treatment for hypertrophic obstructive cardiomyopathy. Some patients who are poor surgical candidates may experience relief of symptoms and left ventricular outflow gradients with dual-chamber permanent pacing. Appropriate pre-excitation of the ventricular septum can prompt the septum to move away from the left ventricular wall during systole and open the outflow tract.

45. Which of the following statements about supravalvular aortic stenosis are true?
A. Surgical repair is indicated only when the systolic gradient exceeds 75 mm. Hg.
B. Simple excision of the supravalvular membrane results in satisfactory relief of the stenosis in most patients.
C. The diffuse form of supravalvular aortic stenosis may cause obstruction to branches of the aortic arch.
D. Reoperation after repair of discrete supravalvular aortic stenosis is rare unless abnormalities of the valve itself also exist.
Answer: CD

DISCUSSION: Supravalvular aortic stenosis is a progressive disease and should be repaired surgically if symptoms are present or the systolic gradient exceeds 50 mm. Hg. In addition to excision of the supravalvular membrane, a patch of dacron or pericardium must be placed across the area of narrowing and down into at least one of the sinuses of Valsalva. Reoperation is rare after this procedure unless associated aortic valve disease is also present. In the diffuse form of the disease the thickening of the aortic wall commonly results in significant luminal narrowing of the ascending aorta and its major branches.

46. Each year the approximate number of Americans who die from complications of coronary artery disease is:
A. 100,000.
B. 250,000.
C. 500,000.
D. 1,000,000.
E. Over 2,000,000.
Answer: C

DISCUSSION: It is estimated that approximately 7,000,000 Americans currently have symptomatic coronary artery disease. Of these some 1,500,000 experience myocardial infarction annually and approximately 500,000 die each year from complications.

47. Which of the following arteries is most likely to be involved with serious atherosclerosis?
A. The right coronary artery.
B. The left coronary artery.
C. The anterior descending coronary artery.
D. The circumflex coronary artery.
Answer: C

DISCUSSION: In order of frequency, the anterior descending coronary artery is the most commonly involved with atherosclerosis, followed by the right coronary, the circumflex, and the left main coronary artery.

48. Which of the following statements about collaterals in the normal coronary circulation is true?
A. There is a rich and quite effective collateral circulation in the coronary arterial bed.
B. The coronary arterial bed has minimal effective collaterals.
C. The coronary arterial bed is an absolute example of anatomic end-arteries.
Answer: B

DISCUSSION: The collateral circulation to the heart is relatively poor. In the human heart there are few natural collaterals of sufficient diameter for delivery of a significant quantity of blood. Most of the collaterals are approximately 200 mm. or smaller, and channels of this size cannot conduct significant quantities of blood for cardiac requirements. There is no absolute example of anatomic end-arteries in humans. While the magnitude of arterial collateral circulation varies considerably, all organs have some collaterals.

49. If blood entering the normal arterial circulation of the heart is 100% saturated with oxygen, oxygen saturation of blood in the coronary sinus can be expected to be approximately:
A. 75%.
B. 60%.
C. 50%.
D. 35%.
E. Less than 20%.
Answer: D

DISCUSSION: The heart has an unusually high rate of oxygen utilization and consumes approximately two thirds of the oxygen in the arterial blood. The oxygen saturation of the blood in the coronary sinus is usually about 30% to 35% and varies with the magnitude of cardiac disease. The body as a whole extracts approximately 25% of the oxygen it receives, thus emphasizing the great need of the heart for oxygen at rest as well as at exercise.

50. Coronary bypass procedures have been demonstrated to:
A. Reduce the incidence of myocardial infarction.
B. Significantly relieves angina symptoms.
C. Statistically improve the life span.
D. Improve the ejection fraction of the left ventricle in many patients in whom it is significantly depressed preoperatively.
Answer: ABCD

DISCUSSION: In a variety of studies, coronary bypass procedures have been demonstrated to reduce the incidence of subsequent myocardial infarction as well as to relieve significantly anginal symptoms. They also improve the life span of most patients as well as the ejection fraction of the left ventricle in those in whom it was depressed preoperatively.

51. The following patients are best treated with coronary artery bypass grafting (CABG):
A. A 60-year-old man with class II angina, 75% proximal right coronary artery lesion, and normal ventricular function.
B. A 60-year-old man with unstable angina, three-vessel disease, and an ejection fraction of 35%.
C. A 60-year-old nondiabetic man with class III angina symptoms and focal discrete lesions in the mid-right coronary artery and mid-left circumflex artery.
D. A 60-year-old man with diabetes, class IV angina, 75% proximal left anterior descending and 75% proximal right coronary artery obstruction, and left ventricular ejection fraction of 60%.
Answer: BD

DISCUSSION: CABG has been shown to prolong patient survival compared with medical therapy in those patients with left main occlusive disease and those with three-vessel or two-vessel disease with proximal left anterior descending involvement in association with class III or greater anginal symptoms, impaired ejection fraction, or easily inducible ischemia with exercise. Although percutaneous transluminal coronary angioplasty (PTCA) appears to be comparable to CABG in nondiabetic patients, patients with diabetes appear to have a significant survival advantage when CABG is used. Similarly, patients with more extensive coronary artery disease are better treated with CABG than with PTCA.

52. Sternal wound infections that spread to the mediastinum are associated with a mortality rate of:
A. 60%.
B. 30%.
C. 25%.
D. Less than 15%.
Answer: D

DISCUSSION: Although the mortality rate following sternal infections with mediastinitis formerly was high, it is now greatly reduced. In most series, mediastinitis is cured in more than 90% of patients who are treated aggressively with débridement and placement of muscle flaps or omentum into the mediastinum to speed wound healing.

53. Perioperative myocardial infarction occurs following coronary bypass procedures in approximately:
A. 15%.
B. 10%.
C. 7%.
D. Less than 5%.
Answer: D

DISCUSSION: Following improvements in myocardial protection and coronary grafting techniques, perioperative myocardial infarction now occurs in less that 2% to 4% of patients in most series.

54. Following acute myocardial infarction, ventricular septal defects occur in:
A. 20%.
B. 10%.
C. 15%
D. 2% or less.
Answer: D

DISCUSSION: Postmortem studies indicate that 8% to 10% of fatal cases of myocardial infarction are due to rupture of the heart. In addition, infarction of the interventricular septum with subsequent formation of a ventricular septal defect occurs in 1% to 2% of patients with acute myocardial infarction. The usual interval between the acute infarction and septal rupture—4 to 12 days—correlates with the histologic finding of maximal cardiac muscle degeneration.

55. Which of the following clinical characteristics is/are associated with a higher mortality after emergency CABG for failed PTCA?
A. Multivessel disease.
B. Rescue atherectomy.
C. Cardiogenic shock prior to CABG.
D. Previous bypass surgery.
E. All of the above.
Answer: ACD

56. Which statement(s) about operative mortality and perioperative incidence of myocardial infarction for elective CABG (X) versus emergency CABG following failed PTCA (Y) is/are accurate?
A. The operative mortality is higher for Y but the incidence of perioperative myocardial infarction is unchanged between X and Y.
B. The operative mortality is unchanged between X and Y but the perioperative incidence of myocardial infarction is higher in Y.
C. The operative mortality and perioperative incidence is higher in X than in Y.
D. The operative mortality and perioperative incidence of myocardial infarction are no different for X and for Y.
Answer: C

57. Which of the following statements about patients treated by placement of an internal mammary artery (IMA) bypass graft at primary CABG is/are correct?
A. The risk for morbidity and mortality from reoperative coronary bypass grafting is increased.
B. Left ventricular function is better preserved at the time of reoperation.
C. The risk of sternal wound complications is greatly increased if the contralateral IMA is harvested at the time of reoperation.
D. A light clamp should be applied to the IMA pedicle to limit cardiac warming during cardioplegic arrest at the time of reoperation.
E. A functional study demonstrating a large portion of myocardium at risk should be obtained before reoperation.
Answer: BDE

DISCUSSION: Patients who have an intact IMA graft should have severe anginal symptoms and a significant portion of myocardium at risk before reoperative coronary bypass grafting is considered. A functional study may better define the proportion of myocardium at risk for ischemia and infarction. Patients with an intact IMA graft are less likely to require reoperation, but if stenosis distal to the IMA and disease in other vein grafts have progressed or if a large portion of myocardium is at risk, reoperation is recommended. The presence of an intact IMA is not a contraindication to reoperation; in fact, this population of patients have better-preserved ventricular function and are, perhaps, better candidates for reoperation. Placement of an IMA graft at the time of the first operation was critically important, neutralizing the adverse effects of elevated serum cholesterol, hypertension, and smoking on reoperation-free survival. The risk of damaging an intact IMA graft is 3% to 5%. A lateral projection of the IMA at cardiac catheterization will define its course, particularly in relation to the sternum, to allow more careful sternal re-entry. The IMA should be minimally dissected and a light clamp applied during cardioplegic arrest to limit cardiac warming and improve myocardial protection. The IMA may be detached and recycled if needed. The use during reoperation of the contralateral IMA does not increase the risk of sternal wound complications.

58. Considering the results of coronary reoperation in comparison to primary CABG, choose the incorrect statement:
A. Operative morbidity and mortality are increased over those for primary CABG.
B. Mortality most often stems from cardiac causes after reoperation.
C. Survival of patients after hospital discharge following coronary reoperation is nearly equivalent to survival after primary CABG.
D. Compared to primary CABG, return of anginal symptoms is delayed after reoperative CABG.
E. Myocardial protection and the risk of myocardial infarction in reoperation are complicated by increased noncoronary collaterals, patent atherosclerotic saphenous vein grafts, and more diffuse coronary atherosclerosis.
Answer: D

DISCUSSION: The mortality and morbidity after reoperative CABG are approximately two to three times that of primary CABG. In contrast to primary CABG, where the majority of deaths are a result of failure of other organ systems, 75% to 85% of deaths after reoperative CABG are due to cardiac causes. The increased risk of reoperation results from more advanced native vessel disease, a longer cross-clamp time, a longer cross-clamp time per graft, a longer time to initiate cardiopulmonary bypass, and increased blood loss. The increased frequency of pulmonary complications, myocardial infarction, neurologic injury, and death, stems from the technical factors of reoperation and the characteristics of the patient population. Technical factors include difficulty in finding targets secondary to pericardial reaction and more diffusely diseased vessels, the risks of injuring the heart or great vessels on sternal re-entry, increased blood loss and risk of requiring transfusion, less available conduit for bypass, and greater difficulty in providing optimal myocardial protection. Characteristics of this patient population that increase risks include advanced age and diminished ventricular function. While survival after reoperation is nearly equivalent to that after primary CABG, angina symptoms return at twice the frequency in the first year after operation (47% versus 20%) then return at a similar annual rate (2% to 3%).

59. Which statements are correct comparisons of gated equilibrium and initial-transit radionuclide measurements of left ventricular function?
A. Gated equilibrium techniques provide more accurate measurements of ejection fraction than initial-transit methods.
B. Left ventricular imaging time for a gated equilibrium study is at least 10 times that of an initial-transit study.
C. Both techniques require the same radiopharmaceuticals.
D. Both techniques require a bolus injection.
Answer: B

DISCUSSION: Both techniques are equally accurate for measuring left ventricular ejection fraction. The left ventricular imaging time for gated equilibrium studies is at least 10 times that of initial-transit radionuclide angiocardiography. Initial-transit techniques use data from fewer than 10 heartbeats, whereas equilibrium studies require more than 100 heartbeats to acquire data with similar information density. The initial-transit study can be performed with any radioactive substance, but the gated equilibrium technique requires a radiopharmaceutical that remains within the blood pool for imaging. The initial-transit radionuclide study requires a bolus injection, but an equilibrium study can be acquired up to several hours after injection and must be acquired while the tracer is at equilibrium.

60. The radionuclide variable that contains the greatest amount of prognostic information in patients with coronary artery disease is:
A. Exercise ejection fraction.
B. Change in regional wall motion from rest to exercise.
C. Maximal cardiac output during exercise.
D. Change in heart rate during exercise.
Answer: A

DISCUSSION: The exercise ejection fraction is the single most important radionuclide variable relating to subsequent cardiac death or myocardial infarction, and this single variable contains 80% of the prognostic information in the test.

61. Which of the following statements about left ventricular aneurysm is/are correct?
A. Ventricular aneurysms are commonly associated with systemic arterial embolization.
B. Absent collateral circulation in an area of myocardium supplied by an acutely occluded artery favors aneurysm formation.
C. Posterobasal aneurysms are more common than those located in the anteroapical region.
D. Aneurysm repair can improve associated cardiac valve dysfunction.
E. Persistent ST segment elevation after acute myocardial infarction suggests aneurysm formation.
Answer: BDE

DISCUSSION: The mural thrombus frequently present on the endocardial surface of an aneurysm is usually adherent and rarely embolizes. Collateral circulation, when present, often prevents transmural necrosis following arterial occlusion. Since the left anterior descending coronary artery is the vessel most commonly occluded in patients with ventricular aneurysms, most of the aneurysms are anteroapical. Improvements in ventricular contour and reduction in ventricular volume accompany aneurysm repair. Although persistent elevation of ST segments following myocardial infarction is very suggestive of aneurysm formation, the diagnosis should be confirmed by more definitive tests.

62. Which of the following factors does/do not increase early mortality associated with repair of left ventricular aneurysm?
A. Class IV cardiac status.
B. Size of aneurysm.
C. Presence of left main coronary disease.
D. Emergent operation.
E. Location of aneurysm.
Answer: BE

DISCUSSION: Class IV cardiac status and emergent operation both imply extensive myocardial damage and in most reported series are associated with increased operative mortality. Similarly, the presence of significant stenosis of the left main coronary artery increases the operative mortality of virtually all cardiac procedures. On the other hand, neither the size of the aneurysm nor its location affect early operative mortality, despite the fact that posterior aneurysms are technically more difficult to repair and are much less common.

63. The most effective medical therapy in ameliorating the symptoms of Kawasaki's disease and preventing the development of giant coronary artery aneurysms is administration of:
A. Antibiotics.
B. Antiviral agents.
C. Aspirin.
D. Gamma globulin.
E. Glucocorticoids.
Answer: D

DISCUSSION: Kawasaki's disease is a multisystemic disorder of unknown cause and is the leading cause of acquired heart disease in children in both Japan and the United States. Although many clinical aspects of Kawasaki's disease suggest an infectious agent, the search for a single agent has been unsuccessful; neither antibacterials nor antivirals have a role in the therapy of Kawasaki's disease. The goal of initial therapy of Kawasaki's disease is the reduction of inflammation, including coronary and myocardial inflammation. After the diagnosis of Kawasaki's disease is secured, patients are treated with intravenous gamma globulin and large doses of aspirin. Gamma globulin, 2 gm. per kg., is administered as a single infusion over 12 hours. Treatment with intravenous immune globulin has been shown to decrease the duration of fever, to decrease the prevalence of cardiovascular complications, and to prevent the progression to giant coronary aneurysms. High-dose aspirin therapy contributes to the resolution of the acute manifestations of Kawasaki's disease. When Kawasaki's disease is diagnosed, children are given a regimen of aspirin, 100 mg. per kg. per day, which is continued until defervescence. Thereafter, they are maintained on small doses of aspirin, 3 to 5 mg. per kg. per day, for 8 weeks. The goal of aspirin therapy is amelioration of symptoms and prevention of the thrombotic and embolic complications of Kawasaki's disease. Aspirin does not decrease the risk of the development of coronary aneurysms. There is no role for glucocorticoids in the treatment of Kawasaki's disease.

64. Indications for surgical intervention in Kawasaki's disease include which of the following?
A. The presence of multiple coronary artery aneurysms.
B. Myocardial infarction and severe left ventricular dysfunction.
C. The presence of a 5 mm. aneurysm in the right coronary artery.
D. Progressive stenosis in the left anterior descending coronary artery.
E. None of the above.
Answer: D

DISCUSSION: The indications for surgical treatment of Kawasaki's disease include: (1) progressively stenotic coronary lesions demonstrated on coronary arteriography, with no distal coronary aneurysms with stenosis; (2) localized aneurysm with significant stenosis in the left main coronary artery; (3) significant stenosis in two coronary arteries; (4) presence of collateral vessels arising from a coronary artery with a proximal aneurysm; (5) progressive stenosis in the left anterior descending coronary artery; and (6) presence of a left ventricular aneurysm. Advanced thrombosis of coronary aneurysms causing critical stenoses in multiple coronary arteries is the most common indication for surgical intervention.

65. Which of the following statements about the pathophysiology of Ebstein's anomaly is/are true?
A. The tricuspid valve is usually insufficient.
B. Typically there is a left-to-right shunt across the ASD.
C. The redundant anterior leaflet of the tricuspid valve may cause obstruction of the right ventricular outflow tract.
D. Pulmonary hypertension is a common late complication.
E. High pulmonary vascular resistance in neonates exacerbates tricuspid regurgitation and cyanosis.
Answer: ACE

DISCUSSION: Ebstein's anomaly is characterized by downward displacement of the tricuspid valve into the right ventricular cavity. The anterior leaflet is large and “sail-like,” while the other two leaflets are rudimentary. Although the tricuspid valve occasionally may be stenotic, it is usually regurgitant. The tricuspid regurgitation and functional right ventricular outflow tract obstruction caused by the large anterior leaflet lead to right-to-left shunting across the ASD. Systemic venous hypertension is often present, but pulmonary hypertension almost never occurs with this malformation. Finally, neonates that present with Ebstein's anomaly are markedly cyanotic, owing to their high pulmonary vascular resistance. This causes a functional pulmonary atresia, which increases right-to-left shunting across the ASD.

66. In the surgical treatment of Ebstein's anomaly, which of the following is/are true?
A. In neonates, the tricuspid valve orifice may be oversewn and a systemic-pulmonary shunt created to provide pulmonary blood flow.
B. Techniques in repair of the tricuspid valve do not utilize plication of the atrialized right ventricle.
C. Closure of the ASD alone is adequate repair of the malformation.
D. If tricuspid valve replacement is performed, the valve should be sutured above the coronary sinus to avoid injury to the conduction system.
E. Currently, mechanical prostheses are recommended for tricuspid valve replacement because the durability of bioprosthetic valves in the tricuspid position is so poor.
Answer: AD

DISCUSSION: In a recent report on the surgical treatment of Ebstein's anomaly in neonates, Starnes described a technique consisting of oversewing the tricuspid valve, atrial septectomy, and placement of a systemic-pulmonary shunt. These patients are then later staged to a modified Fontan procedure when they outgrow their shunts. Repair of the ASD alone was performed early in the treatment of Ebstein's anomaly and was associated with high mortality rates. It is not considered an adequate repair. Most techniques in tricuspid valve repair for Ebstein's malformation utilize plication of the atrialized right ventricle in addition to excision of redundant atrial tissue. If tricuspid valve replacement is necessary, current approaches utilize bioprosthetic valves because of their excellent durability in the tricuspid position. Placement of the valve ring above the coronary sinus has been associated with a lower rate of postoperative heart block.

67. Which of the following congenital lesions of the coronary circulation causes a cardiac murmur that is similar to the murmur produced by a PDA?
A. Origin of the left coronary artery from the pulmonary artery.
B. Origin of the right coronary artery from the pulmonary artery.
C. Coronary artery fistula.
D. Membranous obstruction of the ostium of the left main coronary artery.
Answer: C

DISCUSSION: The major clinical finding with a coronary artery fistula is a continuous murmur over the site of the abnormal communication. This murmur may closely resemble that of PDA.

68. The congenital coronary lesion most likely to cause death in infancy is:
A. Coronary artery fistula.
B. Origin of the left coronary artery from the pulmonary artery.
C. Origin of the right coronary artery from the pulmonary artery.
D. Congenital coronary aneurysm.
Answer: B

DISCUSSION: The prognosis for most patients with origin of the left coronary artery from the pulmonary artery is poor. It has been estimated that 95% of patients with this anomaly die within the first year of life unless surgical therapy is undertaken. Patients whose right coronary artery originates from the pulmonary artery are usually asymptomatic. Patients with coronary fistulas occasionally suffer congestive heart failure early. Congenital aneurysms of the coronary arteries are most often asymptomatic until complications occur, usually later in life.

69. The congenital coronary lesion associated with minimal or absent clinical manifestations and nearly normal life expectancy is:
A. Congenital origin of both coronary arteries from the pulmonary artery.
B. Congenital coronary artery fistula.
C. Membranous obstruction of the ostium of the left main coronary artery.
D. Congenital origin of the right coronary artery from the pulmonary artery.
Answer: D

DISCUSSION: Clinical manifestations of congenital origin of the right coronary artery from the pulmonary artery are usually minimal or absent. This malformation is thought to have been associated with death. The oldest reported patient with this malformation died at age 90 years from unrelated problems.

70. Which of the following is/are indications for aortic valve replacement for aortic stenosis?
A. Syncope.
B. Congestive heart failure.
C. Angina.
D. Transvalvar gradient of 35 mm. Hg without symptoms.
Answer: ABC

DISCUSSION: With progressive narrowing of the aortic valve area from the normal 3 to 4 sq. cm. to 1 sq. cm., patients become symptomatic. The classic symptoms produced by aortic stenosis are syncope, congestive heart failure, and angina. Once symptoms occur, life expectancy is limited to 2 to 5 years. Therefore, symptomatic aortic stenosis is an indication for aortic valve replacement. The risk of death with asymptomatic aortic stenosis is quite low, and aortic valve replacement is not indicated for asymptomatic patients with a transvalvar gradient less than 50 mm. Hg.

71. Under which of the following circumstances is medical management logical?
A. Moderate aortic insufficiency seen on echocardiography with normal left ventricular end-systolic dimensions.
B. Moderate to severe aortic insufficiency seen on echocardiography with cardiomegaly on chest roentgenography.
C. Moderate aortic insufficiency seen on echocardiography with symptoms of congestive heart failure.
D. Moderate aortic insufficiency with an end-systolic left ventricular dimension of 70 mm. as seen on echocardiography.
Answer: A

DISCUSSION: The left ventricle is usually able to compensate for a long time for the increased volume load imposed by aortic insufficiency. The natural history of asymptomatic aortic stenosis is excellent; 10-year survival for moderate aortic insufficiency managed medically is as high as 85% to 95%. Medical management typically consists of diuretics and afterload reduction; however, once the compensatory mechanisms begin to fail, survival is limited. Half of patients with signs or symptoms of congestive heart failure die within 2 years. Therefore, evidence of left ventricular dilation by echocardiography (left ventricular end-systolic dimension greater than 55 mm., cardiomegaly on chest roentgenography) or symptoms of congestive heart failure are indications for aortic valve replacement.

72. Which of the following may be indications for operation for mitral stenosis?
A. Systemic embolization.
B. Infective endocarditis.
C. Onset of atrial fibrillation.
D. Worsening pulmonary hypertension.
Answer: ABCD

DISCUSSION: Although each is only a relative indication for operation for mitral stenosis, systemic embolization, infective endocarditis, onset of atrial fibrillation, and worsening pulmonary hypertension may each be an indication for operation for mitral stenosis. Systemic embolization, infective endocarditis, and onset of atrial fibrillation are each complications of mitral stenosis that portend a risk of further complication with continued medical therapy. Patients older than 40 years with mild class II congestive heart failure stand to gain symptomatically from operation for significant mitral stenosis and do not run excessive risk of multiple reoperative procedures.

73. Which of the following is/are not true?
A. Operation improves survival in patients with severe, symptomatic mitral valve disease.
B. Left ventricular dilatation with class I or class II heart failure is an indication for operation with mitral regurgitation.
C. Tricuspid regurgitation is most commonly caused by abnormalities of the leaflets themselves.
D. Mitral valve replacement requires resection of the mitral valve leaflets and chordae.
Answer: CD

DISCUSSION: Relative to medical therapy alone, surgical therapy has been shown to improve survival in patients with severe, symptomatic mitral valve disease. In mitral regurgitation, left ventricular dilatation is an indication for surgical intervention regardless of failure symptoms. The most common cause of tricuspid regurgitation is tricuspid annular dilatation without abnormalities of the leaflets themselves. Mitral valve replacement with preservation of both leaflets or at least the posterior leaflet is well described and is probably advisable for most patients to preserve left ventricular function and reduce the probability of ventricular-annular separation.

74. Which of the following generally are not symptoms of tricuspid valve disease?
A. Pulmonary edema.
B. Hepatic failure.
C. Anasarca.
D. Hoarseness.
Answer: AD

DISCUSSION: Hepatic failure and anasarca are indeed common symptoms of severe, long-standing tricuspid valve disease with increased venous pressure. Pulmonary edema is a consequence of left-sided heart disease and does not result from a tricuspid lesion. Similarly, hoarseness is most common after mitral valve disease with left atrial enlargement and is rarely due to tricuspid valve disease alone.

75. Which of the following are relative indications for mitral valve replacement, as opposed to mitral valve repair?
A. Extensive leaflet calcification.
B. Mitral regurgitation.
C. Chordal rupture of the anterior mitral leaflet.
D. Significant annular dilatation.
Answer: A

DISCUSSION: Extensive mitral valve calcification is a relative indication for mitral valve replacement. Mitral regurgitation or significant annular dilatation may, however, be amenable to mitral valve repair. Chordal rupture of the anterior leaflet is generally reparable using chordal transposition or polytetrafluoroethylene (PTFE) chordae.

76. Which of the following are not true?
A. Tricuspid regurgitation due to annular dilatation alone generally does not require valve replacement.
B. Mitral valve replacement with either a bioprosthesis or a mechanical valve requires warfarin anticoagulation.
C. Tricuspid valve replacement is generally an indication for using a tissue valve.
D. Chronic renal failure is a relative indication for tissue valves.
Answer: B

DISCUSSION: Tricuspid regurgitation due to annular dilatation alone generally can be treated with tricuspid annuloplasty or with correction of associated mitral valve disease. Mitral valve replacement with a mechanical valve does require warfarin anticoagulation; however, mitral valve replacement with a bioprosthesis may be managed with aspirin alone. Tricuspid valve replacement is an indication for using a tissue valve because of the significant incidence of valve thrombosis when a mechanical valve is in the tricuspid position. Chronic renal failure is a relative indication for tissue valves because valve calcification is rare and because anticoagulation of patients on dialysis carries high risks of morbidity and mortality.

77. Which of the following are relative indications for mechanical, as opposed to tissue, valve replacement?
A. Patient younger than 30 years.
B. Young female patient who desires children.
C. An elderly patient.
D. Tricuspid valve replacement.
Answer: A

DISCUSSION: Age younger than 30 years is a relative indication for mechanical valves because of an increased incidence of calcification of tissue valves in younger persons. A young female who desires children would be a relative contraindication to mechanical replacement because of the risk of teratogenesis and hemorrhage during pregnancy secondary to warfarin therapy. Advanced age is a relative indication for biologic valves to avoid complications of anticoagulation and because the probability of reoperation is low. Tricuspid valve replacement is a relative contraindication to mechanical valve replacement, owing to the increased incidence of tricuspid valve thrombosis with a mechanical prosthesis.

78. Which of the following statements are not true?
A. Bioprosthetic valves have a relatively high incidence of hemolysis.
B. Bioprosthetic valves have a lower incidence of postoperative prosthetic valve endocarditis.
C. Mechanical valves develop structural failure after an average of 7 to 10 years.
D. Mortality attributable to warfarin therapy approaches 5% per patient-year.
Answer: ABCD

DISCUSSION: Bioprosthetic valves have a relatively low incidence of hemolysis. Bioprosthetic and mechanical valves do not differ significantly in the associated incidences of postoperative prosthetic valve endocarditis. Bioprosthetic valves develop structural failure after an average of 7 to 10 years, whereas mechanical valves have a life span of well beyond 10 years. The mortality attributable to warfarin therapy approaches 1% per patient-year.

79. Which of the following are not generally associated with mitral stenosis without regurgitation?
A. Pulmonary hypertension.
B. Pulmonary edema.
C. Left ventricular dilatation.
D. An opening snap after the second heart sound.
Answer: ABD

DISCUSSION: Pure mitral stenosis without regurgitation may be associated with pulmonary hypertension, pulmonary edema, and an opening snap after the second heart sound. Left ventricular dilatation would be rare in pure mitral stenosis and generally occurs with volume or pressure overload of the left ventricle, as with mitral regurgitation.

80. The most common location of accessory pathways in patients with the Wolff-Parkinson-White syndrome is the:
A. Left free wall.
B. Right free wall.
C. Posterior septum.
D. Anterior septum.
Answer: A

DISCUSSION: All major published series of the Wolff-Parkinson-White syndrome indicate that the majority of all accessory pathways appear in the left free wall space. In one series, approximately 60% of all accessory pathways occur in the left free wall space. In Ebstein's anomaly, pathways are usually located in the posterior septum and/or right free wall spaces. If these patients are excluded, approximately 70% of pathways occur in the left free wall space.

81. The anatomic electrophysiologic basis of AV node re-entry tachycardia is dual AV node conduction pathways. AV node re-entry tachycardia is most likely to occur with which of the following electrophysiologic aberrations?
A. Proximal antegrade block in the slow conduction pathway.
B. Proximal retrograde block in the slow conduction pathway.
C. Proximal antegrade block in the fast conduction pathway.
D. Proximal retrograde block in the fast conduction pathway.
Answer: C

DISCUSSION: A retrograde conduction block in either the slow or fast pathway would be likely to prevent a re-entrant circuit from developing. A proximal antegrade block in the slow conduction pathway is extremely unusual because of the short refractory period of the slow conduction pathway. The most common conduction block that occurs in patients with dual AV node physiology is a proximal antegrade conduction block in the fast pathway because of its longer refractory period. This antegrade block in the fast conduction pathway allows AV conduction to occur via the slow pathway and to return in retrograde fashion up the fast pathway to establish the re-entrant circuit responsible for AV node re-entry tachycardia.

82. Match the four surgical procedures that have been developed for the treatment of atrial fibrillation with the major detrimental sequela(e) of atrial fibrillation that each corrects.
A. His bundle ablation.
B. Left atrial isolation procedure.
C. Corridor procedure.
D. Maze procedure.
1. Patient's sensation of irregular heart rhythm.
2. Hemodynamic compromise because of loss of AV synchrony.
3. Increased vulnerability to thromboembolism.
Answer: A-1. B-1,2. C-1. D1,2,3

DISCUSSION: The surgical procedure most commonly employed for the treatment of atrial fibrillation is catheter ablation of the His bundle. The International Catheter Ablation Registry reveals that more than 60% of patients who undergo elective catheter ablation of the bundle of His do so for the treatment of atrial fibrillation. His bundle ablation is an isolation procedure, in that it confines the atrial fibrillation to the atria and protects the ventricles from the unpleasant sensation of an irregular heartbeat. Because the atria continue to fibrillate there is no restoration of AV synchrony, and therefore there is no improvement in cardiac hemodynamics. Moreover, the continuing fibrillation of the left atrium means that postoperatively the patient is still at the same risk for thromboembolism. Thus, His bundle ablation corrects only one of the three detrimental sequelae of atrial fibrillation, namely the arrhythmia problem.
The left atrial isolation procedure confines atrial fibrillation to the left atrium, allowing the sinus node to drive the remainder of the heart in a normal sinus rhythm. Thus, it alleviates the unpleasant sensation of an irregular heartbeat. In addition, because AV synchrony is re-established between the right atrium and right ventricle, right-sided cardiac output is restored to normal. This means that normal cardiac output is delivered through the lungs to the left side of the heart. In the presence of a normal left ventricle the left-sided cardiac output is also normal, despite the fact that left-sided AV synchrony is not present; however, because the left atrium is allowed to fibrillate, the vulnerability to thromboembolism remains unchanged postoperatively.
The corridor procedure allows the sinus node to drive the heart in normal sinus rhythm, but because of the total isolation of the sinoatrial and AV nodes from the remainder of the atria, the atria may continue to fibrillate. Even if they do not, in effect they are isolated from their respective ventricles so that AV synchrony is lost on both sides of the heart. As a result, the corridor procedure alleviates the sensation of arrhythmia but does not restore normal hemodynamics, nor does it decrease vulnerability to thromboembolism. The maze procedure ablates the re-entrant circuits responsible for atrial fibrillation and restores the normal sinus rhythm. Thus, it alleviates the sensation of arrhythmia, restores normal hemodynamics, and alleviates the vulnerability to thromboembolism.

83. All of the following statements about nonischemic ventricular tachyarrhythmias are true except:
A. They usually occur in the right ventricle.
B. They are usually associated with a left bundle branch block pattern during the tachycardia.
C. They are usually more refractory to medical therapy than ischemic ventricular tachyarrhythmias.
D. They usually occur as a result of automaticity rather than re-entry.
Answer: D

DISCUSSION: Nonischemic ventricular tachyarrhythmias usually occur in the right ventricle, and as a result the ECG shows a left bundle branch block–type pattern during ventricular tachycardia. These arrhythmias are notoriously refractory to medical therapy and they occur almost exclusively on a re-entrant basis.

84. Which of the following statements about left atrial myxoma are true?
A. This lesion, by site and histology, is the most common primary cardiac tumor.
B. It is best diagnosed by cardiac catheterization and angiography.
C. The symptom complex can mimic collagen vascular disease.
D. It has an intracavitary growth pattern.
E. It has a multicentric origin in the chamber wall.
Answer: ACD

DISCUSSION: Eighty per cent of primary cardiac tumors are benign, and half of these benign tumors are myxomas. Seventy-five per cent of myxomas arise in the left atrium in the region of the fossa ovalis. Echocardiography is the technique of choice in the evaluation of intracardiac tumors, and findings suggestive of myxoma occur in 95% of patients examined. Invasive procedures, with the attendant risk of tumor embolization, are not warranted. Owing to an autoimmune phenomenon, left atrial myxomas can present with systemic constitutional symptoms of fever, malaise, weight loss, polymyositis, and blood dyscrasias that mimic collagen vascular disease. Of surgical significance is the fact that most myxomas rarely extend deeper than the endocardium but grow as polypoid, intracavitary masses. Attachment by a vascular stalk thus allows tumor mobility, predisposing to embolization and interference with mitral valve competence and causing characteristic echocardiographic findings.

85. Which of the following statements about malignant cardiac tumors are true?
A. Sarcomas are the most frequent primary malignancy.
B. Metastatic tumors are usually asymptomatic.
C. Adjuvant chemotherapy and irradiation are efficacious in prolonging survival.
D. Intra-atrial extension of renal neoplasms is a contraindication for surgical resection.
E. Constrictive physiology is an indication for operation.
Answer: AB

DISCUSSION: Twenty per cent of primary cardiac tumors are some variant of sarcoma. Precise histologic classification is not imperative, as all have a similar clinical picture with rapid systemic dissemination and aggressive local invasion. In contrast, metastatic tumors cause symptoms in only 10% of patients. Unfortunately, most primary and secondary cardiac malignancies infrequently respond to systemic chemotherapy or mediastinal irradiation. Surgical treatment is most successful with renal tumors extending into the right atrium. Significant 5-year survival can be achieved with concomitant nephrectomy and intra-atrial resection of the tumor thrombus. Relief of tamponade is worthwhile; however, extensive decortication provides little help.

86. Disadvantages of temporary pacing through skin electrodes applied to the anterior chest wall include all of the following except:
A. Skin burns.
B. Painful chest wall muscle contractions.
C. Ventricular fibrillation.
D. Inability to pace.
Answer: C

DISCUSSION: In 1952 Zoll first described successful pacing through external metal electrodes applied to the anterior chest wall. Clinical experience with this technique has shown that it is both feasible and lifesaving for temporary pacing; however, disadvantages of the external pacing technique include skin burns when too little electrode jelly is applied, painful chest wall muscle contractions, and inability to pace in thick-chested or emphysematous patients. Ventricular fibrillation induced by external temporary cardiac pacing is exceedingly rare.

87. In adults the most common cause of acquired complete heart block is:
A. Ischemic heart disease.
B. Sclerodegenerative disease.
C. Traumatic injury.
D. Cardiomegaly.
Answer: B

DISCUSSION: Before permanent pacemakers were available, 50% of patients with complete heart block died within 1 year. The most common cause of acquired complete heart block in adults is sclerodegenerative disease of the cardiac skeleton and AV conduction system. Other less common causes of complete heart block include ischemic heart disease, cardiomyopathic processes, Chagas' disease, and traumatic injury.

88. The most common indication for permanent pacing is:
A. Complete heart block.
B. Second-degree AV block.
C. Chronic bifascicular block.
D. Sick sinus syndrome.
Answer: D

DISCUSSION: Patients with sinus node dysfunction may develop a number of arrhythmias, such as inappropriate sinus bradycardia, chronotropic incompetence, sinoatrial exit block, and sinus arrest. This group of rhythm disorders typically occurs in older patients with or without underlying heart disease and is collectively known as the “sick sinus syndrome.” In addition, many patients with sick sinus syndrome have associated atrial tachyarrhythmias, particularly atrial fibrillation. This association of atrial tachyarrhythmias in patients with the sick sinus syndrome is called the tachycardia-bradycardia (or tachy-brady) syndrome. The most common indication for permanent pacing occurs in patients with the sick sinus syndrome.

89. Decreasing pacemaker electrode tip size results in:
A. Lower pacing thresholds.
B. Improved electrogram sensing.
C. Decreased battery life.
D. Less patient discomfort.
Answer: A

DISCUSSION: Decreasing pacemaker electrode tip size results in lower pacing thresholds, both at the time of implant and subsequently, because of higher current density. However, better sensing function is directly related to electrode area and is adversely affected by small electrode size. Therefore, a compromise between pacing and sensing efficiency is required. Typical electrode surface areas for pacing are between 8 and 10 sq. mm.

90. At the time of ventricular pacemaker implantation, lead resistance is determined at a voltage near that of the pacemaker's output. The calculated resistance at 5 volts should range from:
A. 10 to 100 ohms.
B. 125 to 250 ohms.
C. 300 to 800 ohms.
D. 1000 to 1500 ohms.
Answer: C

DISCUSSION: At the time of pacemaker implantation, in addition to measuring pulse amplitude (voltage and current) and pulse width, resistance is also determined. As described by Ohm's law, resistance is calculated by dividing voltage by current. Resistance calculations are made at a voltage near that of the pacemaker's output. The calculated resistance at 5 volts should range from 300 to 800 ohms. An unsatisfactorily low resistance is unsatisfactory because current is wasted and battery life is shortened. Conversely, excessively high resistance (more than 800 ohms) increases battery life but decreases the current delivered to the heart for pacing.

91. A ventricular inhibited-demand pacemaker using the Intersociety Commission for Heart Disease Resources (ICHD) code is designated as:
A. DVI.
B. VVI.
C. VOO.
D. VDD.
Answer: B

DISCUSSION: A ventricular inhibited-demand pacemaker using the ICHD code is designated as VVI. As the ICHD code states, the pacemaker senses intrinsic ventricular activity and is inhibited when this activity exceeds the standby or escape rate of the pacemaker. When the intrinsic ventricular rate falls below the escape rate of the pulse generator, the pacemaker begins to function at its programmed rate.

92. In rate-modulated pacing, the pacing rate is determined by a physiologic parameter other than atrial rate and is measured by a special sensor in the pacemaker or pacing lead. The most commonly used physiologic parameter in rate-modulated pacemakers is:
A. QT interval.
B. Venous blood temperature.
C. Mixed venous oxygen saturation.
D. Body motion.
Answer: D

DISCUSSION: During exertion, the required increase in cardiac output is obtained mostly by the increase in paced heart rate, although increased venous filling and maintenance of AV synchrony are also important contributors. The most commonly used physiologic parameters in rate-modulated pacemakers at the present time are body motion and minute ventilation. Other parameters that are less commonly used or under evaluation include QT interval, venous blood temperature, mixed venous oxygen saturation, contractility, stroke volume, venous pH, and the paced depolarization gradient.

93. The most common pacing mode used in patients with symptomatic bradycardia and an underlying sinus rhythm is:
A. AAI.
B. DVI.
C. DDD.
D. VVI.
Answer: C

DISCUSSION: “Universal,” or DDD, pacing has been shown to have many benefits over other pacing modalities, including the ability to track the intrinsic sinus rate, pace the atrium and ventricle, maintain atrioventricular synchrony, and avoid the pacemaker syndrome. Recognition of these benefits has steadily increased the use of DDD pacemakers in the last decade, and at the present time DDD is the most common pacing mode.

94. A transvenous pacemaker generator pocket should be placed on the patient's nondominant side over the:
A. Anteromedial chest wall.
B. Anterolateral chest wall.
C. Inferomedial chest wall.
D. Inferolateral chest wall.
Answer: A

DISCUSSION: Bipolar impulse generators can be placed either in the subcutaneous tissue or beneath the muscle. Migration of the impulse generator most commonly occurs in infraclavicular pacemakers pockets. Migration tends to follow the curvature of the chest wall, and the impulse generator tends to migrate laterally. This can be prevented by creating an anteromedial pocket large enough to contain the impulse generator and lead. In susceptible persons the impulse generator can be further secured to the chest wall to prevent migration.

95. Pacemaker-mediated tachycardia is caused by:
A. Pacemaker induction of atrial fibrillation.
B. Sensing of retrograde atrial activation.
C. Inappropriate ventricular sensing.
D. Lead fracture.
Answer: B

DISCUSSION: Pacemaker-mediated tachycardia occurs in the setting of intact ventriculoatrial conduction. Typically, premature ventricular contractions may be conducted retrogradely through the AV conduction system and cause retrograde activation of the atrium. If this retrograde atrial activation occurs after completion of the programmed pacemaker ventriculoatrial refractory period, the atrial event is sensed by the DDD pacemaker and evokes a paced ventricular event that may cause further VA conduction. If each ventricularly paced event results in atrial activation sensed by the pacemaker, pacemaker-mediated tachycardia will be generated.

96. Which cardiovascular pharmacologic agents are safe to use during routine abdominal surgery in a 75-year-old woman with documented hypertension and mild coronary artery disease?
A. Nifedipine.
B. Atenolol.
C. Hydralazine.
D. Captopril.
E. Reserpine.
Answer: ABD

DISCUSSION: Nifedipine is tolerated fairly well by elderly patients and is safe to use in the perioperative period with close hemodynamic monitoring. Atenolol is a safe beta-blocker to use during the perioperative period and provides protection from cardiac rhythm disturbances and rebound hypertension. Hydralazine, if given without a beta-blocker, often elicits reflex tachycardia, which limits its usefulness. Captopril is a safe agent that does not appear to interfere with the normal cardiovascular response to anesthesia, and abrupt withdrawal of this agent may result in severe hypertension and should be avoided. Reserpine is an adrenergic inhibitor that may depress cardiac output and result in hypotension, so its use in the perioperative setting is limited.

97. Which inotropic drugs are safe for use in elderly patients with mild congestive heart failure in the postoperative period?
A. Digitalis compounds.
B. Dopamine.
C. Amrinone.
D. Melrinone.
E. Dobutamine.
Answer: BCDE

DISCUSSION: Dopamine and dobutamine stimulate cardiac beta-receptors and are very useful in providing inotropic support for patients in the postoperative period. Melrinone and amrinone are phosphodiesterase inhibitors that have strong inotropic effects while causing arterial and venous dilation. Melrinone and amrinone are useful in patients with low cardiac output, especially in the setting of congestive heart failure. Digitalis compounds can be troublesome in the postoperative period owing to the toxic effects of these agents. Furthermore, perioperative hypoxia and hypokalemia increase myocardial susceptibility to digitalis-induced ventricular arrhythmias.

98. Which anticoagulation treatment plan(s) is/are appropriate for a 72-year-old man with a mechanical heart valve in place who takes Coumadin (warfarin) and now requires elective left colon resection?
A. Discontinuation of Coumadin therapy on the day of the operation.
B. Discontinuation of Coumadin therapy on the day of the operation with replacement of clotting factors with fresh frozen plasma (FFP) before the start of the surgical procedure.
C. Discontinuation of Coumadin therapy 5 days before operation with no further anticoagulation therapy before surgery.
D. Discontinuation of Coumadin therapy 5 days before operation with the institution of intravenous heparin as the prothrombin time normalizes.
E. Discontinuation of Coumadin therapy 2 days before operation followed by large doses of aspirin.
Answer: D

DISCUSSION: Many patients who require anticoagulation with Coumadin for underlying cardiac disease need to undergo routine general surgical procedures. The current recommendations for patients who have been on long-term Coumadin therapy is to discontinue Coumadin 5 days before an operative procedure. As the patient's prothrombin time normalizes intravenous heparin should be started. The patient should be maintained on a therapeutic dose of heparin with an activated partial thromboplastin time (aPTT) of at least 60 seconds. Heparin should then be withheld approximately 4 to 6 hours before the surgical procedure. The operation is then performed in a “heparin window,” where the level of anticoagulation can easily be titrated or totally reversed with protamine if necessary.

99. Which of the following treatment plans is appropriate for a 68-year-old patient with moderate to severe congestive heart failure following a major abdominal surgical procedure?
A. Aggressive use of inotropic support with epinephrine.
B. Aggressive diuresis with furosemide and inotropic support with dopamine.
C. Afterload reduction with nitroprusside and inotropic support with dopamine.
D. Close perioperative monitoring and inotropic support with melrinone.
E. Intravenous digitalis with diuresis using furosemide as needed.
Answer: CD

DISCUSSION: Treatment of congestive heart failure using epinephrine alone is contraindicated owing to the profound vasoconstrictive properties of epinephrine, which only exacerbate the heart failure. Diuresis with furosemide and inotropic support with dopamine is acceptable for patients with mild congestive heart failure; however, in the postoperative period pharmacologic diuresis can lead to profound hypovolemia requiring continuous invasive hemodynamic monitoring. The ideal choice for the postoperative management of patients with severe congestive heart failure is afterload reduction using nitroprusside and inotropic support with dopamine. This helps to stimulate the failing heart while decreasing the afterload pressure against which the heart must pump. Melrinone is a useful phosphodiesterase inhibitor, which has been shown to be useful in the treatment of mild to moderate congestive heart failure. Digitalis along with a diuretic in the postoperative period can be troublesome owing to the potential toxicity of digitalis while the patient has ongoing fluid and electrolyte shifts.

100. Which of the following steps is/are appropriate for a 65-year-old woman who develops atrial fibrillation with associated mild hypotension and rapid ventricular response following partial gastric resection?
A. Correction of electrolytes and blood chemistries.
B. Evaluation for possible myocardial infarction.
C. Treatment with intravenous lidocaine.
D. Attempt to limit the ventricular response with digitalis.
E. Immediate cardioversion.
Answer: ABD

DISCUSSION: When a patient develops postoperative atrial fibrillation following an extracardiac procedure, correction of the patient's blood chemistries and electrolytes is essential. The patient must also undergo evaluation for a possible myocardial infarction as the cause of the atrial dysrhythmia. The first rule in treatment is to slow the ventricular response and attempt to limit hemodynamic instability. Digitalis is effective in slowing down the ventricular response and thus improving the hemodynamic status of the patient. Lidocaine has little use in controlling atrial dysrhythmias but is very effective in decreasing ventricular ectopy. Immediate cardioversion is rarely indicated for new-onset atrial fibrillation. Only after correction of all underlying metabolic and electrolyte defects as well as an attempt at medical conversion and ventricular rate control is cardioversion recommended.

101. The damaging effects of cardiopulmonary bypass are, to a large degree, due to activation of the humoral amplification system. The humoral amplification system includes which of the following?
A. The coagulation cascade.
B. The fibrinolytic cascade.
C. Complement activation.
D. A and C.
E. A, B, and C.
Answer: E

DISCUSSION: Cardiopulmonary bypass stimulates a whole-body inflammatory response, and the concentrations of several inflammatory mediators (e.g., complement fraction C5a) have been associated with subsystem dysfunction following cardiopulmonary bypass. This inflammatory response is complex and has several arms, including the coagulation, fibrinolytic, and complement systems. Simply blocking one pathway is unlikely to completely prevent bypass-induced injury.

102. Adequate flow during cardiopulmonary bypass is best indicated by:
A. Systemic blood pressure of 90/50 mm. Hg.
B. Arterial PO 2 of 230 mm. Hg.
C. Mixed venous hemoglobin saturation of 78%.
D. Central venous pressure of 1 mm. Hg.
E. Plasma lactate value of 6 mg. per dl.
Answer: C

DISCUSSION: The purpose of cardiopulmonary bypass is to provide adequate circulation of blood to sustain aerobic metabolism. Oxygen consumption during bypass depends on bypass flow until a critical flow is attained. With higher flows there is no further increase in oxygen consumption (i.e., oxygen consumption becomes flow independent), and the mixed venous hemoglobin saturation increases. A mixed venous hemoglobin saturation of 78% indicates that bypass flow is above the critical level and that flow is adequate. The other variables do not ensure adequate bypass flow.

103. Which of the following does not typically occur during the first few minutes of cardiopulmonary bypass?
A. Interstitial fluid increases.
B. Blood flow becomes nonpulsatile.
C. Platelet count decreases.
D. Complement is activated.
E. Systemic vascular resistance falls.
Answer: A

DISCUSSION: Several events occur during the first few minutes of bypass. The tubing and oxygenator surfaces are coated by serum proteins that in turn activate platelets. This reduces the platelet count. The roller pump produces nonpulsatile flow, which is different from the usual pulsatile cardiac flow. Serum complement is activated by exposure of blood to the nonphysiologic surfaces of the pump-oxygenator, and systemic vascular resistance falls. Interstitial fluid accumulates during bypass; however, this occurs later during bypass.

104. Which of the following are physiologic benefits of intra-aortic balloon counterpulsation to the ischemic ventricle?
A. Preload reduction.
B. Afterload reduction.
C. Coronary blood flow enhancement.
D. Decreased ventricular end-diastolic pressure.
Answer: BCD

DISCUSSION: In general, preload relates to the volume of blood or fluid presented to the left ventricle. Although wall tension does increase with increased volume, Starling properties are called forth for added efficiency. Preload is controlled by volume status as well as capacity of the venous system. The effects of balloon counterpulsation on cardiac preload are minimal and secondary to other changes. As the balloon collapses in the aorta, the absence of the balloon volume, or “abyss,” creates a decrease in ventricular afterload. In effect this decreases ventricular wall tension, reducing myocardial oxygen consumption significantly. During counterpulsation, the intra-aortic balloon inflates in diastole, elevating coronary perfusion pressure significantly. Maximal coronary artery perfusion occurs in this part of the cardiac cycle. Thus, ischemic ventricles benefit especially from balloon pumping. The balloon pump does not directly decrease the left ventricular end-diastolic pressure. However, in ventricles failing from ischemia the combination of afterload reduction and improved coronary blood flow usually augments cardiac function, producing decreased cardiac filling pressure or left ventricular end-diastolic pressure.

105. Which of the following are the major indications for instituting intra-aortic balloon pumping?
A. Medically refractory angina.
B. Acute papillary muscle rupture.
C. Left main coronary artery lesion.
D. Ventricular failure after cardiac surgery.
E. PTCA failure.
Answer: ABDE

DISCUSSION: Medically refractory angina is one of the major indications for implementing the intra-aortic balloon pump. When intravenous nitroglycerin becomes ineffective at relieving chest pain or results in early hypotension, the balloon pump should be used in preparation for surgical revascularization or percutaneous angioplasty. By reducing left ventricular afterload, the pump reduces regurgitation into the left atrium. Thus, balloon counterpulsation is very helpful for treating patients with acute mitral insufficiency secondary to papillary muscle rupture. Patients should undergo valve surgical procedures emergently, as balloon pump support is only temporizing. The mere presence of a left main coronary lesion is not an indication for use of the balloon pump. In former years such pumps were inserted prophylactically before induction of anesthesia for coronary bypass surgery. Newer anesthetic techniques have largely obviated this; however, in the presence of a left main lesion and medically refractory angina the balloon pump should be used. The balloon pump is quite effective in helping to wean patients who have postcardiotomy left ventricular failure from cardiopulmonary bypass. This is one of the major uses of this device. The Emory University group was the first to expound on the efficacy of the balloon pump in stabilizing patients following percutaneous angioplasty failure. With the pump inserted, most patients can be transported to the operating room safely, many being stable enough to harvest an internal mammary graft instead of having to defer to the more accessible but less preferable saphenous vein.

106. Which of the following are the most frequent complications of intra-aortic balloon counterpulsation?
A. Stroke.
B. Limb ischemia.
C. Arrhythmias.
D. Aortic thrombosis.
Answer: B

DISCUSSION: Stroke rarely occurs secondary to intra-aortic balloon pump use. The balloon must be positioned well below the aortic arch vessels and never proximal to the left subclavian artery origin. Strokes have been reported from emboli being thrown retrograde from the balloon; however, this is very rare. Limb ischemia is one of the most frequent complications of balloon pumping. The combination of iliofemoral atherosclerosis and catheter luminal obstruction may impede distal flow. This may require catheter removal to re-establish flow. In 2% to 10% of patients, arterial reconstruction is necessary to repair balloon-related complications. Smaller catheters have helped prevent limb ischemia. Arrhythmias in general are not complications of balloon pumping. In fact, arrhythmias related to ischemia may be controlled by the balloon pump. Aortic thrombosis can occur very rarely with pump use. A more frequent occurrence is distal embolization with limb ischemia. Patients should be heparinized while the balloon catheter is in place. Following cardiac surgery heparinization is usually delayed for 12 to 24 hours.

107. Permanent artificial hearts are being developed that are electrically powered. Wireless techniques are used to transmit the electrical energy across the body wall using the principle of:
A. Infrared sensor.
B. Inductive coupling.
C. Thermionic coupling.
D. High-pressure liquid chromatography (HPLC).
E. Infrared spectroscopy.
Answer: B

DISCUSSION: Electrical energy can be transmitted across the body wall by tunnelling an electric wire; however, experience has shown that infection, starting at the skin line and burrowing deeper into the body, will occur over time. This infection can be delayed, but not stopped, by the use of a velour covering on the wire. Wireless electrical energy transmission was first used in clinical surgery by W.W.L. Glenn in the 1950s for powering pacemakers. The remarkable advances in electronics have facilitated this technique; however, the placement of the two coils parallel to one another (with the skin between), as opposed to interlocking as in an industrial transformer, reduces the efficiency of transmission from approximately 99% to 70%.

108. The following statements about the pneumatic artificial heart is/are correct:
A. It can support the circulation for over 1 year.
B. It may be complicated by infection or thromboembolism.
C. When further developed, it will be an ideal permanent heart substitute.
D. It is an ideal “bridge” for transplantation.
E. It can be implanted using techniques similar to those used for heart transplantation.
Answer: ABE

DISCUSSION: The pneumatic artificial heart was developed as a permanent cardiac substitute, but the need for two tubes to pass through the chest wall and the bulky power unit have relegated the pneumatic heart to short-term use as a bridge to transplantation. The heart is implanted using similar techniques as a heart transplantation. The presence of foreign surfaces and crevices make the device prone to thromboembolism and infection. Most surgeons feel that left ventricular support or biventricular assist pumps represent a better option for those patients with end-stage congestive heart failure who require use of a bridge device.

109. A cyanotic infant has echocardiographic evidence of a univentricular heart (UVH). The following is/are true:

a. The most common form of the disorder is a double-inlet right ventricle
b. To be classified as a ventricle, the chamber must receive at least half of an inlet valve
c. This infant is a good candidate for a Blalock-Taussig shunt
d. Optimal correction of UVH diverts all vena caval blood flow into the pulmonary arteries (Fontan procedure)
e. In the absence of pulmonic stenosis, UVH usually presents as congestive heart failure
Answer: b, c, d, e

Univentricular heart is defined by the connection of the atria to only one ventricular chamber, usually the left as a double inlet left ventricle. A chamber must receive at least half of an inlet valve to be considered a ventricle. The presentation of UVH depends on the pulmonary blood flow; if pulmonary stenosis is present there is increased cyanosis and the infant is a candidate for a Blalock-Taussig shunt. In the absence of pulmonic stenosis, pulmonary flow is excessive and the presentation is congestive heart failure. Optimal correction of UVH diverts all vena caval flow into the pulmonary arteries as the Fontan procedure.

110. A 9-year-old boy with hypertension has no palpable femoral pulses. Coarctation of the aorta is suspected. The following is/are true:

a. The most common associated abnormality is a bicuspid aortic valve
b. Chest radiograph is likely to show rib notching
c. The etiology is felt to be secondary to an inflammatory aortitis
d. In infancy, coarctation may present with a pink upper body and cyanotic lower body
e. “Paradoxical hypertension” seen after operative repair indicates residual stenosis from incomplete correction
Answer: a, b, d

Coarctation of the aorta occurs just distal to the origin of the left subclavian artery and results from contraction of ectopic tissue from the ductus arteriosus. The most common associated abnormality is a bicuspid aortic valve. Extensive collateral development involves the mammary and intercostal arteries producing rib notching on the chest radiograph. In infancy, flow to the lower body is from the ductus arteriosus before it closes, producing differential cyanosis. The “paradoxical hypertension” seen postoperatively is thought to relate to sympathetic nerve stimulation and does not reflect an incomplete repair.

111. A 48-year-old woman with episodic syncope has echocardiographic evidence of a mass in the left atrium. The following is/are true statement(s):

a. Transseptal puncture should be used for definitive diagnosis
b. If this is a primary cardiac tumor it is most likely to be malignant
c. If this is a myxoma attached to the atrial septum, the adjacent septum should be removed with it
d. In infancy, the most common cardiac tumor is a rhabdomyosarcoma
e. The most common primary malignant tumor of the heart is angiosarcoma
Answer: c, e

Primary cardiac tumors commonly arise in the left atrium and can present with dyspnea, syncope, congestive failure and systemic embolism. Transseptal puncture should not be used for diagnosis because of the risk of embolism. Most primary cardiac tumors are benign by a 3:1 ratio. The most common malignant tumor is the angiosarcoma. Myxoma is the most common benign tumor, but it can recur and the adjacent atrial septum should be resected with it. In infancy, the most common cardiac tumor is a rhabdomyoma.

112. A 2-month-old boy who appeared normal at birth has become cyanotic and is found to have a systolic ejection murmur over the pulmonic area and a boot-shaped heart on chest radiograph. The following is/are true:

a. Echocardiography alone is sufficient to confirm the diagnosis of Tetralogy of Fallot
b. Cyanotic spells may be appropriately treated by propranolol
c. The Blalock-Taussig shunt connects the right ventricle to the pulmonary artery
d. Increasing cyanotic spells is the most common indication for operation
e. Operative repair of right ventricular outflow obstruction is never extended across the pulmonic valve since intolerable pulmonary insufficiency would result
Answer: a, b, d

In this typical scenario for Tetralogy of Fallot, echocardiography can confirm the diagnosis with no need for cardiac catheterization. Cyanotic spells are treated by supplemental oxygen, sedation with morphine and a beta blocker such as propranolol. For palliative increase in pulmonary blood flow, the Blalock-Taussig shunt is utilized connecting the subclavian artery to the pulmonary artery. Increasing cyanosis and cyanotic spells are the most common indication for operative repair. To correct the right ventricular outflow obstruction in Tetralogy, a transannular patch may be required extending into the pulmonary artery. Fortunately the pulmonary valvar insufficiency that results is well tolerated in the absence of tricuspid insufficiency or ventricular dysfunction.

113. A 12-year-old boy is found to have an ejection systolic murmur over the aortic region with a precordial thrill and normal cardiac size on chest radiograph. The following is/are true:

a. A systolic ejection click would signify that the stenosis is supravalvar
b. In the absence of cardiomegaly, cardiac catheterization to measure the pressure gradient is necessary
c. Development of syncope would suggest an intracranial lesion
d. In valvar aortic stenosis a pressure gradient of 80 mmHg is an indication for operative repair regardless of symptoms
e. In membranous subvalvar aortic stenosis a pressure gradient of 40 mmHg is an indication for operative repair
Answer: d, e

In the patient with findings of aortic stenosis, a systolic ejection click is evidence that the obstruction is valvular. Cardiac size does not provide an indication of the severity of the stenosis and is frequently normal. The development of angina or syncope reflects inadequate cardiac output and signifies late-stage disease. A pressure gradient over 75 mmHg is an indication for operation in valvar aortic stenosis even if the patient is asymptomatic while a lesser gradient of 30 mmHg or more is considered sufficient for operative correction of membranous subvalvar stenosis.

114. Within 2 hours of birth, a baby girl is obviously cyanotic and chest radiograph shows the heart to appear like “an egg on its side.” The following is/are true:

a. The most common cause of cyanosis this early is transposition of the great vessels (TGV)
b. If TGV is present, echocardiography will show that the posterior vessel leaving the left ventricle is a pulmonary artery
c. If TGV is confirmed by echocardiography, cardiac catheterization has little to add
d. The EKG is helpful in making the diagnosis of TGV since it shows reversed dominance of the ventricles
e. To improve mixing of pulmonary and systemic circulations, prostaglandin should be used to increase pulmonary vascular resistance
Answer: a, b

TGV is the most common cause of cyanosis in the first week of life, and this diagnosis can be confirmed by echocardiographic demonstration of a posterior pulmonary artery attached to the left ventricle. Cardiac catheterization is useful to confirm the anatomy, detect other lesions, define the coronary anatomy and improve cardiac mixing by balloon atrial septostomy. The EKG is not helpful in the diagnosis of TGV since it shows only normal right ventricular dominance. Prostaglandin improves the mixing of the circulation by opening the ductus arteriosus and reducing pulmonary vascular resistance.

115. A one-year-old boy thought to have Tetralogy of Fallot is found on cardiac catheterization to have double-outlet right ventricle (DORV). The follow is/are true:

a. Spontaneous closure of the VSD is rare
b. Location of the VSD has little effect on the degree of cyanosis
c. Double outlet left ventricles do not occur
d. Coincidental aortic stenosis with DORV is not compatible with life
e. Doubly committed VSD refers to its relationship to the great vessels
Answer: a, e

In DORV, the location of the VSD affects the direction of flow of oxygenated blood and thus determines the degree of cyanosis. Fortunately, the VSD rarely closes since that would result in severe decompensation or death. Double outlet left ventricles occur but are less common than DORV. A number of other anomalies are associated with DORV including both valvar and subvalvar pulmonary and aortic stenosis. The VSD may be directed to either or both great vessels (doubly committed) or remote from them (noncommitted).

116. A 5-year-old girl is found on routine examination to have a pulmonic flow murmur, fixed splitting of P2 and a right ventricular lift. The following is/are true:

a. Cardiac catheterization is indicated if the chest film shows cardiomegaly
b. Radiology report of “scimitar syndrome” findings on the chest film would indicate need for an arteriogram
c. If the catheterization report is “ostium secondum defect,” at least one pulmonary vein drains anomalously
d. Measured pulmonary vascular resistance of 14 Woods units/m2 with an ASD mandates early repair
e. An ASD with Qp/Qs of 1.8 can be observed until symptoms occur
Answer: b

The findings suggest an atrial septal defect (ASD) that can be confirmed by 2D echocardiography eliminating the need for cardiac catheterization. The ostium secondum type defect is most commonly found, but it is the sinus venosus type that is associated with anomalous pulmonary venous drainage. In the scimitar syndrome, the anomalous pulmonary vein can be seen on a chest radiograph and, since these are associated with a hypoplastic lung that is supplied by an anomalous systemic artery from the aorta, an arteriogram is appropriate. An ASD with a significant left-to-right shunt as demonstrated by a Qp/Qs ratio in excess of 1.5 should be repaired. When the pulmonary vascular resistance is elevated above 10–12 Woods units/m2 the patient is not a candidate for repair due to fixed pulmonary hypertension.

117. A 2-month-old infant has EKG evidence of myocardial ischemia and echocardiography suggests anomalous origin of the left coronary artery from the pulmonary artery. The following is/are true:

a. Ischemia is due to perfusion of the myocardium with inadequately oxygenated blood
b. Selective coronary angiography should not be attempted because of the risk of myocardial infarction
c. Conservative treatment is preferred to allow the coronary artery to grow to a size that will allow bypass construction
d. If the infant deteriorates, ligation of the coronary at its origin is a viable option
e. The severity of the abnormality insures that it will always be detected in the first year of life
Answer: d

Anomalous origin of the left coronary artery from the pulmonary artery results in reverse flow in the coronary into the low-pressure system as a steal from the coronary circulation. If collaterals from the right coronary develop to allow adequate myocardial perfusion, the disorder is frequently not diagnosed until later in life when a murmur is heard. Selective coronary arteriography is appropriate to define the anatomy and operative repair is undertaken promptly. Ligation of the anomalous coronary can be lifesaving but leaves the child dependent on a single vessel and coronary bypass is preferred.

118. A 2-month-old boy is found to be in congestive heart failure manifested by tachypnea, tachycardia and diaphoresis with poor weight gain. The physical findings suggest a ventricular septal defect (VSD). Management should include:

a. Pulmonary artery banding
b. Urgent closure if a VSD is found on echocardiography
c. Medical treatment only with digitalis and diuretics
d. If a VSD is found, repair is unlikely to be possible because of elevated pulmonary vascular resistance
e. If a restrictive VSD is found, spontaneous closure is a possibility and operative repair should be delayed
Answer: c, e

Large VSDs present at 6–8 weeks of age when the normally elevated pulmonary vascular resistance falls, allowing an increase in the left-to-right shunt. Since roughly half of all VSDs undergo spontaneous closure, particularly with restrictive defects, the initial management is medical. The diagnosis is confirmed by echocardiography and cardiac catheterization. Advanced pulmonary vascular changes do not occur usually until 2 years of age and banding is only rarely indicated for palliation for multiple complex muscular VSDs.

119. A 1-year-old girl with dyspnea and poor feeding is found to be in congestive heart failure. Echocardiography shows an atrio-ventricular septal defect (AVSD). The following is/are true:

a. The second heart sound will show fixed splitting
b. Despite diagnostic echocardiography, cardiac catheterization is indicated to assess pulmonary artery resistance
c. Pulmonary artery banding is indicated to limit pulmonary flow and allow the child to grow
d. AVSD is classified according to the morphology of the anterior leaflet of the common A-V valve
e. Operative repair is best performed after 2 years of age
Answer: a, b, d

AVSD is a defect of endocardial cushion development which produces morphologic abnormalities of both AV valves and both atrial and ventricular septa. It is usually classified according to the morphology of the anterior leaflet of the AV valve. The pulmonary vascular resistance remains elevated in infancy delaying diagnosis and producing fixed splitting of the second heart sound. Cardiac catheterization is indicated to assess pulmonary vascular resistance, but pulmonary artery banding is no longer performed to protect the pulmonary bed. Instead, operative repair is made, preferably before the age of 6 months.

120. The child in the previous question undergoes cardiac catheterization confirming a VSD with Qp/Qs ratio of 2.0 and right ventricular systolic pressure half of systemic pressure. The following is/are true:

a. If aortic insufficiency is detected, the defect is likely to be subpulmonic in location
b. Finding aortic stenosis in addition to the VSD would be highly unlikely
c. The cath data indicate a restrictive type of VSD
d. If pulmonary vascular resistance falls with tolazoline administration, it is safe to close the VSD
e. Operative closure of VSDs is possible without ventriculotomy
Answer: a, c, d, e

The finding of aortic insufficiency in a patient with VSD suggests prolapse of the aortic valve due to a subpulmonic or supracristal defect. Associated aortic stenosis, mitral stenosis and coarctation are common with VSDs. The finding of a moderate left-to-right shunt and a right ventricular pressure well below systemic levels indicates a restrictive VSD. If elevated pulmonary vascular resistance is found, the ability to respond to a vasodilator like tolazoline indicates that the resistance is not fixed and operative repair is possible. Operative repair of VSDs is frequently possible via atriotomy or through the pulmonary artery.

121. A premature infant in respiratory distress is found to have a continuous “machinery” murmur over the precordium. The following is/are true:

a. The most likely diagnosis is coarctation of the aorta
b. If large pulmonary arteries are noted, a patent ductus is likely
c. To discriminate between a and b, prostaglandin administration can be used which will constrict the patent ductus arteriosus
d. If a ductus if found, operative repair should be delayed until the respiratory symptoms improve to reduce mortality rates
e. Normal ductus closure depends on increased oxygen saturation in the pulmonary artery
Answer: b, e

A continuous “machinery” murmur is characteristic of patent ductus arteriosus typically seen in the premature infant. Normal closure of the ductus is prompted by a fall in pulmonary vascular resistance that increases the left-to right shunt and oxygen levels from the aorta. Indomethacin can cause ductus closure by cyclooxygenase inhibition which decreases endogenous prostaglandins. Prostaglandin infusion would keep the ductus open. Operative closure can be done safely in even the smallest neonates and usually promptly relieves the respiratory distress.

122. A neonate in congestive heart failure has echocardiographic evidence of a single truncal vessel from which the pulmonary arteries arise, a VSD and truncal valvar stenosis. The following is/are true:

a. Natural history of this anomaly allows only 20% one-year survival
b. The most likely configuration of the truncal valve is bicuspid
c. Location of the pulmonary arteries minimizes the risk of pulmonary vascular obstructive disease (Eisenmengers)
d. Repair of the lesion requires an extracardiac conduit
e. Optimal timing of operative repair is at 6–12 months
Answer: a, d

The defect described is truncus arteriosus which carries an 80% one year mortality rate uncorrected. The truncal valve is most commonly tricuspid (65%) or quadricuspid (25%); least likely bicuspid (9%). The large left-to-right shunt makes these patients particularly likely to develop pulmonary vascular obstruction (Eisenmenger’s syndrome). Operative repair requires detachment of the pulmonary arteries which are reconnected to the right ventricle by an extracardiac conduit, and the optimal timing for repair is within the first 6 months of life.

123. A neonate in respiratory distress has echocardiographic evidence of hypoplastic left heart syndrome (HLHS). The following is/are true:

a. Initial management should include prostaglandin infusion
b. Ventilatory adjustment should maintain PaCO2 at approximately 40 mmHg
c. Survival depends on sustained patency of the ductus arteriosus
d. Cardiac transplantation for HLHS requires inclusion of the donor aortic arch
e. Reconstruction for HLHS converts the pulmonary artery into the main outlet for a functional single ventricle (Norwood)
Answer: a, b, c, d, e

The neonate with HLHS has a severely underdeveloped left ventricular and aortic arch and is dependent on patency of the ductus which is facilitated by prostaglandin infusion. Ventilator adjustment to reduce supplemental oxygen and maintain PCO2 of 40 mmHg avoids excessive pulmonary flow. The options for treatment include cardiac transplantation which requires a donor aortic arch and reconstruction by the Norwood procedure which converts the pulmonary artery into the main outlet for a functional single ventricle.

124. A 52-year-old man with known aortic stenosis develops angina pectoris and has a single episode of syncope. The following is/are true:

a. Onset of angina indicates concomitant coronary artery disease independent of valvular lesion
b. Percutaneous aortic balloon valvuloplasty should be considered since it has generally favorable results
c. Patient is not an operative candidate since heart failure has not occurred
d. A measured transvalvular pressure gradiant > 50 mmHg would be an operative indication
Answer: d

The ventricular hypertrophy which accompanies aortic stenosis increases oxygen demand while mechanical forces increase resistance to perfusion, resulting in ischemia. Only one half of these patients with angina have coronary artery disease. Percutaneous balloon valvuloplasty of the aortic valve has high complication and recurrence rates. Any such patient with symptoms has an indication for operations as would the patient with a transvalvular gradiant > 50 mmHg.

125. The patient in the previous question with AI progresses to profound heart failure requiring medical management. The following is/are true:

a. Perperal vasdilators are contraindicated
b. The inta-aortic balloon pump can be used to improve cardiac output
c. Furosemide and nitroglycerin would be appropriate
d. Valve replacement is necessary
Answer: c, d

Peripheral vasodilators are key to the treatment of AI favoring peripheral blood flow. The intraaortic pump is contraindicated because diastolic augmentation worsens aortic regurgitation. Both furosemide and nitroglycerin would be of value to treat the failure, but the most effective treatment requires replacement of the valve.

126. A 42-year-old woman has noted progressive exercise intolerance and fatigability. Examination discloses an opening snap in the mitral area suggestive of mitral stenosis. The following is/are true:

a. Critical mitral stenosis is defined as an orifice area reduced to 2 cm2
b. With a fixed mitral orifice, the change from sinus rhythm to atrial fibrillation has little effect on cardiac output
c. Mural thrombi and thromboembolism are directly related to the presence of atrial fibrillation
d. Depressed cardiac output is usually due to depressed myocardial contractility
Answer: c

Normal adults have a 4–6 cm2 mitral orifice and reduction to 2 cm2 is mild stenosis while reduction to 1 cm2 is considered critical mitral stenosis. Even with a fixed orifice, the onset of atrial fibrillation reduces cardiac output by 20%. Mural thrombi and thromboembolism are directly related to the presence of atrial fibrillation. Mitral stenosis spares ventricular function, and the loss of cardiac output is from decreased preload.

127. Concerning valvular heart disease, the following is/are true:

a. Mitral stenosis is the most common lesion
b. Of all cardiac valves, the aortic is the most anterior
c. Stenosis is the most common lesion of the aortic valve
d. Rheumatic heart disease is the most common cause of valve dysfunction
Answer: c, d

Aortic valvular stenosis is the most common type of valvular lesion followed by mitral stenosis. Anatomically, the pulmonic valve is the most anterior of the cardiac valves. Rheumatic heart disease is the most common cause of valve dysfunction and the most common cause of multivalvular disease.

128. A 47-year-old male with fatigue and cardiac failure has a high-pitched, decrescendo diastolic murmur along the left sternal border and an apical diastolci rumble. His blood pressure is 148/45 mmHg. The following is/are true:

a. Chest radiograph will show cor bovinum
b. The apical murmur is due to the Gallavardin phenomenon
c. A carotid shudder would be expected
d. Abdominal exam will show a pulsatile liver
Answer: a

This patient with aortic insufficiency has a volume loading strain on the heart which produces cor bovinum as dramatic enlargement. The apical murmur produced by turbulence with mitral forward flow mimics mitral stenosis and is called an Austin-Glint murmur. A carotid shudder occurs with aortic stenosis and a pulsatile liver is typical of tricuspid insufficiency.

129. Concerning the adaptation to cardiac valvular dysfunction, the following is/are true:

a. Severe heart failure is more likely from acute than chronic valvular dysfunction
b. Valvular dysfunction produces both volume and pressure afterload stress on the heart
c. Early cardiac dilation from valve dysfunction shifts the Frank-Starling curve to depress cardiac output
d. The LaPlace law predicts that wall stress decreases with increasing ventricular radius
Answer: a, b

Valvular dysfunction produces both volume and pressure overload representing afterload stress on the heart. Although cardiac reserves allow for gradual adaptation to chronic valvular dysfunction, acute dysfunction is less well tolerated and more likely to result in severe heart failure. The increase in diastolic filling which initially dilates the heart, shifts the Frank-Starling curve to improve ejection and cardiac output. The LaPlace law predicts that wall stress increases with increasing ventricular radius but is inversely related to wall thickness.

130. A 31-year-old male drug abuser presents with fever, chills and multiple bilateral lung abscesses. Right heart endocarditis is suspected. The following is/are true:

a. The organisms most likely responsible are gram-negative and fungal
b. The pulmonic valve is most likely to be affected
c. A negative echocardiogram is useful to exclude the diagnosis
d. Valve replacement is necessary if the native valve is excised to treat infection
Answer: a

The typical endocarditis in a drug-abuser involves fungal and gram-negative organisms which infect the tricuspid rather than the pulmonic valve. An echocardiogram is useful to confirm the presence of vegetations but it may overlook smaller ones so it cannot be used to exclude the diagnosis. Although valve replacement is usually preferable, the infected tricuspid valve can be excised without prosthetic replacement.

131. In the initial management of the patient in the previous question with suspected acute MI, the following is/are true:

a. Oxygen and lidocaine should be administered prophylactically
b. If chest pain persists, IV nitroglycerin should be used to limit infarct size
c. Ca-channel blockers are also of value to limit infarct size
d. Morphine IV can be used but has no therapeutic effect
Answer: b

Initial treatment during an early evolving MI should include oxygen, but lidocaine should be used only if arrhythmias occur. Nitroglycerin IV is of value to limit infarct size but not Ca-channel blockers which have no such benefit. By decreasing pain and anxiety, morphine IV has a significant therapeutic effect in decreasing myocardial oxygen demand.

132. Concerning the physiology of the coronary circulation, the following is/are true:

a. Under circumstances of increased oxygen demand by the myocardium, O2 extraction from arterial blood can increase
b. Coronary flow is maximal during systole
c. Adenosine is the most important metabolic regulator of coronary blood flow
d. Sympathetic nerve stimulation constricts coronary arteries despite the need for increased cardiac output
Answer: c, d

Since myocardium maximally extracts O2 from blood at rest, increased demand requires increased delivery. Systolic pressures compress intramyocardial vessels, so maximal coronary flow is during diastole. Adenosine, a breakdown product of ATP, is a vasodilator and the most important metabolic regulator of coronary blood flow. Although sympathetic nerves produce coronary vasoconstriction, the autoregulatory vasodilatory responses to increased myocardial demand overwhelm that effect.

133. True statement(s) concerning cardiac vascular anatomy include the following:

a. In 80%–85% of cases the posterior descending coronary artery (PDA) arises from the circumflex coronary artery
b. The PDA gives off the AV nodal artery
c. The great cardiac vein ascends along the right coronary artery to empty into the coronary sinus
d. Thebesian veins drain from only left and right ventricles
Answer: b

In 80%–85% of cases the circumflex coronary artery ends with branches to the left ventricle while the PDA originates from the right coronary in 80%–85% of cases. The PDA gives off the AV nodal artery and its occlusion can result in heart block. The great cardiac vein ascends along the left anterior descending coronary artery and the Thebesian veins drain all 4 chambers.

134. In the medical management of coronary artery disease, the following is/are true:

a. Nitroglycerin primarily dilates coronary arterioles
b. b-blocking agents act to reduce myocardial O2 demand
c. Ca-channel blocking agents reduce ventricular contractility
d. Ca-channel agents should not be used if there is an element of coronary vasospastic disease
Answer: b, c

Nitroglycerin primarily dilates venous capacitance vessels, but at higher doses can produce coronary and systemic arterial dilation. b-adrenergic blocking agents reduce myocardial O2 demand by decreasing heart rate and contractility. Ca-channel blocking agents reduce ventricular contractility, produce vasodilation and may protect myocytes. They are particularly effective for coronary vasospastic disease.

135. A 67-year-old man with documented acute MI progresses in 24 hours to cardiogenic shock. The following is/are true:

a. The mortality rate for cardiogenic shock after acute MI is increased more than 10 fold in comparison to no shock
b. Age, ejection fraction, MI size and previous MI serve as predictors of cardiogenic shock
c. Acute loss of more than 20% of myocardium frequently results in cardiogenic shock and death
d. Emergency revascularization is contraindicated for the MI patient in cardiogenic shock
Answer: a, b

Cardiogenic shock is unusual after acute MI but increases the mortality rate from 4% to 65%. All of the risk factors described plus a history of diabetes mellitus can predict cardiogenic shock. The volume of myocardium lost acutely that is associated with shock is 40%. Recent studies suggest that emergency coronary bypass can be used within 18 hours of shock to reduce the mortality rate to 7%.

136. A 52-year-old man with chest pain and tachycardia has ECG evidence of an acute MI. The following is/are true:

a. Thrombolytic therapy should be considered immediately since the benefit is greater the earlier it is given
b. Of the drugs available, recombinant tPA produces better results than SK or APSAC although it is more expensive
c. Thrombolytic therapy requires catheterization for intracoronary administration
d. Addition of heparin and antiplatelet drugs produces no incremental benefit
Answer: a

Thrombolytic therapy for acute MI is of significant value in reducing mortality with benefit related to early administration. Although rtPA can produce higher coronary patency rates, the results of treatment are no better than with SK or APSAC. Thrombolytic drugs were initially given intracoronary but can be used effectively when given systemically IV. There is an added benefit from heparin and antiplatelet drugs to prevent rethrombosis.

137. Following repair of an abdominal aortic aneurysm, a 66-year-old man develops severe chest pain, diaphoresis, bradycardia and hypotension. The following is/are true:

a. The electrocardiogram is most likely to show a prominent Q in lead 3 if this is an MI
b. If Q wave is present, the infarct is subendocardial rather than transmural
c. Creatine kinase measurement alone is diagnostic of MI
d. Since bradycardia rarely occurs with MI, another diagnosis should be considered
Answer: a

Pain is the most common complaint in patients with myocardial infarction although 20%–25% are asymptomatic. Inferior MIs involving the right coronary frequently have parasympathetic activity with bradycardia, hypotension and a prominent Q wave in lead 3. The presence of a Q wave indicates a transmural MI which can be confirmed by measurement of the specific isoenzyme for cardiac tissue (CK-MB) since creatine kinase can be elevated non-specifically after stroke or operation.

138. A 70-year-old woman with intractable angina pectoris undergoes cardiac catheterization for possible mechanical intervention. She prefers PTCA to open correction. The following is/are true:

a. A long symmetric lesion in the left main coronary artery would be appropriate for PTCA
b. Multiple obstructive lesions in the same artery would be a contraindication to PTCA
c. A focal lesion in the left anterior descending coronary artery where the vessel is 1 mm in diameter would allow PTCA
d. Successful PTCA for a simple lesion carries a recurrent stenosis risk of less than 10%
Answer: b

The ideal lesion for PTCA is focal symmetric stenosis in an epicardial vessel. However, it is relatively contraindicated for significant disease in the left main coronary, for multiple obstructive lesions in the same artery, and for vessels less than 2 mm in diameter. Restenosis rates of 20% to 40% occur within the first 4–6 months after successful dilation for simple lesions.

139. A 78-year-old patient who is a candidate for CABG is concerned about the risks/benefits of the procedure. The following is/are true:

a. Operative mortality in patients > 70 years is more than double that of younger patients
b. If the patient is a woman, the risk is higher than it would be for a man
c. A previous CABG procedure increases the complexity and complication rate, but does not alter mortality rate
d. Results are better if there is ischemic cardiomyopathy than if there is hibernating myocardium
Answer: a, b

Operative mortality for patients > 70 years was 8% in the CASS study as compared to 3% in younger patients. For reasons not entirely clear, the risk of CABG is higher in women than in men. Reoperative procedures carry a higher operative mortality due to technical difficulties, more advanced disease, and less complete revascularization. Congestive heart failure is a major determinant of poor surgical outcome, but the results are better when there is viable myocardium (hibernating) than when there is irreversible ischemic cardiomyopathy.

140. Four days after a transmural MI, a 74-year-old man develops hypotension and congestive heart failure. The following is/are true:

a. An intra-aortic balloon pump should be used and cardiac catheterization performed
b. If the infarct was posterior, this is most likely due to a ventricular septal defect
c. Pulmonary wedge pressure tracing of prominent V waves without an O2 step-up suggests papillary muscle rupture
d. Operative repair of a post MI VSD should be delayed to allow strengthening of the myocardium to hold sutures
Answer: a, c

Both ventricular septal defect (VSD) and ruptured papillary muscle occur from 3–5 days post-MI and should be managed by intra-aortic balloon pump, decreasing afterload and cardiac catheterization for diagnosis. A VSD is most likely in an elderly hypertensive female who has sustained an anterior transmural MI; posterior MIs typically lead to papillary muscle rupture which is diagnosed by prominent V waves on pulmonary wedge pressure tracing. Survival rate for both of these complications is improved by early rather than late repair.

141. A 52-year-old woman with chest pain is considered for coronary arteriography on the basis of her risk factors. The following is/are true statement(s):

a. All patients with typical anginal symptoms should have coronary arteriography
b. Atypical patients with borderline positive stress tests should have arteriography
c. Patients who require valve procedures do not require arteriography
d. Patients in refractory heart failure awaiting cardiac transplantation should have coronary arteriography
Answer: b

Patients with typical angina and ECG changes should have angiography only if they are refractory to medical management and/or a candidate for revascularization. Patients with atypical signs and symptoms should have angiography to confirm or exclude the diagnosis. Patients with valve disease and risk of coronary artery disease should have angiography but patients awaiting cardiac transplantation are not candidates for revascularization and do not require coronary angiography.

142. The patient in the previous question is found to have disease unsuitable for PTCA. Concerning operative revascularization (CABG) the following is/are true:

a. CABG is more effective than medical treatment for relieving angina and improving physical work capacity
b. In CABG for unstable angina, there is no difference in late outcome between stable and unstable cohorts
c. For CABG, the most common arterial graft is the left internal mammary artery
d. Long term patency is improved when arterial grafts are used but there is no difference in the early mortality rate
Answer: a, b, c

Randomized studies show that CABG is more effective than medical therapy for relieving angina, improving physical work capacity and improving overall quality of life. When CABG is used for unstable angina, the initial complication and mortality rates are higher than for stable angina, but the late outcomes are similar. Use of arterial grafts for CABG has increased with the left internal mammary artery used most commonly; when at least one mammary artery is used, the early mortality rate is improved.

143. In the workup of a 45-year-old man with suspected coronary artery disease, the following is/are true:

a. Thyroid tests are included to rule out hyperthyroidism
b. Typically positive stress ECG would show elevated ST segments
c. Dipyridamole is a useful adjunct to thallium scanning as it increases coronary perfusion pressure
d. Persisting defects on thallium scan indicate reversible myocardial ischemia
Answer: a

Diagnostic studies for coronary artery disease should detect risk factors such as diabetes mellitus, hyperlipidemia and hyperthyroidism. The stress ECG typically shows downward sloping ST segment depression. Dipyridamole is a coronary artery vasodilator that reduces systemic and coronary perfusion pressures. The persisting thallium scan defect reflects irreversibly scarred myocardium.

144. Following successful thrombolytic treatment of the patient in the previous question, he develops recurrent chest pain in 24 hours. The following is/are true:

a. Rethrombosis is most likely and thrombolytic therapy alone should be repeated
b. The problem could have been prevented by early elective catheterization and PTCA
c. Patient has an indication for catheterization and PTCA if single vessel disease is found
d. Findings of multivessel disease at catheterization would indicate need for operative bypasses
e. If operative bypass is deemed necessary, there should be a 30-day delay to allow myocardial healing
Answer: c, d

After thrombolytic therapy for acute MI, angina recurs in 30%–35% and is an indication for cardiac catheterization and mechanical intervention to prevent infarct extension. Prophylactic catheterization, however, has not been found to provide benefit. If the findings at catheterization show limited disease treatable by PTCA, then it should be performed. But if multivessel disease or unfavorable anatomy is found, operative bypass should be carried out early since results are best within 30 days of the MI.

145. A 59-year-old male has undergone successful CABG with 4 grafts constructed but remains in low cardiac output (< 2L/min/m2) postoperatively. The following is/are true:

a. An inotropic drug should be used initially to increase cardiac output
b. If low cardiac output persists despite optimal physiological and pharmacological support, a balloon pump (IABP) should be inserted
c. Decreased cardiac filling pressures suggest the possibility of cardiac tamponade
d. When IABP is used, the balloon is inflated during diastole
Answer: b, d

Initial efforts to improve cardiac output should include correction of poor oxygenation or acidosis and optimization of rhythm, preload and afterload before an inotropic agent is used. If low cardiac output persists despite physiological and pharmacological support, an IABP should be inserted. It improves coronary artery perfusion by counterpulsation during diastole. Cardiac tamponade is heralded by increased cardiac filling pressures, narrowed pulse pressure and pulsus paradoxus.

146. A 42-year-old asymptomatic attorney undergoes a routine exercise test which is reported positive for myocardial ischemia. The following is/are true:

a. This is a rare event since less than 5% of patients with coronary artery disease (CAD) are asymptomatic with exercise
b. Such a patient could progress to heart failure from ischemic cardiomyopathy
c. Typical angina pectoris is promptly relieved by rest or relaxation
d. Dyspnea on exertion can represent an angina equivalent
Answer: b, c, d

As many as 25% of CAD patients found by exercise testing are asymptomatic. Progressive coronary obstruction in these patients can produce heart failure from ischemic cardiomyopathy. Typical angina is relieved promptly by rest or relaxation. Ischemic reductions in ventricular contractility and compliance can produce dyspnea on exertion as an angina equivalent.

147. A 52-year-old man develops postoperative supraventricular tachycardia to a rate of 180/min. and hypotension. The following is/are true:

a. Since a heart rate of 180/min should be tolerated at his age, the hypotension must have another cause
b. A vagal maneuver that breaks the tachycardia suggests atrial flutter as the etiology
c. Atrial overdrive pacing should be tried for paroxysmal atrial tachycardia (PAT)
d. Verapamil IV should be used for rate control
e. Cardioversion is preferred for patients on digoxin
Answer: c, d

A tachyarrhythmia over 150 beats/min can produce hypotension and myocardial ischemia and demands urgent therapy. Vagal maneuvers may break PAT but are not usually effective for atrial flutter or fibrillation. Atrial overdrive pacing should be attempted for PAT or atrial flutter. Verapamil is the most effective approach to rate control for supraventricular arrhythmias, but cardioversion of patients on digoxin should be undertaken cautiously since they are prone to ventricular tachycardia.

148. A 77-year-old man with a healed transmural myocardial infarction has a medically refractory ventricular arrhythmia. The following is/are true:

a. Direct current catheter endocardial ablation has a high likelihood of success.
b. If the arrhythmia is inducible at EP study, there is an indication for operative intervention.
c. A recent MI would be a contraindication to operation
d. Ventricular failure would be a contraindication to operation
e. Monomorphic ventricular tachycardia is least amenable to surgical resection.
Answer: b, c, d

After catheter ablation, only 25% of patients remain free of ventricular arrhythmia off of drug therapy. If the arrhythmia is inducible at EP study and the patient is an acceptable risk, with a myocardial scar he has an indication for operation. Both recent MI and ventricular failure are contraindications to operation. Monomorphic ventricular tachycardia is the arrhythmia most amenable to surgical resection.

149. A 68-year-old man suffers sudden cardiac death (SCD) but is resuscitated and brought to the hospital for evaluation and treatment. The following is/are true:

a. The most likely cause of SCD is ventricular arrhythmia
b. There is 30–40% chance of recurrent SCD in one year
c. Empiric antiarrhythmic drug therapy improves survival
d. An inducible ventricular tachyarrhythmia at EP study carries a favorable prognosis
e. If a ventricular aneurysm is found with arrhythmia, aneurysm resection is adequate treatment
Answer: a, b

Ventricular arrhythmias cause 75% of SCD, while 25% are due to acute MI. There is a 30–40% chance of recurrent SCD in one year. An inducible ventricular tachyarrhythmia carries a poor prognosis with < 50% five year survival from SCD unless it can be abolished. Empiric antiarrhythmic drug therapy does not improve survival. Aneurysmectomy alone is not adequate therapy for arrhythmias associated with aneurysms since the arrhythmia usually originates in adjacent mechanically stressed myocardium.

150. The following is/are true concerning the anatomy of the conduction system:

a. There is no special conduction path from the sinoatrial (SA) to the atrioventricular (AV) node
b. The blood supply to the AV node is from the anterior descending coronary artery
c. The only normal muscular connection between atria and ventricles is the bundle of His
d. The aortomitral continuity is the only area where supraventricular accessory pathways cannot occur
e. The sinus node artery arises from the right or circumflex coronary artery
Answer: a, c, d, e

The SA node is located at the junction of the superior vena cava and the right atrial appendage and receives its blood supply from the right or circumflex coronary artery. There is no special conduction path between SA and AV nodes. The bundle of His is the only normal atrioventricular muscle connection but abnormal pathways can occur anywhere except the area known as the aortomitral continuity. The blood supply to the AV node is from the posterior descending coronary artery.

151. The following is/are true concerning the physiology of arrhythmias:

a. A physical or electrical stimulus causes sodium fast channels and calcium slow channels to open
b. During the effective refractory period, only the slow calcium channels are closed
c. Rapid repolarization follows potassium egress from the cell
d. Extracellular hypokalemia increases sodium channel size increasing automaticity
e. Catecholamines increase outward potassium flow from myocytes
Answer: a, c, d

Physical or electrical stimuli cause sodium fast channels and calcium slow channels to open. During the effective refractory period, both slow calcium channels and fast sodium channels are closed and the myocardium cannot be excited. Then potassium channels reopen, allowing potassium out, and rapid repolarization occurs. Extracellular hypokalemia increases transmembrane potassium gradient and sodium channel size increasing automaticity. Catecholamines decrease outward potassium flow from myocytes enhancing automaticity.

152. A 72-year-old man has had several episodes of ventricular tachycardia and is a candidate for electrophysiological (EP) study. The following is/are true:

a. The goal of the EP study is either sustained or non-sustained ventricular tachycardia
b. Patients with less than 5 repetitive complexes in response to stimulation are considered noninducible
c. An induced reentry from ventricular stimulation is not necessarily pathological
d. Microreentry arrhythmias are typical after myocardial infarction
e. Macroreentry arrhythmias are typical of myocardial ischemia
Answer: a, b

For arrhythmias of ventricular origin, the EP study goal is either sustained or nonsustained ventricular tachycardia. Patients with less than five repetitive complexes in response to stimulation are considered noninducible. Ventricular reentry does not occur in normal myocardium, so all reentrant arrhythmias are pathological. Macroreentry arrhythmias are typical after myocardial infarction, while microreentry arrhythmias are typical of myocardial ischemia.

153. A 29-year-old male with supraventricular tachyarrhythmias is suspected to have Wolff-Parkinson-White (WPW) syndrome. The following is/are true:

a. Electrophysiologic studies (EPS) will require catheters in or at the right atrium, His bundle, right ventricle and coronary sinus
b. Pacing for EPS uses stimuli twice the diastolic threshold
c. The anomalous conducting bundle (Kent) is found in the right free wall if the coronary sinus catheter records the earliest atrial activity during reciprocating tachycardia
d. If the atrial catheter records the earliest activity during tachycardia, the bundle of Kent is located in the left free wall
e. If neither left or right bundle-branch block prolong the VA interval, the anomalous bundle is in the septum
Answer: b, e

For supraventricular arrhythmias, EPS requires catheters placed in the right atrium and ventricle, coronary sinus and His bundle. A programmable stimulator is used for stimuli that are twice the diastolic threshold and 2 msec in duration. When the coronary sinus catheter records the earliest activity during reciprocating tachycardia, the bundle of Kent is in the left free wall while it is in the right free wall if the earliest activity is in the atrial catheter. When neither left or right bundle-branch block prolong the VA interval, the bundle is in the septum.

154. A 62-year-old woman whose arrhythmia is noninducible at EP study has depressed LV function without aneurysm. The following is/are true:

a. If her arrhythmia is ventricular tachycardia, she is not a candidate for an Automatic Implantable Cardiac Defibrillator (AICD) since it only recognizes fibrillation
b. If an AICD is appropriate, it offers a 50% improvement in mortality compared to drug therapy
c. Poor ventricular function is a contraindication to AICD implantation
d. AICD should not be used for patients awaiting cardiac transplantation
e. AICD can provide antitachycardia pacing as well as defibrillation
Answer: b, e

The AICD is capable of recognizing ventricular tachycardia as well as fibrillation and can provide antitachycardia pacing, low or high-energy defibrillation or some combination. It offers a 50% improvement in mortality with 95% freedom from SCD at 5 years after implantation. Neither poor ventricular function nor pending transplantation are contraindications to AICD implantation.

155. A 27-year-old surgery resident has had multiple episodes of supraventricular tachycardia (SVT) and on EP study is felt to have WPW syndrome. The following is/are true:

a. The pathophysiology of WPW is a single bundle of Kent
b. Dangerous ventricular responses in WPW are due to the shorter refractory period of the accessory pathway
c. Identification of the accessory pathway of WPW is an indication for its interruption
d. Approximately half of the patients who have successful division of accessory pathways demonstrate VA block postop
e. Both radiofrequency catheter and surgical ablation offer excellent results with low morbidity
Answer: b, d, e

The pathophysiology of WPW is the Kent bundle of which 10–20% are multiple rather than single. The shorter refractory periods permit rapid and dangerous ventricular responses to atrial flutter or fibrillation. In 0.25% of the population, accessory pathways of WPW can be identified, but in the absence of a history of SVT, they have a normal life expectancy. Approximately half the patients who have successful division of accessory pathways demonstrate VA block postop. Both radiofrequency catheter and surgical ablation offer excellent results with low morbidity and the catheter technique is less costly.

156. In the pharmacological management of cardiac arrhythmias, the following is/are true:

a. Membrane-stabilizing local anesthetics (Class 1) act via sodium channel blockage
b. Class 1 drugs also shorten the refractory period
c. b-blocking drugs (Class 2) block the sympathetic nervous system but not circulating catecholamines
d. Bretylium and other Class 3 drugs inhibit potassium influx into cells
e. Calcium channel blockers (Class 4) directly affect the SA and AV nodes
Answer: a, d, e

Class 1 drugs are local anesthetics that act via sodium channel blockade, and lengthen the refractory period. Class 2 b-blocking drugs inhibit both the sympathetic nervous system and circulating catecholamines. Class 3 drugs inhibit potassium influx into cells and Class 4 drugs affect slow channel-dependent pacemaker tissue (SA and AV nodes).

NeuroSurgery MCQ

2008-09-06T19:06:00.000-07:00

1. Which of the following are true about the history of neurosurgery?
A. The history of trepanation dates back to the Neolithic period.
B. The earliest known writing dealing with surgical topics is the Ebers papyrus.
C. The writings of Hippocrates contain the first recorded descriptions of trepanation.
D. The three key developments that were necessary to permit successful intracranial and intraspinal surgery were anesthesia, asepsis, and the concept of localization of different functions in different areas of the nervous system.
E. Victor Horsely of London was the first surgeon to specialize in neurosurgery.
Answer: ACDE

DISCUSSION: Many skulls from the Neolithic period have been found, some of which contain cranial defects with evidence of bone healing, indicating that these individuals underwent trepanation during life and survived the operation. The earliest known writing dealing with surgical topics is the Edwin Smith papyrus. In the works of Hippocrates is the first written account of trepanation. During the second half of the nineteenth century, general anesthesia was introduced and the principles of asepsis were developed. These steps were important for all areas of surgery, including neurosurgery. In addition, it became recognized that certain areas of the nervous system were especially important for certain neurologic functions and that intracranial and intraspinal abnormalities might be localized by the history and neurologic examination findings, thus providing a more specific target for neurosurgical exploration through the small bony openings to which surgeons were restricted at the time. Victor Horsley of London was the first surgeon to prepare himself specifically for surgery of the nervous system and to concentrate his efforts in that area.

2. The neurosurgeon who has had the most profound influence on the development of neurosurgery is:
A. Fedor Krause of Germany.
B. William Macewen of Scotland.
C. Harvey Cushing of the United States.
D. Egas Moniz of Portugal.
E. Goeffrey Jefferson of England.
Answer: C

DISCUSSION: Harvey Cushing (1869–1939) laid the groundwork for much of what is done in neurosurgery. For example, he standardized operative procedures and introduced many techniques and instruments that are still in use. He also made careful and detailed studies of intracranial tumors and established their classification. By his own multifaceted career and through his many students from around the world he influenced the development of neurosurgery to a degree not equaled before or since.

3. Which of the following conditions can be evaluated by magnetic resonance imaging (MRI)?
A. Stroke is suspected in a patient with a cardiac pacemaker.
B. Computed tomography (CT) shows a skull base tumor.
C. A coma patient with CT-demonstrated subarachnoid hemorrhage and an aneurysmal clip.
D. A patient with intractable complex partial seizure.
E. A lung cancer patient whose plain film of the lumbar spine shows a compression fracture of the L2 vertebral body.
Answer: BDE

DISCUSSION: MRI has proved to be a better modality than CT for evaluation of disease of the central nervous system (CNS), such as diseases at the base of the skull (particularly the sellar and cerebellopontine angle cistern regions) and for most tumors, white matter disease (e.g., multiple sclerosis), early stroke, congenital abnormalities, vascular malformations, and spinal disease. New techniques of MRI such as fast spin echo (FSE) pulse sequence have been developed to detect mesial temporal sclerosis, which is the most common cause of intractable complex partial seizure. Differentiating pure compression fracture from metastatic disease of the vertebral bodies in a patient with known primary cancer is also possible by new MRI technique; however, for patients with certain types of metal (pacemaker, surgical clip, or foreign body, which may move in the magnetic field and cause injury to the patient or significant artifacts) within the bodies, MRI is contraindicated.

4. Which of the following statements about neuroradiologic imaging modalities is/are correct?
A. Diffusion-weighted MRI can differentiate tumor from edema and identify the nonenhancing part of the tumor.
B. For evaluating the stenosis of the carotid bifurcation, MR angiography (MRA) is the most accurate imaging modality.
C. Myelography is still useful in detecting some diffuse spinal disease such as cerebrospinal fluid (CSF) seeding.
D. For evaluating the bony detail of patients with facial trauma, CT is a better imaging modality than MRI.
E. Decreased amount of N-acetyl aspartate (NAA) and increased amount of lactate can be shown in the MR spectroscopy (MRS) of a patient with acute stroke.
Answer: ACDE

DISCUSSION: Diffusion-weighted MR is a new development in MR applications and is sensitive to microscopic motion of water protons (Brownian motion). Initial applications have involved imaging of early stroke and neoplasia. Early evidence also suggests that diffusion-weighted imaging can differentiate tumoral edema from tumor and identify the nonenhancing part of the tumor. Doppler sonography, MRA, and CT angiography (CTA) are all useful for evaluating the stenotic condition of carotid bifurcation noninvasively. However, sonography is very operator dependent, and MRA commonly overestimates the degree of carotid stenosis resulting from the turbulence, dephasing at points of stenosis or irregularity. CTA obtained by spiral or helical CT has a good correlation rate with carotid angiography (92%). Conventional carotid angiography remains the most accurate imaging modality for evaluation of the stenosis of carotid bifurcation. Although CT and MRI have taken the place of myelography in evaluating neurologic diseases, it is still useful in detecting diffuse subarachnoid seeding, which may be difficult to identify on MRI. The bone detail and calcification are poorly identified on MR, so in a patient with facial trauma, CT is a better modality than MR. With MRS, metabolites within a selected region of interest (ROI) can be investigated, and spectral peaks that reflect the concentrations of the metabolite within the ROI can be obtained. The metabolites include lactate, neuronal marker (NAA), phosphorus metabolites, creatine, and choline. Reduction in the NAA level and elevation in lactate level could be noted in acute stroke.

5. Which of the following are true about intracranial tumors?
A. The most common location of brain tumors of childhood is the posterior cranial fossa.
B. With few exceptions, examination of the CSF is of no value in the diagnosis of an intracranial tumor.
C. Even the most malignant of primary brain tumors seldom spread outside the confines of the central nervous system (CNS).
D. The majority of astrocytomas can be cured surgically.
E. Primary neoplasms of astrocytic, oligodendroglial, or ependymal origin represent gradations of a spectrum from slowly growing to rapidly growing neoplasms.
Answer: ABCD

DISCUSSION: In children, brain tumors are more commonly situated below the tentorium than above it. In adults, the reverse is true. Cytologic examination of CSF may provide critical diagnostic information in a patient with meningeal carcinomatosis or subarachnoid spread of a primary brain tumor such as a medulloblastoma, but in most instances CSF examination is not of significant value. Furthermore, in a patient with a brain tumor lumbar puncture may be dangerous; it may promote brain herniation. If there has not been a surgical breach of the dura mater, primary brain tumors seldom spread to areas outside the intracranial and intraspinal compartments. Most gliomas, including astrocytomas, cannot be cured by surgical resection. The pilocytic astrocytoma of the cerebellum and the optic nerve glioma are exceptions to that rule. Neoplasms of astrocytic, oligodendroglial, or ependymal origin vary histologically along a spectrum from benign to malignant, with no sharp dividing line. Furthermore, even the most benign-looking ones tend to recur after surgical resection.

6. The intracranial tumor most likely to be encountered in a middle-aged man with the acquired immunodeficiency syndrome (AIDS) is:
A. Glioblastoma multiforme.
B. Ependymoma.
C. Meningioma.
D. Oligodendroglioma.
E. Lymphoma.
Answer: E

DISCUSSION: Primary intracranial lymphomas occur with increased frequency in patients who are immunocompromised, such as recipients of organ transplants and patients with AIDS.

7. Patients who have survived a subarachnoid hemorrhage from a ruptured intracranial aneurysm are at risk for:
A. Rehemorrhage.
B. Cerebral artery vasospasm.
C. Ischemic stroke.
D. Hydrocephalus.
Answer: ABCD

DISCUSSION: Twenty percent of patients who suffer a subarachnoid hemorrhage from a ruptured intracranial aneurysm experience a second hemorrhage in the ensuing 2 weeks. Following subarachnoid hemorrhage, the patient is at risk for developing vasospasm, an idiopathic narrowing of the intracranial arteries that reside in the subarachnoid space. Vasospasm manifests clinically as cerebral ischemia or stroke. Blood within the subarachnoid space hinders normal flow and absorption of spinal fluid, frequently resulting in mild hydrocephalus. Although this hydrocephalus usually resolves in the days or weeks following the hemorrhage, in some cases it persists, necessitating a ventricular shunt.

8. Intracranial hemorrhages resulting from chronic arterial hypertension:
A. Most often originate in the basal ganglia.
B. Most often originate in the subarachnoid space.
C. Can present as an enlarging cerebellar mass.
D. Should not be treated surgically when they occur in the cerebellum.
Answer: AC

DISCUSSION: The most frequent site of a hypertensive hemorrhage is the basal ganglia. Blood may appear in the spinal fluid after the hemorrhage has dissected through the brain parenchyma into the cerebral ventricles. Approximately 10% of hypertensive hemorrhages originate in the cerebellum. Rapid removal of a cerebellar hemorrhage can be life saving.

9. The physician is most effective in treating:
A. Cerebral contusions.
B. Epidural hematomas.
C. Cerebral lacerations.
D. Hypoxia.
Answer: BD

DISCUSSION: The physician can do very little to repair damage incurred at the time of the head trauma such as cerebral contusions and lacerations. The physician's job is to thwart secondary injuries to the brain. Enlarging intracranial mass lesions, especially hematomas, are a common cause of secondary brain injury. Evacuation of an epidural, subdural, or intracranial hematoma can be life saving. Metabolic insults are another cause of secondary neurologic injury. Hypoxia, hypotension, and hypocapnia are avoidable secondary insults that should be treated at the scene of the accident. Unfortunately, a large percentage of trauma patients still arrive at the emergency room with metabolic abnormalities.

10. The evaluation of a comatose patient with a head injury begins with:
A. The cardiovascular system.
B. Pupillary reflexes.
C. Establishment of an airway.
D. Computed tomography (CT) of the brain.
Answer: C

DISCUSSION: The treatment of every comatose patient begins with an assessment of the patient's respiratory system, followed shortly thereafter with an assessment of the patient's cardiovascular system. The unconscious patient's normal protective pharyngeal reflexes are compromised, making mechanical airway obstruction and aspiration pneumonia common events. Hypotension, secondary to intra- or extracorporal hemorrhage, is deleterious to the patient's cerebral injury. Neurologic assessment is undertaken only after the patient's respiratory and cardiovascular status are secured.

11. An epidural hematoma:
A. Is usually arterial in origin.
B. Is usually accompanied by a skull fracture.
C. Should be suspected only in comatose patients.
D. Can be diagnosed from a brain CT scan.
Answer: AB

DISCUSSION: An epidural hematoma is a blood clot situated between the skull and the dura. Epidural hematomas are usually arterial in origin and most often are secondary to hemorrhage from the middle meningeal artery. Approximately 90% of adult patients with an epidural hematoma have a concomitant skull fracture. Such skull fractures are much less common in children under the age of 2 years. The epidural hematoma is best diagnosed before transtentorial herniation and the development of third cranial nerve palsy (“blown pupil”). The outcome of therapy is directly related to the patient's level of consciousness before surgery. The clinical diagnosis of an epidural hematoma is rarely confirmed by brain CT.

12. Which of the following statements is/are true?
A. Cranial osteomyelitis most frequently arises from the spread of bacteria through the bloodstream from an infection elsewhere in the body.
B. Subdural empyema is ordinarily treated by administration of antibiotics without the need for surgical drainage.
C. Bacterial meningitis may lead to the development of hydrocephalus.
D. A bacterial brain abscess commonly presents as a mass lesion of the brain, without systemic signs of infection such as fever or leukocytosis.
E. Bacterial brain abscesses are difficult to visualize by CT.
Answer: CD

DISCUSSION: Cranial osteomyelitis can arise from hematogenous spread, but more often it results from direct spread from an infected paranasal sinus, inoculation by a penetrating object, or operative infection of a craniotomy bone flap. Subdural empyema ordinarily cannot be brought under control with antibiotics alone, and it does require surgical drainage. One of the sequelae that can follow bacterial meningitis is hydrocephalus, which is usually due to the obliteration of subarachnoid spaces and interference with CSF reabsorption. A brain abscess, per se, is not ordinarily accompanied by systemic signs of infection; these can be present if the patient also has meningitis or an active infection elsewhere. CT, especially after intravenous administration of a contrast agent, is an excellent way to demonstrate a brain abscess.

13. Complete excision of a brain abscess used to be the preferred method of treatment, and it is still performed occasionally today. Most commonly, now, a brain abscess is treated by:
A. Systemic antibiotic administration.
B. Aspiration and drainage of the abscess through a small opening in the skull.
C. Injection of antibiotics into the abscess.
D. Aspiration and drainage of the abscess plus systemic antibiotic administration.
E. Marsupialization of the abscess.
Answer: D

DISCUSSION: In the past, the preferred treatment of a brain abscess was total surgical excision. Now that such abscesses can be followed closely by CT, aspiration and drainage is usually employed, at least initially, to reduce the mass effect, provide information about the pathogens, and lower the risk of intraventricular rupture while the abscess is treated by systemic administration of antibiotics.

14. Which of the following statements are true?
A. Extradural neoplasms are usually benign.
B. A typical type of intramedullary tumor is a meningioma.
C. An intradural extramedullary neoplasm is ordinarily treated by a combination of surgical resection and radiotherapy.
D. Extradural neoplasms are usually malignant.
E. A hemangioblastoma is a benign intramedullary tumor that has the potential for surgical cure.
Answer: DE

DISCUSSION: Extradural neoplasms are usually malignant, the most common type being a metastasis to a vertebra from a primary carcinoma elsewhere in the body. A meningioma is an extramedullary tumor arising from the meninges surrounding the spinal cord rather from within the cord itself. Most intradural extramedullary neoplasms are benign tumors (meningiomas, neurofibromas, schwannomas) that are treated by surgical excision without postoperative radiotherapy. Despite its name, the hemangioblastoma is a benign tumor. It typically arises within the spinal cord and can be cured if it is completely removed surgically.

15. Which of the following statements about intraspinal dermoid and epidermoid tumors and lipomas are true?
A. They are benign lesions.
B. They can be found within the spinal subarachnoid space.
C. They can be found within the spinal cord.
D. They are most common in the lumbosacral area.
E. They are at times associated with spinal dysraphism.
Answer: ABCDE

DISCUSSION: Intraspinal dermoid and epidermoid tumors and lipomas are benign lesions that can be found within the subarachnoid space or the spinal cord, or both. They are most common in the lumbosacral area. Dermoid and epidermoid tumors can be associated with spinal dysraphism and in particular with a dermal sinus tract that opens onto the back, usually in the lumbosacral region. Lipomas are also associated with spinal dysraphism, at times in the form of a lipomyelomeningocele with a tethered spinal cord.

16. Which of the following statements are true?
A. The usual symptomatic lumbar disc herniation occurs in a posterolateral direction.
B. Approximately 95% of lumbar disc herniations occur at the L5–S1 or L4–L5 level.
C. Sciatica is a term used to denote pain felt along the distribution of the sciatic nerve.
D. Weakness of dorsiflexion of the foot is a mechanical sign of a lumbar disc herniation.
E. X-ray films of the lumbosacral spine are obtained to demonstrate the presence and location of a lumbar disc herniation.
Answer: ABC

DISCUSSION: Most symptomatic lumbar disc herniations do occur in a posterolateral direction, impinging on the overlying nerve root. About 95% of lumbar disc herniations occur at the L5–S1 or L4–L5 level. Approximately 4% occur at the L3–L4 level, and less than 1% at the L2–L3 or L1–L2 level. Sciatica is a term used to refer to pain along the course of the sciatic nerve. A ruptured lumbar disc typically causes low back pain and ipsilateral sciatica. The mechanical signs of a lumbar disc herniation include paravertebral muscle spasm, lumbar scoliosis, tenderness over one or more of the lower lumbar spines, limitation of low back motion, limitation of straight leg raising, and a positive popliteal compression test. Weakness of dorsiflexion of the foot is a neurologic sign, not a mechanical sign. Plain x-ray films of the spine do not demonstrate the presence and location of a lumbar disc herniation except in the rare instance of a calcified disc herniation. Myelography, CT, or MRI is needed to visualize the herniated disc.

17. A right-sided disc herniation at the L5–S1 level typically may cause:
A. Low back pain and right sciatica.
B. Weakness of dorsiflexion of the right foot.
C. A diminished or absent right ankle jerk.
D. Diminution of sensation over the medial aspect of the right foot, including the great toe.
E. Weakness of dorsiflexion of the left foot.
Answer: AC

DISCUSSION: A lumbar disc herniation at the L5–S1 or L4–L5 level typically causes low back pain and ipsilateral sciatica. If a ruptured L5–S1 disc causes weakness, it ordinarily involves plantar flexion of the ipsilateral foot. Although a diminished or absent ankle jerk can be caused by either an L5–S1 or an L4–L5 disc herniation, it is more common with the former. The L5–S1 disc herniation ordinarily affects the S1 nerve root, which supplies the lateral aspect of the foot, including the small toe.

18. Which of the following statements are true?
A. A symptomatic cervical disc herniation usually occurs in an anterolateral or anterior direction and can be removed by a surgical approach through the front of the neck.
B. Cervical spondylosis represents a combination of degenerative disc disease and osteoarthritis in the cervical spine.
C. The joints of Luschka are the main spinal facet joints.
D. The term cervical myelopathy refers to pain and/or neurologic dysfunction in the distribution of one or more cervical nerve roots.
E. Full neck extension frequently accentuates the neck and arm pain of a patient with a cervical disc herniation.
Answer: BE

DISCUSSION: A symptomatic cervical disc herniation usually occurs in a posterolateral direction, although a directly posterior (central) herniation may occasionally occur. The posterolateral herniated disc can be removed by either a posterior or an anterior approach, but the anterior approach is preferred for the central herniation because the surgeon can remove the ruptured disc without manipulating (and possibly injuring) an already compromised spinal cord. Cervical spondylosis represents a combination in the cervical spine of degenerative disc disease and osteophyte formation (including that from osteoarthritis of the apophyseal joints and the joints of Luschka). The cervical spine contains the joints of Luschka, which are not present elsewhere in the spine. These joints, one on each side of the disc, are separate from the more posteriorly situated facet joints (apophyseal or interpedicular joints). The term cervical myelopathy refers to dysfunction of the cervical portion of the spinal cord. Pain and/or neurologic dysfunction in the distribution of one or more cervical nerve roots is termed cervical radiculopathy. Neck movement, especially extension, often intensifies the neck and arm pain of a patient with a cervical disc herniation.

19. A 36-year-old man developed neck and left arm pain. He noted paresthesias in the left index and long fingers. He was found to have weakness of the left triceps muscle and a diminished left triceps jerk. His left-sided disc herniation is most likely to be at:
A. C3–C4.
B. C4–C5.
C. C5–C6.
D. C6–C7.
E. C7–T1.
Answer: D

DISCUSSION: This patient has all of the neurologic components of the most common cervical disc syndrome, that caused by a herniation at the C6–C7 level with compression of the C7 nerve root.

20. Which of the following statements are true?
A. The fascicles in a peripheral nerve divide and recombine along their course.
B. Neurapraxia is a type of nerve injury in which the nerve is still in continuity but individual axons are disrupted.
C. Recovery from neurotmesis requires surgical repair.
D. Axonal sprouting begins 1 to 2 months after transection of a peripheral nerve.
E. The patient's age influences the rate and success of nerve regeneration.
Answer: ACE

DISCUSSION: Fascicles within a peripheral nerve do divide and recombine along their course, forming funicular plexuses. If a segment of a nerve is removed and the remaining ends are reapproximated, the fascicles will not match exactly. In neurapraxia (first-degree nerve injury) anatomic continuity of the axons is preserved, but there is selective demyelination. Surgical repair is not necessary. Recovery does not depend on regeneration and occurs within days or weeks. With neurotmesis there is significant disorganization in the nerve or actual disruption of its continuity, which precludes recovery without surgical repair. Axonal sprouting ordinarily begins 10 to 20 days after transection of a peripheral nerve. The patient's age affects the rate and success of nerve regeneration: the younger the patient is, the faster and more complete is the recovery.

21. Which of the following statements are true?
A. The Hoffmann-Tinel sign localizes the level of a nerve injury.
B. Causalgia is a term used to denote the etiology of pain.
C. Secondary repair of a lacerated nerve 3 to 8 weeks after injury has several advantages.
D. A surgeon who finds at delayed (3 to 8 weeks) exploration that a clinically nonfunctioning nerve is in continuity should resect the injured portion of the nerve and suture together the ends.
E. If a nerve is found to be disrupted at delayed (3 to 8 weeks) exploration, the surgeon should find the two ends of the nerve and suture them together.
Answer: C

DISCUSSION: The Hoffmann-Tinel sign identifies the most distal point of small nerve fiber regeneration. As nerve regeneration progresses, this point moves farther away from the level of the nerve injury. Causalgia is a specific severe pain syndrome that may accompany a partial injury to a mixed peripheral nerve. As compared with primary repair, the extent of damage to a nerve can be better assessed and the correct amount trimmed off, with a secondary repair 3 to 8 weeks after the injury; the epineurium and perineurium are stronger and can be sutured more easily; optimal operating room conditions can be arranged; and there is no time for wallerian degeneration (i.e., the involved neurons are capable immediately of regenerating new distal segments, and the regenerating axons can penetrate the repair site before a significant amount of scar forms). If a clinically nonfunctioning nerve is in continuity when it is explored some weeks after the initial injury the surgeon may find it helpful to stimulate the nerve electrically proximal to the injury and to look distally for evidence of muscle contraction or transmission of nerve action potentials. If there is no evidence of transmission across the area of injury, the injured portion of the nerve should be excised and the cut ends sutured together. If there is transmission across the area of injury, surgical treatment should be limited to external neurolysis. A disrupted nerve should be reapproximated surgically, but only after each end has been trimmed back to healthy fascicles. The trimmed nerve ends must not be under tension when they are sewn together.

22. Which of the following lesions is not one of the cutaneous stigmata of occult spinal dysraphism?
A. Midline lumbar capillary hemangioma.
B. Focal hairy patch over the thoracolumbar spine.
C. Dermal sinus located above the midsacrum.
D. Midline subcutaneous lipoma.
E. Café-au-lait spot over the thoracolumbar spine.
Answer: E

DISCUSSION: Café-au-lait spots are not a feature of spina bifida occulta. The other four skin features all may be associated with significant intradural pathology and warrant further investigation, most commonly with magnetic resonance imaging (MRI). A dermal sinus tract that overlies the coccyx is a pilonidal sinus and is not likely to be associated with intradural pathology.

23. Myelomeningoceles are congenital malformations of the spinal cord. Which of the following findings are not commonly associated?
A. Hydrocephalus.
B. Chiari II malformation.
C. A midline dorsal spinal mass easily noted at birth.
D. Skin, bone, and dural defects superficial to the neural placode.
E. Mandatory urinary incontinence.
Answer: E

DISCUSSION: Myelomeningoceles are usually associated with hydrocephalus and the Chiari II malformation. The myelomeningocele sac is a midline dorsal spinal mass associated with defects in the skin, bone, and dura overlying the neural placode, and the sac is readily apparent at birth. Although the innervation of the bladder is dysmorphic, the majority of patients can achieve social urinary continence through the use of clean intermittent bladder catherization.

24. Which of the following signs does Horner's syndrome include?
A. Ptosis.
B. Facial hyperhidrosis.
C. Miosis.
D. Exophthalmos.
E. Mydriasis.
Answer: AC

DISCUSSION: Horner's syndrome is due to loss of sympathetic innervation to the head and neck and includes ptosis, anhidrosis, miosis, and the appearance of enophthalmos. The pupil is small owing to loss of the tonic dilating effect of the sympathetics in the presence of continued parasympathetic activity. There is sympathetic innervation to Muller's muscle in the upper lid. Sympathetic nerves supply the sweat glands. It commonly follows stellate ganglion resection and involves removal of the T1 cord level sympathetic outflow.

25. Cordotomy results in which of the following?
A. Contralateral loss of pin appreciation.
B. Vagal instability.
C. Contralateral loss of temperature appreciation.
D. Ipsilateral loss of pin and temperature appreciation.
E. Contralateral loss of two-point discrimination.
Answer: AC

DISCUSSION: Cordotomy results in a lesion of the spinothalamic tract, which is a crossed pathway carrying signals for pain and temperature.

26. Surgical therapy for epilepsy should be considered in patients with:
A. Seizures poorly controlled with antiepileptic medications.
B. A single epileptic focus.
C. Seizures arising from multiple areas of cerebral cortex.
D. Seizures arising within the cortical motor strip.
Answer: AB

DISCUSSION: Because seizure surgical procedures can never be guaranteed to alleviate seizures, it is only undertaken when medical therapy fails to control the patient's seizures at doses that do not produce intolerable side effects. Most surgical procedures are aimed at removing a single epileptogenic area of cerebral cortex and are rarely employed in patients with multiple areas of epileptogenic cortex. Eloquent areas of cerebral cortex such as those subserving speech or hand functions generally are not intentionally resected in an attempt to achieve seizure control.

27. The epileptogenic area of cerebral cortex is localized by:
A. Direct identification.
B. Observing the patient's seizures.
C. Electroencephalography.
D. Visualizing cortical abnormalities on cerebral imaging studies.
Answer: BCD

DISCUSSION: Since the exact anatomy of an epileptogenic focus remains obscure, the focus of the patient's seizures is determined by concordance of the clinical manifestations of the seizures, abnormalities demonstrated by cerebral imaging, and abnormalities demonstrated by electroencephalography.

28. Which of the following stereotactic procedures would be performed primarily to alter the function of the brain?
A. Stereotactic biopsy of a brain tumor in the right posterior thalamus.
B. Stereotactic radiotherapy of an arteriovenous malformation in the right ventrolateral thalamus.
C. Stereotactic radiofrequency lesion of the right ventrolateral thalamus for Parkinson's disease.
D. Stereotactic craniotomy for excision of arteriovenous malformation in the right posterior thalamus.
Answer: C

DISCUSSION: The biopsy of a lesion, radiotherapy treatment of an arteriovenous malformation, and excision of an arteriovenous malformation are all procedures for structural lesions of the brain that can be imaged by either CT or MRI. These structural lesions may or may not cause neurologic changes, but the treatment directed at them is intended principally to keep lesion-induced damage from increasing (for example, with the development of hemorrhage). On the other hand, the thalamus is expected to have a normal structural appearance and function in Parkinson's disease, when the neurochemical abnormality is located in the substantia nigra and the striatum (caudate and putamen). Thus, a lesion is made in the thalamus principally to affect the function of the brain, altering a normal component of one of the motor circuits to compensate for the changes in the other parts (i.e., the basal ganglia).

29. What is the critical difference between frame-based and frameless stereotactic procedures?
A. The use of digitized imaging studies such as CT and MRI.
B. The use of rendered three-dimensional images and a three-dimensional digitizer.
C. Rigid fixation of the patient's head to the operating room table.
D. The presence of a lesion in the brain on digitized imaging studies.
E. The absence of a lesion in the brain on digitized imaging studies.
Answer: B

DISCUSSION: Frame-based and frameless procedures both use digitized imaging studies as the basis for converting the scan coordinate system into a treatment coordinate system. Both types of procedures also require rigid fixation of the patient's head to the operating room table and can be performed in the presence or absence of a lesion. The critical difference is the use of a rendered, three-dimensional image and the three-dimensional digitizer, which together allow the alignment to be generated between the patient's imaging studies and the patient; this alignment occurs in frame-based stereotactic procedures because of the imaging study performed after the frame is applied.

30. A 54-year-old patient with a history of successful renal transplantation is hospitalized with a diverticular abscess. Surgical exploration and drainage of the abscess with a Hartmann’s procedure is eventually required. Although the patient’s septic appearance resolves, the patient complains of severe headache and altered mental status is observed. A grand mal seizure follows. Which of the following statement(s) is/are true concerning this patient’s management?

a. An intracranial epidural abscess is the likely diagnosis
b. A bacterial brain abscess secondary to hematogenous spread from the pericolonic infection is the likely diagnosis
c. The abscess expected in this case is usually solitary
d. Appropriate parenteral antibiotic treatment should be sufficient in this high risk patient.
e. Despite aggressive surgical and medical management, mortality rates associated in this patient may exceed 30%
Answer: b, d, e

A brain abscess is a purulent lesion of brain tissue, beginning as a focal infection, usually in the white matter surrounded by a typical inflammatory response. Brain abscesses usually are secondary to focal infection elsewhere. Abscesses that develop by direct intracranial extension are usually solitary and are typically found in the frontal and temporal lobes. Multiple brain abscesses that develop in the septic patient are often related to bacterial endocarditis, pneumonia, and diverticulitis. Abscess formation is frequent among patients with compromised immunity either from an underlying illness or during pharmacologic immunosuppression (i.e., during organ transplantation). Signs and symptoms of brain abscess are related to its mass effect. Headache, focal neurologic deficits, and impaired mentation are often noted. There may be little or no evidence of infection and the patient may be afebrile. Seizures may occur. Intracranial epidural abscesses are quite uncommon and are usually caused by a local extension of osteomyelitis or by hematogenous spread from a distant suppurative focus.
In cases of early abscess formation or high surgical risk, medical therapy alone with the appropriate parenteral antibiotic may be sufficient. The most effective therapy is drainage of the purulent material with simultaneous administration of appropriate intravenous antibiotics. Although needle aspiration may be successful, craniotomy with evacuation and removal of the abscess wall may be necessary. Surgical drainage reduces the mass effect, thereby reducing the most critical and dangerous aspect of the infection. It also allows accurate bacteriologic analysis. Despite aggressive surgical and medical management, mortality rates associated with brain abscess approach 40%, especially in the malnourished, chronically debilitated, or immunosuppressed patient.

31. All intracranial nervous system tumors can be malignant in behavior due to their location. Which of the following tumor(s) is/are usually considered to be histologically benign?

a. Astrocytoma
b. Meningioma
c. Schwannoma
d. Medulloblastoma
e. Craniopharyngioma
Answer: b, c, e

Astrocytomas arise from the glial (stromal or supporting) cells of the brain. These tumors are infiltrative and rarely can be totally excised. High-grade astrocytomas (grades III and IV) are the most common primary intracranial tumor constituting 25% of all intracranial tumors and 50% of all gliomas. For the most part meningiomas are benign tumors that arise from the arachnoid layer of the meninges occurring in the fourth through sixth decades of life. Meningiomas can occur in a variety of sites and together constitute about 17% of intracranial tumors. The treatment for meningiomas is surgical, however, total resection is uncommon, frequently resulting in recurrence. Malignant histologic appearance of meningiomas is far less common than a benign appearance. Schwannomas are benign tumors that arise from the Schwann cells that surround axons as they leave the CNS by way of the cranial nerves. Schwannomas constitute 8% of all intracranial tumors and are almost twice as common in females as males. Medulloblastomas are part of the primitive neuroectodermal classification of brain tumors. They are thought to arise from primitive cells of the cerebellum, most likely the external granular layer. They constitute 8% of all gliomas. Two-thirds of medulloblastomas occur in children, with the average age of onset being 14 years. They commonly metastasize throughout the subarachnoid space by way of the CSF and are rarely found outside the CNS. Treatment involves aggressive surgical removal of the tumor followed by radiation of the brain. Chemotherapy is commonly used as well. Craniopharyngiomas are histologically benign and arise from nests of squamous cells within the pituitary gland. They may be found in the intrasellar or suprasellar locations but are always along the craniopharyngeal canal. Over 50% occur in the first two decades of life. Although craniopharyngiomas can be cured with surgical removal or controlled with radiation, many of these histologically-benign tumors cannot be removed safely.

32. A 54-year-old physician with a history of lung cancer presents after a grand mal seizure with a several month history of increasing headaches. Which of the following statement(s) is/are true concerning this patient?

a. Lung cancer as well as breast, kidney, testicular and colon cancer are the most common primary sites to metastasize to the brain
b. A symptomatic, solitary metastatic brain lesion should be removed if surgically accessible
c. If excision is complete, no further chemo-or radiation therapy is indicated
d. Symptoms of cranial nerve palsies, radiculopathies and nuchal rigidity are suggestive of meningeal carcinomatosis
e. Cytologic examination of CSF is almost always positive with meningeal metastasis
Answer: a, b, d

The percentage of intracranial tumors representing metastases approach 25%. Malignant cells invade the CNS hematogenously and tend to lodge at the grey and white matter junction. Although any malignancy has the potential to metastasize to the brain, the most common primary sites are the lung, breast, kidney, testes, colon, and skin. The presenting symptoms are determined by the site or sites of the metastases. Symptoms commonly include headache, mental status changes, seizures and hemiparesis. In general, a symptomatic solitary lesion that is surgically accessible should be removed if the patient has at least a six-month life expectancy. Surgery should not be undertaken for multiple lesions or in patients who are severely afflicted by their primary disease. Whole brain irradiation is almost always indicated after surgical resection. There is little evidence that chemotherapy plays a significant role. Tumor metastasis to the leptomeninges (meningiocarcinomatosis) is also common particularly in adults with lymphoma, breast, and lung cancer. Patients may present with cranial nerve palsies, radiculopathies, obstructive hydrocephalus. They often have signs and symptoms suggestive of meningitis. Analysis of the CSF is usually critical, often revealing increased opening pressure, elevated white blood cell count and protein levels, and a decreased glucose. Cytology should always be obtained, however it is not universally positive for malignant cells.

33. The management of a skull fracture is highly dependent on the type and location of the fracture. Which of the following statement(s) is/are true concerning skull fractures?

a. A simple nondepressed linear skull fracture is of no significant consequence
b. Most depressed skull fractures require surgery to elevate the depressed bone fragment regardless of neurologic status
c. Basal skull fractures involve the base of the calvarium and may be suggested by bruising about the eye or behind the ear
d. CSF rhinorrhea associated with a basal skull fracture requires prompt surgical exploration and repair of the defect
e. Prophylactic antibiotics are indicated in all basal skull fractures associated with CSF rhinorrhea or otorrhea
Answer: b, c

Skull fractures are classified according to whether the skin overlying the fracture is intact (closed) or disrupted (open or compound), whether there is a single fracture line (linear), several fractures radiating from a central point (stellate), or fragmentation of the bone (comminuted), and whether the edges of the fracture line had been driven below the level of the surrounding bone (depressed) or not. Simple skull fractures (linear, stellate, or comminuted nondepressed) require no specific treatment. They are, however, potentially serious and can be fatal if they cross major vascular channels in the skull, such as the groove of the middle meningeal artery or the dural venous sinuses. Depressed skull fractures often require surgery to elevate the depressed bone fragments. If there are no adverse neurologic signs and the fracture is closed, repair may be done electively. Basal skull fractures involve the floor of the calvarium. Bruising may occur about the eye (raccoon sign) or behind the ear (Battle sign), suggesting a fracture involving either the anterior or middle fossa, respectively. Any associated cerebrospinal fluid (CSF), rhinorrhea, or otorrhea should be treated expectantly. Traumatic CSF leaks typically stop within the first 7 to 10 days. Should a leak persist, lumbar CSF drainage can be implemented to seal the leak by lowering CSF volume and intracranial pressure. If this therapy fails, surgical exploration and oversewing of the defect with a facial patch graft is indicated. Less than 5% of patients actually require surgical repair. Prophylactic antibiotics are no longer used since prospective studies have failed to demonstrate any significant benefit from their use.

34. Which one or more of the following statement(s) is/are true concerning spinal cord injuries?

a. Incomplete spinal cord lesions may result in the Brown-Sequard syndrome which is manifest by contralateral loss of motor function and position-vibratory sensation with ipsilateral loss of pain and temperature sensation below the level of the injury
b. The presence of hypotension associated with a cervical spine injury following blunt trauma would suggest invariably the presence of blood loss in association with the neurologic injury
c. Cervical spine malalignment can almost always be reduced by skeletal traction
d. An indication for early operation following spinal cord injury is neurologic deterioration in a patient with initially incomplete cord lesion
e. The natural history of a cord injury in which some function is preserved immediately after the injury is progressive loss of function despite appropriate treatment
Answer: c, d, e

Injuries to the spinal cord can be either complete, resulting in total loss of function below the level of the injury or incomplete which may be manifest in the Brown-Sequard syndrome. This syndrome is manifested by ipsilateral loss of motor function and position-vibratory sensation with contralateral loss of pain and temperature sensation below the level of the injury. Anatomically, this presentation is explained by hemisection of the cord. In addition to the neurologic deficit, acute spinal cord injury is accompanied by many systemic responses. Blood pressure is generally low if the cord injury is above the T-5 level. Such an injury effectively denervates the sympathetic nervous system, which leads to increased venous capacitance and decreased venous return. The resulting hypotension is controlled by the administration of intravenous fluids.
The goals of treatment of a spinal injury are to correct spinal alignment, to protect undamaged neural tissue, to restore function to irreversibly damaged neural tissue, and ultimately to achieve permanent spinal stability. Reduction and immobilization of any fracture or dislocation must receive top priority to meet these objectives. Cervical spine malalignment can almost always be reduced by skeletal traction. Traction may be applied using skull tongs or halo apparatus. Both are seated percutaneously through the outer table of the skull while the patient is kept supine and immobilized. The indications for early operation on patients with spinal cord injury include the inability to close the fracture or dislocation satisfactorily by closed methods, neurologic deterioration in a patient with initially incomplete cord lesion, and severe compression of the spinal cord by an intraspinal mass shown on myelography or MRI. Either the anterior or posterior approach may be used, depending on the nature of the spine injury and the degree of instability. If cord function is preserved immediately after injury, additional function usually returns if the cord and spine are protected from secondary injury. Patients with complete injuries rarely recover function below the level of the lesion.

35. A 48-year-old man presents with chronic back pain with radiation into the buttock, posterior thigh, and calf. Which of the following statement(s) is/are true?

a. In the lumbar spine, more than half of clinical problems arise from L-2 to L-3 and L-3 to L-4 intervertebral discs
b. Imaging studies with CT or MRI followed by myelography is necessary for the diagnosis in most patients
c. Initially, medical management is indicated in all patients who do not have neurologic deterioration
d. Surgical treatment is reserved for the patient with acute or progressive neurologic deficit, chronic disabling back pain, or both
e. Anal sphincter muscle disturbances can be expected in most patients and are of no clinical significance
Answer: c, d

Herniated lumbar intervertebral discs often produce some degree of nerve compression. The severity of the syndrome depends on the degree of root compression. In the lumbar spine, more than 90% of clinical problems arise from the L-4 to L-5 and L-5 to S-1 intervertebral discs. Diagnosis is based on history of back pain usually with radiation into the buttock, posterior thigh, and calf at both levels. Pain may be exacerbated by coughing, sneezing, or straining. Bending and sitting accentuate the discomfort, whereas lying down characteristically relieves it. Thorough evaluation of back pain is necessary because of the multitude of causes for such symptoms. Plane films of the lumbosacral spine can identify congenital or bony changes. Disc space narrowing is an unreliable sign, however, of symptomatic disease since narrowing of the disc space can occur without clinical symptoms. Myelography can be diagnostic in symptomatic lumbar disc disease, but CT alone delineates the lesion in most cases. MRI has replaced myelography and CT at some centers in the workup of lumbar radiculopathy. With contrast, it can be extremely helpful in previously-operated cases.
Initially, medical treatment is indicated in all patients who do not have neurologic deterioration. Bed rest, local heat, analgesics, and skeletal muscle relaxants are usually effective within a few days. Physical therapy and limited exercise often help when the acute episode passes. With an aggressive conservative management, most patients improve sufficiently to return to full activity. Recurrent symptoms may be treated in a similar fashion, often successfully. Surgical treatment is reserved for a patient with acute or progressive neurologic function, chronic disabling pain, or both. The acute onset of weakness or sphincter disturbances constitute an emergency, demanding prompt diagnosis and early operation.

36. Which of the following statement(s) is/are true concerning intracranial aneurysms?

a. Over 85% of cerebral aneurysms occur in the carotid or anterior circulation
b. Most intracranial aneurysms are congenital
c. Up to 20% of patients with cerebral aneurysms have multiple aneurysms
d. Most patients with intracranial aneurysms present with signs and symptoms of subarachnoid hemorrhage with severe headache followed by neck stiffness and photophobia
e. Once the diagnosis of aneurysmal rupture is confirmed, surgery should be performed immediately
Answer: a, b, c, d

Most intracranial aneurysms are congenital, evolving and developing during life. They are typically found at the bifurcation of major vessels of the circle of Willis with over 85% occurring in the carotid or anterior circulation. Up to 20% of patients with aneurysms will have multiple aneurysms. Patients with intracranial aneurysms most commonly present with signs and symptoms of subarachnoid hemorrhage. In fact, 80% of nontraumatic subarachnoid hemorrhages are caused by aneurysm rupture. The patient notes a sudden severe headache commonly followed by neck stiffness and photophobia due to associated meningeal irritation caused by subarachnoid blood. Transient loss of consciousness may occur. Some patients may develop a focal neurologic deficit or become comatose due to acute rise in ICP.
The diagnosis of subarachnoid hemorrhage is usually made clinically and confirmed either by noting blood within the subarachnoid spaces on CT scan or finding bloody CSF with xanthochromia on a lumbar puncture. The CT scan should be obtained first since it spares the patient an LP and also eliminates the potential risk of brain-stem compression from herniation if an unsuspected mass lesion is present. Complete cerebral angiography is then used to identify and delineate the aneurysm and, at the same time, rule out multiple aneurysms or an associated arterial venous malformation. Once the diagnosis of aneurysmal rupture is confirmed, the patient is placed on a medical regimen to reduce the risk of rebleeding. This includes strict bed rest with the head elevated. Blood pressure is tightly controlled below 150 mm Hg systolic. Careful observation is necessary to watch for signs of raised ICP which may be attributable to delayed hydrocephalus. Anticonvulsants are started for seizure prophylaxis. The ultimate treatment of aneurysms is microsurgical dissection and obliteration, usually by placing a metallic clip on the aneurysm’s neck by way of a craniotomy. The timing of surgery depends on the clinical grade of the patient. Good grade (I and II) patients should undergo operation within 72 hours of rupture. Poor grade (III and IV) should continue intensive medical management until they improve to a lower grade because mortality is higher with higher grades. Surgically accessible unruptured aneurysms should be operated on electively to prevent rupture.

37. The severity of a brain injury reflects the result of both the primary injury and resulting complications constituting the secondary injury. Which of the following statement(s) concerning brain injury is/are true?

a. Increased intracranial pressure (ICP) contributes to secondary brain injury by reducing cerebral perfusion pressure producing cerebral ischemia
b. Intracranial hypertension is one of the most important factors affecting outcome for brain injury
c. In using the Glasgow Coma Scale (GCS), the higher the score, the poorer the neurologic status
d. Comatose patients who require emergent surgery for other injuries should have their ICP monitored
e. Corticosteroids are the first line treatment for elevation of ICP
Answer: a, b, d

Elevated intracranial pressure (ICP) contributes to secondary brain injury by reducing cerebral perfusion pressure which, by definition, is the difference between the mean arterial blood pressure and the cerebral venous pressure. For all clinically-relevant purposes, the cerebrovenous pressure is identical to ICP. Thus, when ICP increases and the mean arterial blood pressure remains stable, cerebral perfusion pressure decreases. When cerebral perfusion pressure falls below 70 mm Hg, cerebral blood flow is compromised, producing cerebral ischemia and compounding the primary injury with secondary insult. In studies of head injury mortality, intracranial hypertension appears to be one of the most important factors affecting outcome. For this reason, aggressive management to circumvent cerebral blood flow reduction and secondary injury is imperative. Initial clinical assessment is essential. Although extensive neurologic testing is limited in uncooperative or unresponsive patients, certain features of examination are crucial. The Glasgow Coma Scale (GSC) uses a numerically scored elevated eye-opening and motor behavior, both spontaneously and in response to stimulation. The higher the score generated in assessment, the better the patient’s neurologic status. This scale also provides useful information regarding the ultimate outcome of the head-injured patient. ICP monitoring may be indicated especially in patients with marked depression or deterioration in neurologic function. Comatose patients who require emergent surgery for other injuries should also be monitored, since frequent neurologic assessment is not possible during general anesthesia. The steps in management to prevent ICP elevation include elevation of the head to facilitate venous return. Sedation reduces posturing and reflexively combative activity which both worsen ICP. Hyperventilation keeps arterial carbon dioxide levels between 25 and 28 mm Hg and lowers cerebral blood volume and ICP. Mild dehydration with judicious sodium replacement and prompt treatment of inappropriate secretion of the antidiuretic hormone (SIADH) protects the brain from insult secondary to fluid overload. If ICP remains elevated despite these measures, mannitol, 0.5 to 1 g/kg and furosemide, 0.1 mg/kg can be used to reduce cerebral edema. Deep sedation with narcotics and even the use of paralyzing agents may be helpful. Corticosteroids are occasionally used, but have no proven benefit.

38. A 15-year-old boy is struck by a baseball in the side of the head. He briefly looses consciousness but quickly returns to a lucid state. Which of the following statement(s) is/are true concerning his subsequent course.

a. The initial neurologic finding may be dilatation of the ipsilateral pupil
b. If the patient has a normal neurologic examination at the time of emergency room assessment, he can be discharged safely to home
c. A head computed tomography (CT) scan should be performed regardless of the current neurologic examination
d. The likely mechanism of injury arises from a tear of a branch of the middle meningeal artery as it courses through a grove in the skull at the area of impact
e. If, after an initial lucid interval, a rapid progression to coma with fixed and dilated pupils and decerebration occurs, the most likely CT finding would be a subdural hematoma
Answer: a, c, d

Hemorrhage between the inner table of the skull and the dura mater most commonly arises from a tear of the middle meningeal artery or one of its branches that course through a grove in the lateral skull. Arterial bleeding strips the dura from the undersurface of the bone and produces still more bleeding because the small bridging veins from the dura to the skull are torn. The result is an epidural hematoma which may rapidly increase in size and compress the cerebral cortex. An epidural hematoma classically follows a blow to the head which causes a brief period of unconsciousness. After the patient regains consciousness, there may be a lucid interval during which there are no abnormal neurologic symptoms or signs. As the hematoma enlarges, hemispheric compression occurs. With time the medial portion of the temporal lobe is forced over the edge of the tentorium causing compression of the oculomotor nerve and subsequent dilatation of the ipsilateral pupil. Similarly, compression of the ipsilateral cerebral peduncle causes contralateral hemiparesis, which progresses to decerebrate posturing. Coma, fixed and dilated pupils, and decerebration is the classic triad suggestive of transtentorial herniation. Epidural hematomas are curable lesions, but the mortality rate remains high because the severity of the injury is often not recognized early. A patient may be seen during a lucid interval and discharged. Later, the patient becomes unconscious because of progressive brain compression by the expanding hematoma. Because of the danger of misdiagnosis, any patient with a history of a blow to the head leading to a period of unconsciousness should have a CT scan.

39. Which of the following statement(s) is/are true regarding peripheral nerve injuries?

a. Neuropraxia is temporary loss of function without axonal injury; structure damage does not occur
b. Axonotmesis is disruption of the axon and axon sheath associated with traumatic injury
c. Neurotmesis is disruption of the axon with preservation of the axon sheath which usually preserves sensory and motor function
d. Electromyography (EMG) is useful in the early assessment of nerve injuries
e. Regeneration in a peripheral nerve occurs at a rate of 1 mm/day, so improvement may not be obvious for many months
Answer: a, e

Peripheral nerve injuries may be categorized functionally. Neuropraxia is a temporary loss of function without axonal injury and structural damage does not occur. Axonotmesis is a disruption of the axon with presentation of the axon sheath. Wallerian degeneration of the distal axon fragment occurs. Stretched or prolonged compression causes this functional and structural loss. Regeneration of the proximal axon occurs, but functional recovery depends on the associated injuries, the amount of healthy proximal axon remaining after injury, and the age of the patient. Neurotmesis is disruption of both the axon and axon sheath with corresponding loss of function and is caused by transection of a nerve. Regeneration occurs, but function rarely returns to normal. Clinically, sensory motor changes correspond with the peripheral nerve involved. Detailed history and a precise neurologic examination can localize the site of injury with accuracy. EMG is not useful within the first three weeks of injury but is highly effective for monitoring the status of the degeneration and regeneration process that occurs later.
Regeneration in a peripheral nerve occurs at 1 mm/day (roughly 1 inch each month), so improvement may not be obvious for months. Factors that adversely affect the return of function include advanced age of the patient, proximal nerve injury, extensive nerve tissue loss, associated soft tissue injury, and mixed sensory motor function. Unfortunately, incomplete neurologic recovery is often the rule.

Urology MCQ

2008-09-06T19:02:00.000-07:00

1. The most ominous sign or symptom of urinary system disease is:
A. Urinary frequency.
B. Pyuria.
C. Pneumaturia.
D. Dysuria.
E. Hematuria.
Answer: E

DISCUSSION: While urinary frequency (voiding more than three to five times daily) or dysuria (painful voiding) may be a sign of malignant disease, they are more commonly associated with nonmalignant inflammatory disease, neurologic disease, or calculous disease of the urinary tract. Pyuria (pus in the urine) is most commonly associated with infection and not malignancy. Pneumaturia (air or gas in the urine) indicates a fistula between bowel and the urinary tract or infection by fermination in diabetic urine. Hematuria (blood in the urine) is most worrisome. While this may be produced by infection or by calculous disease, it is most commonly associated with malignant disease in the absence of associated signs or symptoms such as pyuria, frequency, and dysuria. Thus, of the ones mentioned, hematuria is the most ominous single sign or symptom.

2. A patient with acute urinary tract infection (UTI) usually presents with:
A. Chills and fever.
B. Flank pain.
C. Nausea and vomiting.
D. 5 to 10 white blood cells per high-power field (hpf) in the uncentrifuged urine specimen.
E. Painful urination.
Answer: E

DISCUSSION: Cystitis or infection of the bladder is the most common UTI. Lower UTI, or cystitis, is an infection in the bladder. Painful urination and frequency are the most common presenting complaints. Hematuria may occur, but is associated with painful urination and frequency. Flank pain, fever, chills, nausea, and vomiting usually occur only when the infection involves the kidney. An acute UTI is identified in unspun urine only when there are more than 10 leukocytes per hpf in the unspun urine. The normal urine may have as many as 10 WBC/per hpf without being infected.

3. Renal adenocarcinomas:
A. Are of transitional cell origin.
B. Usually are associated with anemia.
C. Are difficult to diagnose.
D. Are extremely radiosensitive.
E. Frequently are signaled by gross hematuria.
Answer: E

DISCUSSION: Renal adenocarcinomas arise from the renal tubular cells and not from the transitional cells that line the collecting system of the kidney. Although one fifth of all patients with renal cancer may present with anemia, the most common presenting symptom is hematuria, either gross or microscopic. Ultrasonography may confirm that a renal lesion is either cystic or solid but computed tomography (CT) is probably the most accurate imaging study for diagnosing the disease. Renal adenocarcinoma is little sensitive to current chemotherapeutic agents. Radiotherapy plays almost no role in the management of the primary tumor. Operation is the treatment of choice when the disease is confined to the kidney itself or when it has extended just outside the renal capsule. An operation has little effect once the disease is extended to adjacent structures or to regional lymph nodes.

4. Ureteral obstruction:
A. Is associated with hematuria.
B. Is associated with deterioration of renal function and rising blood urea nitrogen (BUN) and creatinine values.
C. Is commonly caused by a urinary tract calculus.
D. Usually requires open surgical relief of the obstruction.
E. Is usually associated with infection behind the obstruction.
Answer: C

DISCUSSION: Ureteral obstruction produces loss of renal function when there is only one renal unit and the ureter is obstructed or when obstruction is bilateral. Ureteral obstruction often is best identified by either intravenous pyelography (IVP) or retrograde pyelography, which allows one to identify the specific site of obstruction. Calculous disease is the most common cause of ureteral obstruction. Ureteral obstruction is not a surgical emergency that requires open surgical intervention, but it may be relieved by retrograde or antegrade passage of a double-J stent to bypass the obstruction, permitting orderly nonemergent identification of the cause of obstruction and selection of a treatment process.

5. Stress urinary incontinence:
A. Is principally a disease of young females.
B. Occurs only in males.
C. Is associated with urinary frequency and urgency.
D. May be corrected by surgically increasing the volume of the bladder.
E. Is a disease of aging produced by shortening of the urethra.
Answer: E

DISCUSSION: Stress urinary incontinence is seen principally in older females and is produced by pelvic floor relaxation with shortening of urethral length. The symptom of stress urinary incontinence is urinary leakage produced by an increase in intra-abdominal pressure, as with straining to lift or to laugh. Urgency and frequency are symptoms of urge incontinence, not stress incontinence. Stress incontinence classically is not seen either in males or in young females who have good pelvic floor support.

6. Which of the following is/are true of blunt renal trauma?
A. Blunt renal trauma and penetrating renal injuries are managed similarly.
B. Blunt renal trauma with urinary extravasation always requires surgical exploration.
C. Blunt renal trauma must be evaluated by contrast studies using either IVP or CT.
D. Blunt renal trauma requires exploration only when the patient exhibits hemodynamic instability.
E. Any kidney fractured by blunt renal trauma must be explored.
Answer: D

DISCUSSION: Blunt renal trauma should be explored. Only those who have gross hematuria need undergo contrast studies. Microscopic hematuria is no longer an indication for contrast evaluation. Patients who have blunt renal trauma need to undergo exploration only if they are hemodynamically unstable. Conservative management in the absence of hemodynamic instability is the current trend. All penetrating injuries should undergo exploration.

7. Carcinoma of the bladder:
A. Is primarily of squamous cell origin.
B. Is preferentially treated by radiation.
C. May be treated conservatively by use of intravesical agents even if it invades the bladder muscle.
D. May mimic an acute UTI with irritability and hematuria.
E. Is preferentially treated by partial cystectomy.
Answer: D

DISCUSSION: Carcinoma of the bladder is primarily of transitional cell origin, arising from the transitional epithelium that lines the bladder. It may be confused with an acute UTI by producing urgency, frequency, and hematuria. Bladder carcinoma may be treated conservatively using intravesical agents if the tumor is intraepithelial in origin and does not invade through the basement membrane. Neither radiation nor chemotherapy is the treatment of choice for disease that invades the muscle of the bladder. Partial cystectomy may be chosen only when the disease is focal and there are no mucosal changes in other parts of the bladder.

8. The major blood supply to the testes comes through the:
A. Hypogastric arteries.
B. Pudendal arteries.
C. External spermatic arteries.
D. Internal spermatic arteries.
Answer: D

DISCUSSION: Testes arise from portions of the wolffian bodies on the genital ridge close to the kidneys; therefore, the major blood vessels from the testes arises from the aorta just below the renal arteries and are termed the internal spermatic arteries. Secondary blood supply to the testes comes from the artery of the vas deferens, and a small branch from the epigastric artery termed the external spermatic artery forms during descent of the testes from the abdomen to the scrotum. The surgical importance of this phenomenon is that operations involving the region of the renal arteries may sacrifice the internal spermatic artery. If the two other arteries are intact, the testes will survive; however, if the patient has had a vasectomy and the artery of the vas has been sacrificed, there is a possibility of testicular atrophy, since the testicle will have to be totally dependent on the arterial supply derived from the small external spermatic artery.

9. Patients who have undergone operations for benign prostatic hypertrophy or hyperplasia:
A. Require routine rectal examinations to detect the development of carcinoma of the prostate.
B. Do not need routine prostate examinations.
C. Have a lesser incidence of carcinoma of the prostate.
D. Have a greater incidence of carcinoma of the prostate.
Answer: A

DISCUSSION: Patients who have undergone operations for benign prostatic hyperplasia or hypertrophy have had only the inner portion of the prostate removed, which consists of the periurethral glandular structures that give rise to hyperplasia and hypertrophy. The posterior segment of the prostate, which is compressed by the anterior (inner) portion, comprises the surgical capsule and is left behind. The posterior portion of the prostate gland is the most frequent site of origin of prostate cancer. There is no difference in the incidence of carcinoma of the prostate in patients with benign prostatic hypertrophy and those without benign prostatic hypertrophy or those who have and have not undergone operation for prostatic hypertrophy. Since prostate carcinoma can develop at any time in a patient's life, routine examinations and prostate-specific antigen assay are the most efficient methods of detecting this disease.

10. The male contribution to a couple's infertility is approximately:
A. 10%.
B. 25%.
C. 50%.
D. 75%.
Answer: C

DISCUSSION: In the United States of America it has been estimated that approximately 15% of couples have difficulty with conception. Adequate evaluation of the marital unit for infertility demands assessment of the male partner since infertile status may be attributed to the male as much as 50% of the time. A full evaluation of the male partner is important to avoid extended fruitless evaluation and management of the female partner when the male is infertile.

11. To maximize fertility potential, orchidopexy for cryptorchidism should be done before:
A. Age 15 years.
B. Age 12 years.
C. Marriage.
D. Age 2 years.
Answer: D

DISCUSSION: The testes are exquisitely sensitive to temperature; therefore there is progressive deterioration of testes that are not within the scrotum. Cryptorchid testes, whether they be in the inguinal canal, in an intra-abdominal position, or in an ectopic position, will undergo progressive spermatogenic failure, although adequate amounts of androgens may be produced and secreted. The timing of orchidopexy has been moved progressively backward, and now the recommendation is that orchidopexy should be accomplished before age 2 years, to maximize the possibility of production of spermatozoa of normal quantity and quality. In cases of unilateral cryptorchidism the matter of surgical exploration is less critical; however, to provide maximum potential for both testes, the earlier cryptorchidism is surgically corrected the better are the chances for normal spermatogenesis.

12. Within the age group 10 to 35 years, the incidence of carcinoma of the testis in males with intra-abdominal testes is:
A. Equal to that in the general population.
B. Five times greater than that in the general population.
C. Ten times greater than that in the general population.
D. Twenty times greater than that in the general population.
Answer: D

DISCUSSION: The incidence of carcinoma of the testis is greater in patients who have cryptorchidism, whether corrected or not; because of this, routine self-examination by patients who have undergone operation for cryptorchidism is important. For patients who have uncorrected intra-abdominal testes it is estimated that the incidence of the development of carcinoma of the testis in the age group 10 to 35 years is approximately 20 times greater than that for the general population. If cryptorchidism is diagnosed after the age of 10 to 12 years, orchiectomy may be the preferred treatment, since such testes rarely exhibit normal function, despite adequate scrotal placement, and put the patient at great risk for an intra-abdominal neoplasm that will be difficult to diagnose.

13. The appropriate surgical treatment for suspected carcinoma of the testis is:
A. Transscrotal percutaneous biopsy.
B. Transscrotal open biopsy.
C. Repeated examinations.
D. Inguinal exploration, control of the spermatic cord, biopsy, and radical orchectomy if tumor is confirmed.
Answer: D

DISCUSSION: If, after physical examination, and even scrotal ultrasound, a tumor of the testicle is still suspected, the appropriate surgical treatment is high inguinal exploration with control of the cord, delivery of the testicle onto a protected field, biopsy if necessary, and then orchiectomy at the level of the internal ring if tumor is confirmed. Transscrotal manipulations, whether they be percutaneous or open, are to be condemned because of the possibility of tumor spillage with the ultimate necessity for hemiscrotectomy to control local recurrence. Certainly, repeated examinations over a very short period of time are appropriate, but no time should be lost if there is true suspicion of a testicular tumor. Before the high inguinal exploration it is helpful to obtain serum levels of the beta subunit of human chorionic gonadotropin and alpha-fetoprotein, which are important tumor markers. Surgical exploration should not be delayed until the actual laboratory values are determined, as they are important to the longitudinal course of the patient and not necessarily to the diagnosis.

14. If torsion of the testicle is suspected, surgical exploration:
A. Can be delayed 24 hours and limited to the affected side.
B. Can be delayed but should include the asymptomatic side.
C. Should be immediate and limited to the affected side.
D. Should be immediate and include the asymptomatic side.
Answer: D

DISCUSSION: Torsion of the testicle should be corrected as soon as possible after the diagnosis is entertained. Incomplete torsion can cause partial strangulation, the effects of which may be overcome if surgical intervention is accomplished within 12 hours, whereas severe torsion with complete compromise of the blood supply results in loss of the testis unless surgical intervention occurs within approximately 4 hours. The contralateral scrotum should also be explored at the time of the operation, since the primary anatomic defect—insufficient attachment of the testicle to the scrotal sidewall—most often is a bilateral phenomenon. If the contralateral scrotum is not explored, the patient runs a very high risk of undergoing torsion on the other side and the possible complication of loss of both testes.

15. Epididymitis, either unilateral or bilateral, in a prepubertal male:
A. Is a frequent diagnosis.
B. Can be dealt with on an outpatient basis.
C. Is a major scrotal problem in this age group.
D. Is a rare phenomenon.
Answer: D

DISCUSSION: Epididymitis can occur in prepubescent males, but it is a rare phenomenon and usually occurs only in patients with chronic UTI, obstructed urethra, or very high voiding pressure. The diagnosis of epididymitis in the prepubertal male should be reviewed with suspicion because one of the more common causes of the clinical situation that presents as epididymitis is torsion of the testicle. If there is any concern about the validity of the diagnosis, the patient should undergo scrotal exploration. Epididymitis will not be compromised by surgical exploration, but delay in surgical exploration leads to loss of the testicle if the problem is torsion.

16. Patients with prostatitis, especially acute suppurative prostatitis:
A. Should have residual urine measured by intermittent catheterization.
B. Should have bladder decompression by urethral catheter.
C. Should have repeated prostatic massage.
D. Should have no transurethral instrumentation if possible.
Answer: D

DISCUSSION: Acute suppurative prostatitis should be treated with vigorous antibiotic therapy with broad-spectrum agents initiated immediately and changed in response to results of culture and sensitivity studies. Urethral instrumentation and repeated prostate examination should not be done, if at all possible, since sepsis is not unusual after either diagnostic examination or urethral catheterization. If the patient does need to have the bladder decompressed, it is beneficial to use a suprapubic catheter rather than a urethral catheter.

17. Benign prostatic hypertrophy with bladder neck obstruction:
A. Is always accompanied by significant symptoms.
B. Is best diagnosed by endoscopy and urodynamic studies.
C. Is easily diagnosed by the symptoms of frequency, hesitancy, and nocturia.
D. Is always accompanied by residual urine volume greater than 100 ml.
Answer: B

DISCUSSION: Benign prostatic hypertrophy with bladder neck obstruction is difficult, in some patients, to diagnose as they are totally asymptomatic, even if they have residual urines of greater than 1000 ml. or renal compromise consisting of the syndrome of so-called “silent prostatism.”

18. Which of the following statements are true concerning male infertility?

a. Although 15% of couples in the United States are affected by infertility, the male rarely contributes to the problem
b. A varicocele can be associated with diminished sperm motility and abnormal sperm morphology
c. Complete testicular failure will usually respond to systemic testosterone administration
d. Anti-sperm antibodies are an important cause of infertility which may be treated successfully with corticosteroid administration
Answer: b, d

Infertility is defined as the inability to conceive a pregnancy within one year of unprotected intercourse. About 15% of couples in the United States are affected, and in about 25%-50% of infertility cases, the male contributes to the problem. The cornerstone of male fertility evaluation is the semen analysis. Oligospermia, or a low sperm count, is an incomplete form of testicular failure due to a number of causes. A varicocele is found in about 15% of the general male population, but 40% of infertile men have this finding. Men with a varicocele can exhibit low sperm counts but more often have diminished sperm motility and abnormal morphology. Surgical ligation or angiographic embolization of the internal spermatic vein improves the semen parameters in 50%-70% of these men and gives subsequent pregnancy rates of 25%-50%. Complete testicular failure is diagnosed by a testis biopsy showing no sperm production or by a markedly elevated serum FSH level, indicating the absence of negative feedback inhibition induced by spermatogenesis. Complete testicular failure is not remedial by treatment. Anti-sperm antibodies are found frequently in infertile men and represent an important cause of infertility. Corticosteroid administration may be helpful if antibodies are present, but the toxicity of these medications cannot be ignored.

19. A 65-year-old male is diagnosed as having prostatic cancer based on transrectal biopsy of a 1 cm palpable nodule. Which of the following statement(s) are true concerning his management?

a. If the tumor is confined within the prostatic capsule (stage A or B), radical prostatectomy is an appropriate option
b. If positive lymph nodes are detected on laparoscopic pelvic lymph node dissection (stage Dl), radical prostatectomy is indicated
c. Radical prostatectomy is invariably associated with impotence
d. External beam radiation is an appropriate treatment if the tumor is confined to the prostate
e. There is currently no role for orchiectomy in the management of prostatic cancer
Answer: a, d

The treatment of prostatic cancer depends on whether the disease is localized to the prostate or advanced beyond the gland. Because prostate cancer advances slowly, the morbidity of therapy may exceed the therapeutic benefit in the elderly and debilitated. Patients who have a limited life expectancy and low stage disease are frequently treated with observation only. If the tumor is confined within the prostatic capsule (Stage A or B), options include radical prostatectomy, external beam radiation therapy, and radioactive implants. Radical prostatectomy is usually carried out through the retropubic approach. Through this approach a node dissection can be done for further staging, and the procedure abandoned if the nodes contain tumor. In patients with a high index of suspicion for positive nodes, a laparoscopic pelvic node dissection can be performed to decrease postoperative morbidity. The use of the nerve-sparing prostatectomy can be used to preserve penile erection in those patients who are potent. In this approach, the nerves concerned with penile erection are excluded from the dissection. The incidence of impotence following traditional radical prostatectomy is l00% but can be cut in half with the nerve-sparing approach. Hormonal ablation is the initial treatment of choice for advanced prostatic cancer. Most prostatic cancers are androgen-responsive. Androgen ablation will cause improvement in 80-90% of patients with regression of tumor in about 40%. The testis is the primary source of androgen and orchiectomy remains the gold standard and treatment of choice for advanced prostatic cancer. Estrogen will produce castrate levels of testosterone, but the side effects of fluid retention and increased incidence of thromboembolic diseases such as heart attacks and strokes make this hormone a poor choice in this high risk age group.

20. Extracorporeal shock wave lithotripsy (ESWL) has had a dramatic effect on the management of urinary stones. Which of the following statement(s) are true concerning shock wave lithotripsy of urinary stones?

a. The basic principle of lithotripsy involves the generation of shock waves which are focused fluoroscopically on the calculus and are delivered to the patient who is submersed in a water bath
b. The most common complication after lithotripsy is ureteral obstruction secondary to stone fragments
c. ESWL can be associated with stone-free rates ranging between 60%-95% at six months for renal and proximal ureteral stones
d. The combination of ESWL with percutaneous nephrolithotripsy improves the results for stone clearance in patients with large or branched stones such as staghorn calculi
Answer: a, b, c, d

The introduction of ESWL has virtually eliminated open surgery for renal and ureteral lithiasis. The basic principles of all lithotriptors include shock wave generation, focusing of the sound wave, and imaging of the stone. All lithotriptors produce shock waves by a spark gap electrode or by a piezoelectric or electromagnetic element. The wave is then focused towards the stone which is localized either employing fluoroscopy or ultrasonography. The patients are either submersed in a water bath or “coupled” by a water cushion. The acoustic density of water and body tissues is essentially the same. Therefore, there is little or no impedance of the shock wave at the water-body interface. Upon striking the stone, which is of different acoustical density, the shock wave undergoes reflection and refraction, resulting in compressive and tensile forces which fragment the stone.
Complications of ESWL are rare. The most common complication after ESWL is ureteral obstruction secondary to stone fragments requiring either additional ESWL, urethroscopic stone retrieval or stent placement. ESWL is the treatment choice for the vast majority of renal and proximal ureteral stones with stone-free rates ranging from 60%–95% at six months. Stones larger than 3 cm and branch stones such as staghorn calculi are best treated with percutaneous nephrolithotripsy alone or in combination with ESWL. The combination of extracorporeal and percutaneous techniques can result in average dome clearance rates in excess of 80%.

21. Which of the following statement(s) are true concerning bladder carcinoma?

a. Epidemiologic studies have implicated cigarette smoking as a risk factor
b. If cystoscopy demonstrates a bladder carcinoma as the cause of painless hematuria, no further evaluation is necessary
c. Multi-focal and recurrent bladder tumors are usually treated with transurethral resection and intravesical chemotherapy
d. The results of treatment for locally advanced bladder tumors are similar with either radical cystectomy or radiation therapy
Answer: a, c

A wealth of basic research and clinical data testify to a variety of chemical carcinogens inducing bladder cancer. Occupational exposure to beta-naphthylamine and para-aminophenyl results in an increased incidence of bladder cancer. Epidemiologic studies have also indicated cigarette smoke as a risk factor. Bladder cancer has a strong male prevalence and is almost three times more common in men than women. The hallmark of bladder cancer is painless, total gross hematuria. The usual diagnostic tests employed are excretory urography (IVP) and cystoscopy. The former is important because the upper tracts (renal pelvises and ureters) are also at risk for the development of urothelial neoplasia. Cystoscopy is not only diagnostic but also therapeutic because superficial tumors are easily excised or fulgurated through endoscopic instruments. Approximately 70% of patients with bladder cancer will present with local disease. This is associated with five year adjusted survival rate of 88%. Close vigilance is important because the recurrence rate exceeds 50%. Ten to 50% of superficial tumors will progress to invasive disease. Multifocal and recurrent tumors are usually treated with intravesical chemotherapy in addition to transurethral resection. Agents commonly employed include thiotepa, doxorubicin, and mitomycin C. Alternatively intravesical immunotherapy has been successfully performed with installation of BCG (Bacillus Calmette-Guerin). Locally advanced tumors are usually treated with radical cystectomy and urinary diversion. Radiation therapy has been employed but is associated with a high rate of local recurrence.

22. The most common malignant neoplasm of the kidney is the hypernephroma or renal cell carcinoma. Which of the following statement(s) are true concerning renal neoplasms?

a. Renal cell carcinomas can produce a variety of hormone or hormone-like substances
b. Bilateral multifocal renal cell cancers can be associated with the multiple endocrine neoplasia syndrome
c. A “tumor deformity” on IVP is diagnostic of a renal cell carcinoma
d. Early control of the renal pedicle is an important aspect of surgical management of renal cell carcinoma
e. Patients with renal cell carcinoma in a solitary kidney will inevitably require total nephrectomy and long-term dialysis for the resultant renal failure
Answer: a, d

Renal cell carcinoma or hypernephroma account for approximately 2% of all cancers diagnosed annually. It is most common after the fifth decade of life and has a male to female ratio of approximately 2:1. No definite etiology has been identified, but a frequent genetic abnormality detected in renal cell cancer is the loss of heterozygosity of chromosome 3p. Multifocal bilateral tumors are associated with von Hippel-Lindau disease. Renal carcinomas can produce a variety of hormone or hormone-like substances (e.g., erythropoietin, renin, and parathormone) and may present with a variety of symptoms including anemia, hypertension, fever and erythrocytosis. Excretory uroraphy (IVP) provides a good renal image with superior detail of the collecting system. Renal masses such as benign cysts or renal cell carcinomas will both appear as “tumor deformities”, distorting the renal outline or the collecting system. Renal cysts are far more common than renal cell carcinoma and the diagnosis can be confirmed by renal ultrasound. Surgical excision remains the primary mode of treatment for renal cell carcinoma. Although the need for radical nephrectomy has recently been questioned, this procedure remains a gold standard against which less radical procedures must be judged. Radical nephrectomy is performed through an abdominal or a thoracoabdominal approach and involves early control of the renal artery and vein. The tumor, together with the kidney and the perirenal fat is excised within Gerota’s fascia which is not opened. Less radical approaches have been suggested for the treatment of smaller tumors, including partial nephrectomy. This approach is especially valuable for bilateral tumors or in patients with a solitary kidney or poor overall renal function.

23. A 28-year-old white male presents with asymptomatic testicular enlargement. Which of the following statement(s) is/are true concerning his diagnosis and management?

a. Tumor markers, b-fetoprotein (AFP) and ك-human chorionic gonadotropin (HCG) will both be of value in the patient regardless of his ultimate tissue type
b. Orchiectomy should be performed via scrotal approach
c. The diagnosis of seminoma should be followed by postoperative radiation therapy
d. With current adjuvant chemotherapy regimens, retroperitoneal lymphadenectomy is no longer indicated for non-seminomatous testicular tumors
Answer: c

Testis cancer is most common between the ages of 25 and 34 and is rare in blacks. The most common malignant neoplasm of the testis arise from the germ cells and can represent a variety of histologic manifestations, e.g, choriocarcinoma, embryonal cell carcinoma, seminoma, and teratoma. For therapeutic purposes, the tumors can be divided into seminomas and nonseminomas. The usual presenting symptom is testicular enlargement that may be associated with mild discomfort. Any solid testicular mass should be considered suspicious for testis carcinoma. The diagnostic and therapeutic approach for any suspected testis carcinoma is inguinal exploration with orchiectomy if the operative findings confirm the presence of a testicular mass. The inguinal approach is employed to perform high ligation of the cord at the inguinal ring and to eliminate potential involvement of the inguinal lymph nodes which are the primary area of drainage for the scrotum. The tumor markers, a-fetoprotein (AFP) and the b-human chorionic gonadotropin (HCG) can contribute to both diagnosis and follow-up of testis cancer. Tumor markers are helpful when obtained prior to and following orchiectomy to help in assessing the stage of the tumor. Pure seminoma does not cause elevated AFP but can produce a moderate rise in HCG in 10% of patients. Seminomas are very responsive to radiation. Patients with minimal to moderate tumor burden (Stage I or II) are usually treated with radiotherapy. The field of treatment encompasses the para-aortic and para-caval areas below the diaphragm and ipsilateral inguinal and pelvic areas. When bulky retroperitoneal and/or distant metastases are present, cisplatin-based combination chemotherapy is the preferred treatment. The treatment of non-seminomatous tumors is more controversial. Stage I tumors are effectively treated with retroperitoneal lymphadenectomy. If bulky stage II and stage III non-seminomatous tumors are present, initial treatment includes cisplatin-based chemotherapy. Evidence for residual disease with normalization of tumor markers is usually an indication for surgical exploration.

24. Which of the following statement(s) is/are true concerning benign prostatic hypertrophy (BPH)?

a. Prostatic size has no consistent relationship to urethral obstruction
b. Renal failure secondary to obstructive uropathy occurs as bladder pressure rises and is eventually transmitted proximally to the renal pelvis
c. Hormonal treatment for BPH involves treatment with a 5 a-reductase inhibitor which blocks the conversion of testosterone to the dihydrotestosterone
d. Intermittent catheterization, although a temporizing measure, is not an effective treatment for relief of symptoms of BPH
Answer: a, b, c

The prototypic bladder outlet obstruction is prostatic hyperplasia, which urologists once visualized as a progressive encroachment on the urethral lumen related to prostatic growth. It is now clear that prostatic size has no consistent relationship to obstruction and the diagnosis of obstructive uropathy cannot be made by endoscopic inspection or by determination of prostatic size or appearance. Obstruction results in progressive increases in bladder pressure and decreased urine flow rates. If bladder pressures are high enough and sustained long enough, the ureteral pump mechanism is overcome, the ureter dilates, and by a hydraulic mechanism, intervesicular pressure is transmitted to the renal pelvis. At a pressure of 42–50 cm H2O, glomerular filtration ceases. These relatively simple sequential events lead to renal failure. Prostatic enlargement clearly has an endocrine basis since treatment with a 5 a-reductase inhibitor, which blocks conversion of testosterone to dihydrotestosterone (the active male hormone in the prostate) can induce a 30% to 50% regression in prostatic size. Although surgery or hormone therapy may be effective in initiating reversal of changes associated with obstructive uropathy, this does not occur invariably. Removal of the hyperplastic glandular tissue is the most effective treatment in terms of relief of symptoms. Patients who cannot be subjected to operation, however, show the same response to intermittent catheterization and periodic bladder emptying in terms of symptoms as well as bladder wall and pressure changes.

25. A 55-year-old male presents with severe flank pain radiating to the groin associated with nausea and vomiting. Urinalysis reveals hematuria. A plain abdominal film reveals a radiopaque 5 mm stone in the area of the ureterovesical junction. Which of the following statement(s) is/are true concerning this patient’s diagnosis and management?

a. A likely stone composition for this patient would be uric acid
b. The stone will likely pass spontaneously with the aid of increased hydration
c. Stone analysis is of relatively little importance
d. Patients with a calcium oxalate stone and a normal serum calcium level should undergo further extensive metabolic evaluation
Answer: b

It is estimated that 12% of the U.S. population will develop calculus disease during their lifetime. Males have more than twice the rate of stone formation than females. Caucasians have between a two to tenfold higher incidence of renal stone disease than Blacks or Asians. The peak incidence of lithiasis appears to be between the ages of 45 and 64 years. Almost 3/4 of stones are composed of calcium oxalate in combination with calcium phosphate. Magnesium ammonium phosphate (struvite) or infection stones make up approximately 12% whereas pure calcium phosphate and uric acid stones each compromise 7%. The diagnosis of renal stones is made with appropriate history and performance of urinalysis and a non-contrast abdominal radiograph. Urinalysis of a patient with a urinary stone will have evidence of either gross or microscopic hematuria in 85%-95% of patients. Eighty-five to 90% of urinary stones are radio-opaque. Uric acid stones are typically not radio-opaque.
The majority of stones will pass spontaneously with aid of increased hydration and appropriate analgesics. All stones passed should be retrieved for subsequent analysis. Patients passing their first stone should have serum calcium and creatinine levels and a urinalysis in addition to stone analysis. If the stone is calcium oxalate and the serum calcium level is normal, no further evaluation is necessary other than encouraging the patient to increase fluid intake. Any patient with stones composed of uric acid, pure calcium phosphate, cystine, or struvite are at high risk for continued stone formation and should undergo more extensive metabolic evaluation. In addition, those patients with recurrent or enlarging stones, including those patients with known calcium oxalate stones, should undergo a metabolic evaluation.

26. Which of the following statements are true concerning male impotence?

a. Psychologic factors account for less than half the cases of male impotence
b. Vascular testing for vasculogenic impotence may include Doppler determination of penile systolic blood pressure and super selective pelvic arteriography
c. Penile implants are the first line treatment for patients with impotence due to diabetes or vascular dysfunction
d. Impotence associated with abdominal perineal resection is due to direct trauma to pelvic nerves and may be improved with papaverine injection
Answer: a, b, d

Erectile dysfunction is a common condition that affects 10 million American men. The incidence increases with age. By age 55 about 8% of men are affected. By the age of 80 years, the incidence is 75%. Impotence ensues from interference with the normal vascular, neurologic, psychological, endothelial, and hormonal mediators of erection. In many cases, the causes are multi-factorial. Psychological factors can inhibit as well as stimulate erection and account for less than half of the cases of impotence. Although a number of systemic diseases can cause impotence, diabetes is the most common. Impotence may also result from systemic neurologic diseases such as multiple sclerosis. Direct trauma to the pelvic nerves by pelvic fractures of radical pelvic surgery (radical prostatectomy, abdominal perineal resection) may also be associated with impotence.
The determination of the effect of vascular disease on impotence can be determined through a number of techniques. An estimate of penile blood flow can be made through Doppler determination of penile systolic blood pressure using a penile cuff. Direct corporal injection with papaverine, a smooth muscle relaxant, bypasses psychogenic and neurologic factors and produces an erection if the blood flow to the penis is normal. If arterial disease is suspected on the basis of poor response, superselective pelvic arteriography with injection of vasoactive agents is necessary to document the nature of the disease.
The treatment of impotence depends on both the cause and the patient’s willingness to pursue various therapeutic approaches. Patients with neurogenic impotence, such as following pelvic nerve injury, can experience dramatic results with papaverine injection. Penile implants can be used to treat any type of intractable impotence, but they are usually reserved for patients with diabetes or vascular neurologic dysfunction who do not respond to conservative measures.

27. Which of the following statement(s) are true concerning the detection and diagnosis of prostatic cancer?

a. An elevation of prostate specific antigen (PSA) is highly sensitive and specific for prostatic carcinoma
b. American blacks have an increased risk of prostatic carcinoma
c. Autopsy series would suggest that 10% of men in their 50’s will have small latent prostatic cancers
d. Transrectal prostatic biopsy is indicated for a palpable 1 cm prostate nodule
e. Serum prostatic acid phosphatase remains the most useful tumor marker for prostatic carcinoma
Answer: b, c, d

Adenocarcinoma of the prostate is the most common non-cutaneous malignant tumor in men, accounting for 20% of all male cancers and is the second highest cause of cancer deaths in males. It is primarily a disease of older men. At autopsy, about 10% of men in their 50’s can be shown to have small latent tumors, and with this number increasing to 70% of men in their 80’s. However, it is estimated that only 10% of men over 65 will develop clinically significant prostate cancer. An increased incidence in American blacks has been reported.
Early prostate cancer has few symptoms. Therefore, early diagnosis requires detection of small tumors within the prostate gland. Three modalities are used in the early detection of prostate cancer. These include digital rectal examination, serum prostate specific antigen (PSA), and transrectal ultrasound of the prostate. Prostate tumors usually arise in the posterior lobe of the prostate an area readily palpable on digital rectal examination. Early prostatic cancer frequently presents as a small firm nodule within or at the periphery of the gland. If a 1 cm nodule is detected, it is cancer about 50% of the time. Prostatic biopsy is readily performed with little morbidity and is often required to confirm the diagnosis. Transrectal ultrasound of the prostate may also detect prostate cancer often as a smaller more subtle lesion not easily discernable on rectal examination. However, digital examination will also disclose some cancers that are not visualized with ultrasound. Serum PSA is used to aid in the early detection of prostate cancer. PSA is elevated in 68% of men with cancer but 33% of men with benign enlargement of the gland also have an enlarged PSA. Serum prostatic acid phosphatase is not specific for prostatic cancer although a significant elevation is usually associated with metastatic disease. Serum acid phosphatase however has been generally replaced as a tumor marker by the immunoassay for PSA. PSA is also an extremely sensitive tumor marker for recurrences after surgery because serum levels should be undetectable if patients are tumor-free.