Chest Wall, Pleura and Mediastinum (TCVS) Flashcards

Question

Excisional biopsy of a chest wall mass is allowed if A. Needle biopsy was nondiagnostic. B. Imaging reveals classic appearance of a chondrosarcoma. C. It is >3cm. D. None of the above.

Answer 1

Answer: B 1. Needle biopsy: Pathologists experienced with sarcomas can accurately diagnose approximately 90% o patients using FNA cytology. A needle biopsy (FNA or core) has the advantage of avoiding wound and body cavity contamination (a potential complication with an incisional biopsy). 2. Incisional biopsy: If a needle biopsy is nondiagnostic, an incisional biopsy may be performed, with caveats. First, the skin incision must be placed directly over the mass and oriented to allow subsequent scar excision; skin laps and drains should be avoided. However, if the surgeon believes a hematoma is likely to develop, a drain is useful for limiting soft tissue contamination by tumor cells. At the time of definitive surgical resection, the en bloc resection includes the biopsy scar and the drain tract along with the tumor. 3. Excisional biopsy: Any lesion less than 2.0 cm can be excised as long as the resulting wound is small enough to close primarily. Otherwise, excisional biopsy is performed only when the initial diagnosis (based on radiographic evaluation) indicates that the lesion is benign or when the lesion has the classic appearance of a chondrosarcoma (in which case, definitive surgical resection can be under- taken). (See Schwartz 10th ed., p. 666.)

Answer 2

A. PET scanning uses fluorodeoxyglucose (FDG) with radiolabeled fluorine to help detect malignant cells. Malignant cells metabolize glucose at a higher rate than normal cells, resulting in a radiolabeled metabolite of FDG, which results in a visual marker to help identify malignant cells, nodal stage, and metastases. Surgical resection without any attempt at preoperative staging is not appropriate. Although cervical mediastinoscopy may be an important step in assessing the stage of thÿs patients lung cancer, PET scanning may identify suspicious nodes and distant metastasis and helps guide the surgeon on where to obtain the appropriate tissue for diagnosis.

Answer 3

B. Surgery is contraindicated for Stage IIIB and IV lung cancer. T4 lesions are classified as stage IIIB if they are associated with N2 disease. Tumors of any size are T4 if they invade the heart, great vessels, trachea, esophagus, vertebral body, or carina. Tumors associated with malignant pleural or pericardial effusions are considered to have MIA disease, which precludes surgical intervention. T3 tumors include tumors of any size that directly invade any of the following: diaphragm, chest wall, mediastinal pleura, parietal pericardium, or a tumor invading the main bronchus less than 2 cm from the carina (without involvement of the carina). Depending on nodal and metastatic involvement, T3 tumors may not result in a staging level of IIIB or IV. Thus, surgery may be appropriate in select patients presenting with T3 tumors. Preoperative testing of pulmonary functional reserve is essential prior to determining whether a patient is a candidate for surgical resection. In gen¬ eral, a predicted post-operative FEVj less than 40% is thought to be a contraindication to surgical resection. Although a post-operative predicted FEV1 of 45% is not an absolute contraindication to surgical resection, it certainly merits thorough preoperative patient assessment (including evaluation of comorbidities, and predicted lung diffusion capacity). It is also important to remember that if the lung to be resected is not actually functional (secondary to collapse or bronchial obstruction) than the post-operative predicted FEV, should not be expected to change significantly from the preoperative FEV1. Conversely, if the lung to be resected happens to be functional, but the patient has other areas of lung that are non-functional, than the FEV1 will actually decrease more dramatically when this functional lung is resected.

Answer 4

C. Structures that would be need to be divided for a right upper lobectomy from anterior to posterior are the superior pulmonary vein, truncus anterior, and upper lobe bronchus. This is a simplified description of the most commonly encountered anatomy for the main structures seen. During dissection the surgeon must be mindful of aberrant anatomy (often noted on preoperative imaging) and more commonly branching vessels, which may appear in different planes than listed above.

Answer 5

E. NSCLC is most likely to relapse within the first two years after resection (over 60%). Thus, oncologic surveillance should be done every 3 to 4 months during this time. Though there is no single recommendation for surveillance beyond 2 years, coordinated oncologic surveillance should be performed long-term. Though relapse of NSCLC is common in the bone, the most common site of relapse for all stages of NSCLC is the brain. Other sites of relapse include the lung (ipsilateral or contralateral), liver, and adrenal glands. There is no indication for radiation therapy post-operatively.

Answer 6

E. Paraneoplastic syndromes develop in as many as 40% of patients with newly diagnosed lung cancers. Significant hyponatremia in the setting of a newly diagnosed lung mass is highly suspicious of syndrome of inappropriate antidiuretic hormone (SIADH). It is important to recognize that SIADH is most commonly associated with small cell lung cancer (SCLC). In addition to hyponatremia, the diagnosis of SIADH is confirmed by demonstrating a serum osmolarity <275mOsm/kg, urine osmolarity > serum osmolarity, and urine sodium > 25 meq/L. Associated symptoms may include lethargy, nausea, vomiting, altered mental status, and seizures. SCLC account for D20% of all lung cancers. These tumors are known for rapid growth, and thus often present with necrosis. They commonly invade vascular and lymphatic tissue, and metastasize early. Up to 70% of patients present with metastasis at the time of diagnosis. Given that SCLC is a systemic disease, chemotherapy is the primary medical treatment. Combination chemotherapy with the addition of radiotherapy for locorégional control has been shown to improve survival. Additional prophylactic cranial irradiation has been shown to decrease the incidence brain metastasis, but has not been shown to improve overall survival. Other paraneoplastic syndromes associated with hormone alterations should also be recognized. Often Patients with SCLC may exhibit elevations in adrenocorticotropic hormone (ACTH). This may manifest with hypokalemia, hyperglycemia, and metabolic alkalosis. Diagnosis can be confirmed by measuring elevated ACTH in the blood or elevated 17-hydroxycorticosteroid levels in the urine.

Answer 7

1. (A) Ostium primum. Typically ostium primum in an adolescent would be diagnosed by increasing symptoms, increased pulmonary resistance, left axis on ECG, and a mitral regurgitation murmur due to a cleft mitral valve. Ostium secundum would cause increased pulmonary resistance later in life, not at age 14. AV canal is seen most commonly in Down syndrome. Right aortic arch and tetralogy of Fallot do not have this symptom complex.

Answer 8

2. (E) Prostaglandin E1 and Aterial septotomy. Prostaglandin E1 is used to keep the ductus arteriousus open in transposition. Desaturated “systemic” blood can pass through the pulmonary circulation to be oxygenated. The aterial septotomy creates an ASD, which aids in saturated blood being pumped peripherally, decreasing the cyanosis. The mustard operation is not commonly done as the arterial switch operation is most common in this era, and in this acutely ill neonate definitive operation would not be the best initial treatment. Pulmonary artery banding does not apply.

Answer 9

3. (C) Internal thoracic artery. The internal thoracic artery is the conduit of choice especially for grafting the left anterior descending (LAD) artery. Arterial and venous grafts 95% of the time do not occlude after 12. Seventy-five percent of patients under coronary artery bypass graft (CABG) survive 5 years. Mortality is 2% or lower in most centers.

Answer 10

4. (D) Echocardiography. This patient has a pericardial effusion. Echocardiography is the most useful in making the diagnosis. CAT scan of the chest can be used but is not the best exam. The other choices do not apply.

Answer 11

5. (E) Pericardial window. The patient developed decreased cardiac output (decreasing urine output,)and cardiac tamponade. Emergent pericardial window is the treatment of choice. Medical therapy will result in the patient’s death. The other choices do not apply.

Answer 12

6. (A) IABP increases coronary perfusion during distole. The IABP inflates during diastole and propels blood into the coronary circulation. IABP decreases peripheral resistance and decreases afterload on the heart. The IABP can stay in the patient for longer than 24 hours.

Answer 13

7. (D) ICD. In a patient with history of MI, congestive heart failure, and decreased ejection fraction coupled with frequent premature ventricular beats studies have shown that this subset of patient benefits from internal cardiac defibrillators, as the most frequent cause of death in these patients is sudden cardiac death from ventricular fibrillation. Single and dual chamber pacemakers are used for bradyarrythmias. The other choices do not apply.

Answer 14

8. (B) Increase in pulmonary vascular resistance causes an increased cardiac output. Small shunts (with a pulmonary/systemic flow ratio >1.5) do not require surgery but must be treated with prophylactic antibiotics. Larger shunts should be repaired, because the mortality rate exceeds 50% when severe pulmonary pressure (>85 mm Hg) occurs. Closure of the VSD in the presence of cyanosis with established reversal of the direction of flow (right to left) would be detrimental, carrying a very high mortality.

Answer 15

9. (B) VSD is the most common cardiac congenital abnormality and results from failure of fusion of the uppermost part of the interventricular septum with the aortic septum. Membranous septal defects account for 90% of VSDs. There is usually a left-to-right shunt and cyanosis does not occur until pulmonary hypertension is severe enough to reverse flow across the VSD. Surgery is indicated in large shunts only when symptoms occur and pulmonary hypertension is evident. Forty percent will close spontaneously in childhood.

Answer 16

10. (D) Increase in pulmonary resistance would require more urgent intervention. Because nearly half the cases of VSD in childhood will close spontaneously, elective surgery is deferred to late childhood. Banding procedures are used less frequently today because of the high mortality rate. If symptoms increase in severity and pulmonary pressure is high, more urgent intervention is indicated. If the pulmonary systolic pressure is over 85 mm Hg and the left-to-right shunt is small, surgical mortality exceeds 50%.

Answer 17

11. (B) Management of compromised respiratory status in the premature infant with PDA includes fluid restriction, adequate oxygenation, attempted closure by medication with indomethacin, and surgical ligation (undertaken when indomethacin is contraindicated). Good results can be anticipated in the absence of other serious complications.

Answer 18

12. (A) In full-term infants born with persistent PDA, the anomaly must be closed or excised between 6 months and 3 years of age to avoid cardiac complications, including endocarditis. In PDA, persistence of the communication between the pulmonary trunk and aorta increases pulmonary blood flow, left atrial flow, left ventricular flow, and ascending aorta flow. PDA accounts for 15% of all congenital cardiac abnormalities. Cyanosis does not occur initially, because oxygenated blood is shunted from the aorta to the pulmonary trunk. The murmur is continuous (sounds like machinery) and has harsh features. Its intensity is maximum over the left second intercostal space but radiates to the chest wall and the neck.

Answer 19

13. (E) Cardiac catheterization is the definitive test for confirming the diagnosis of ASD. It quantifies the size of the shunt and confirms the increase in oxygen saturation between the right ventricle and the superior vena cava. Beading of the ribs is seen in coarctation, and a decreased carotid pulse is found in aortic stenosis. An elevated sedimentation rate occurs in the presence of infection such as bacterial endocarditis.

Answer 20

14. (E) There is decreased vascularity of the lungs seen on chest x-ray. Tetralogy of Fallot includes VSD, right ventricular outflow obstruction, dextroposition of the aorta, and right ventricular hypertrophy. Tetralogy of Fallot accounts for over one-half the cases of congenital cyanotic heart disease.

Answer 21

15. (B) Dilation of the left atrium is the obvious complication following long-standing mitral stenosis. Echocardiography is the simplest and most precise method of showing enlargement of the left atrium. Frequently, there is a latency period of 15–20 years before symptoms become evident. Important complications of mitral stenosis include exertional dyspnea caused by an increase in left atrial pressure and backup of blood with possible pulmonary edema, decreased cardiac output, atrial fibrillation, emboli (15%), and pressure in the intermediate third of the esophagus as seen on an esophogram after barium swallow. The pulse in mitral or aortic stenosis is reduced.

Answer 22

16. (D) Elevation of total cholesterol/high-density lipoprotein is a useful predictor of coronary artery disease (CAD). Other known main risk factors include genetic predisposition, high cholesterol level, arterial hypertension, and cigarette smoking. Obesity, diabetes mellitus, and personality type are of probable importance as independent risk factors. The presence of elevated high-density lipoprotein is a favorable factor.

Answer 23

17. (C) Changes in the nature of angina should alert the physician to the possible progression of the underlying cardiac status. The pain may become more severe and more frequent, may last longer, and may occur with a lesser degree of exertion. Nocturnal pain should likewise signal concern. In the face of unstable angina, 30% of patients are likely to develop MI within a 3-month period.

Answer 24

18. (C) In about one-quarter of patients with angina pectoris, the ECG findings will be normal. Exercise electrocardiography will reveal STsegment depression and possibly precipitate symptoms if angina pectoris is present. There is a risk of myocardial death in patients tested, and patients with symptoms after minimal exertion and/or unstable angina are at particular risk with this procedure. If hypotension, ventricular arrhythmia, and supraventricular arrhythmia occur or if the ECG shows a fall in segment ST of over 3 mm, the test should be discontinued. In these cases, 201Tl scintigraphy would be used to detect cardiac ischemia or infarction. Echocardiography during supine exercise may be a helpful test in selected circumstances.

Answer 25

19. (C) 99mTc pyrophosphate scintigraphy showing a “hot spot.” Following injection of 99mTc pyrophosphate, scintigraphy may show a hot spot in the infarcted area. The hot spot is developed as the radiotracer forms a complex with calcium in necrotic tissue. The test should be requested within the first 18 hours following the onset of acute MI. It is not sensitive enough to detect small infarctions. Following 201Tl scintigraphy, a “cold spot” occurs because of hypoperfusion. The test is performed where exercise or dipyridamole (Persantine) injection can be given. SGOT levels are elevated in liver disease. The HIDA scan is used to exclude gallbladder disease. Cardiac enzyme levels and ECG findings are useful to establish a diagnosis of MI.

Answer 26

20. (A) Thrombolytic therapy intravenously with streptokinase, urokinase, or tPA is indicated in most patients with MI presenting early for treatment. This therapy, however, is effective only if initiated within 6 hours after the onset of pain in patients with acute MI. These drugs are fibrinogenolytic, and aspirin and heparin are frequently included in the anticoagulant protocol. Reperfusion rates of 60% can be anticipated; reocclusion rates of 15% usually occur. Vitamin K is not indicated, because it would increase the coagulability of blood. If a diuretic, such as hydrochlorothiazide, 25–50 mg/d is indicated to treat milder hypertension, hypokalemia must be avoided.

Answer 27

21. (D) Studies have shown that in men over the age of 50, taking 1 tablet of aspirin (325 mg) on alternate days reduces the incidence of subsequent CAD complications. Nitroglycerin is prescribed if angina pectoris develops, and digoxin would be indicated if congestive heart faliure (CHF) is evident. Progression of atherosclerosis should be minimized by appropriate diet and exercise. The intake of excess of cholesterol and saturated fats in the diet causes changes in the vascular endothelium and smooth muscle proliferation, with subintimal fat and fibrous tissue accumulation leading to occlusion of the coronary arteries, their branches, and other arteries.

Answer 28

22. (B) Sudden cardiac death is defined as an unexpected death occurring within 1 hour after the beginning of symptoms in a patient who was previously hemodynamically stable. In asymptomatic patients presenting initially with cardiac disease, 20% will die within the first hour of symptoms. Electrolyte imbalance, hypoxia, and conduction system defect are additional factors that increase the risk of sudden death syndrome. Split first heart sound accentuated on inspiration occurs in normal individuals. In CHF, the CVP changes more than 1 cm when pressure is applied below the right costal margin to the liver (hepatojugular reflex) for a 30-second period. New York Classification of Functional Changes in Heart Disease Class Limitation of Physical Activity I None II Slight III Marked IV Complete (even at rest)

Answer 29

23. (C) The patient described has cardiogenic shock due to postoperative MI. The mortality rate for patients who develop MI is increased to more than 60% if hypotensive cardiogenic shock also supervenes. Pathology studies of patients dying after such episodes reveal that more than 40% of the heart will have infarcted. Inotropic drugs such as dobutamine are used. If a rapid response is not obtained, intra-aortic balloon tamponade is provided to unload the left ventricle during systole and increase diastolic coronary arterial flow. Hypertonic solutions in graded amounts would be given only if hypovolemia is evident. Atropine and adrenaline would be contraindicated.

Answer 30

24. (D) The balloon usually is inserted via the femoral artery. The balloon is inflated during diastole and deflated during systole. It is important that the balloon be adequately deflated during systole to avoid damage to the left ventricle. The pump can be used for a few days if required.

Answer 31

25. (D) The major complications occurring in atrial fibrillation are cardiac failure, coronary ischemia, and emboli. Emboli may lead to stroke. Urgent cardioversion is required in patients with auricular fibrillation if heart failure, hypotension, or angina are also present. Immediate cardioversion is indicated in ventricular tachycardia or ventricular fibrillation. If treatment with lidocaine is ineffective, electrocardioversion with 100–200 J for ventricular tachycardia or 300–400 J for ventricular fibrillation is urgently indicated.

Answer 32

26. (A)Alternate pressure over the carotid sinus for 20 seconds will end an attack of paroxysmal tachycardia in nearly one-half of cases. The procedure is contraindicated in patients who have had a cerebral TIA or those who have a carotid bruit. Bilateral simultaneous pressure on the carotid sinus carries an additional risk of stroke and must be avoided. The common carotid artery usually divides at the level of the upper border of the thyroid cartilage or hyoid bone (C3). The carotid sinus may be located either on the proximal internal carotid artery or distal common carotid bifurcation. Eyeball pressure may be effective but carries the risk of retina detachment. If initial measures are unsuccessful, the arrhythmia is treated with intravenous administration of verapamil or a similar drug. Electrocardioversion is indicated in severe cases, particularly if there are adverse symptoms caused by the tachycardia.

Answer 33

27. (A) Myxomas constitute more than 50% of all primary cardiac tumors. They are usually polypoid and attached to the septum. Sarcomas constitute 20–25% of primary cardiac tumors. Cardiac metastases are seen in patients with metastatic disease.

Answer 34

28. (C) The pulse is bounding when the pulse pressure is magnified because of a wide difference between the systolic and diastolic pressure. It may be due to aortic incompetence, PDA, or noncardiac causes that result in increase in cardiac output and decreased peripheral resistance (e.g., hyperthyroidism, peripheral AV fistula, or anemia).

Answer 35

29. (A) A small pulse occurs when the cardiac output is decreased and/or the peripheral resistance is increased. The pulse is reduced in aortic stenosis, heart failure, pulmonary hypertension, pulmonary incompetence, mitral stenosis, and pericardial effusion. The typical cardiac lesion in syphilis is aortic incompetence, which results in a forceful bounding pulse with a wide pulse pressure. Other noncardiac conditions that result in an increased pulse pressure include hyperthyroidism, carcinoid syndrome, and aortic incompetence.

Answer 36

30. (B) Angioplasty and stenting of the iliac vessels has a patency rate of 75% at 5 years; PTA and stenting of all other vessels has a much lower patency than bypass procedures. The FDA has only approved illiac artery stenting.

Answer 37

31. (D) The single most serious prognostic sign for adverse changes after vascular surgery is the presence of CHF. Every effort must be made to correct pulmonary congestion and improve left ventricular function before undertaking elective procedures. MI occurring within 3 months before operation carries a high mortality rate that will be reduced by delaying surgery for 3–6 months when possible.

Answer 38

32. (B) Cerebrovascular accident is the most important cause of death during the first year of life in patients with tetralogy of Fallot. Over 65% of patients with the tetralogy have cyanosis before 1 year of age. These patients have more severe polycythemia and are particularly liable to develop cyanotic spells of unconsciousness, cerebral thrombosis, hemiplegia, and death. Brain abscess may develop subsequent to infarction and bacteria’s entering the systemic circulation via a right-to-left shunt.

Answer 39

33. (A) A double aortic arch implies that there are two arches of the aorta; one passes posterior to the esophagus and the other anterior to the trachea. The right side is more common than the left side, and usually one of the arches is smaller than the other. Respiratory difficulty with a labored type of respiration (often precipitated by feeding) usually occurs within the first few months of life. Dysphagia occurs less frequently. Treatment is required only if symptoms are troublesome.

Answer 40

34. (D) Coarctation of the aorta is a relatively common anomaly and accounts for approximately 15% of all congenital anomalies. The most common site of coarctation is immediately distal (within 3–4 cm) to the origin of the left subclavian artery. Normally, pressure in the lower extremity is higher than that in the upper extremity, but in coarctation of the aorta, the femoral pulses are absent or markedly reduced. Magnetic resonance imaging (MRI) (cine) of chest shows coarctation (Fig. 4–2).

Answer 41

35. (C) In the fetus, the sixth left aortic arch diverts blood in the pulmonary artery away from the undeveloped lungs. After birth, the channel closes and becomes the ligamentum arteriosum. In rubella, a PDA may be associated with mental retardation and cataracts. Most cases of PDA occur without a clear-cut cause.

Answer 42

36. (D) In the presence of coarctation of the aorta, left ventricular enlargement, hypertrophy, and failure to develop occur. As the child grows, collaterals develop between the subclavian artery and the aorta via the intercostal and internal thoracic vessels. In children older than 8 years of age, the intercostal arteries cause typical notching on the inferior margin of the ribs.

Answer 43

37. (E) Tricuspid atresia accounts for 5% of cyanotic heart disease. Blood to the lungs is maintained by a PDA.

Answer 44

38. (H) Repeat blood pressure assessment in the supine position. Hypertension can be defined as a diastolic pressure above 90 mm Hg or systolic pressure above 160 mm Hg. Anxiety in an office setting may provide a false high reading of blood pressure. The pressure usually decreases when the individual remains seated and still for a short while. Essential hypertension implies that there is no clear associated cause to explain the hypertension. Approximately 10–15% of white adults and 20–30% of black adults in the United States suffer from hypertension.

Answer 45

39. (D) Diuretics and angiotensinogen-converting enzyme (ACE) inhibitors are more likely to be effective in elderly black men presenting with hypertension. ACE inhibitors inhibit the renin–angiotensin–aldosterone system, sympathetic nervous system activity, and bradykinin degradation and cause an increase in prostaglandin (vasodilator) synthesis. PBlockers (e.g., propanalol) and calcium channel blockers (e.g., verapamil, nifedipine) are the first line of drugs chosen for young white men presenting with hypertension.

Answer 46

40. (B) The presence of mild stenosis (valve gradient/right ventricular pulmonary artery <30 mm Hg) in asymptomatic patients does not require surgical correction; such patients can anticipate a normal life expectancy. Moderate to severe stenosis (right ventricular/pulmonary artery gradient of 50–80 mm Hg) requires surgical correction.

Answer 47

41. (G, I) Percutaneous balloon valvuloplasty is now used in many centers as an initial approach to correct pulmonary stenosis. Right ventricular hypertrophy accounts for the parasternal heave noted on examination. Left ventricular hypertrophy does not occur consequent to pulmonary stenosis. Pulmonary stenosis was once considered rare but now accounts for 10% of cases of congenital heart disease.

Answer 48

42. (E) Sodium nitroprusside, 0.5–10 mg/kg/min IV, is given to patients (such as the one here) presenting as an urgent hypertensive emergency (e.g., symptomatic hypertension with systolic blood pressure >200 mm Hg, or asymptomatic with systolic pressure >240 mm Hg). Sodium nitroprusside lowers blood pressure by causing arteriolar and venous dilation. Untreated hypertension may lead to cardiovascular, cerebrovascular, and renal disease. Other complications of hypertension include pulmonary edema, aortic dissection, progressive atherosclerosis, accelerated (malignant) hypertension, and, in pregnant patients, eclampsia.

Answer 49

43. (D) Next move should be sampling of mediatinal nodes to stage this carcinoma of the lung. If the nodes are positive, the patient is not a surgical candidate. He needs chemo-radiotherapy. Radiation to the mediastinal nodes should not begin without pathologic confirmation of nodal metastasis. Waiting constitutes malpractice.

Answer 50

44. (D) This patient has probably suffered a penetrating injury to the vessels of the thoracic outlet and/or superior mediastinum. Immediate operation is needed. This incision gives excellent exposure on the right and also gives access to both chest cavities.

Answer 51

45. (D) Positive ipsilateral parathracheal nodes | defines stage IIIA.

Answer 52

46. (D) In the past, prolonged intubation (internal fixation) was performed with enthusiasm because the pulmonary failure was thought to be secondary to chest wall instability. Today is known that pulmonary failure and breathing problems are due to lung contusion and pain, respectively. Avoiding intubation, controlling pain, and performing aggressive bronchial toilette yield better results.

Answer 53

47. (D) During the early period of the fibrinopurulent stage of empyema, thoracoscopy is the standard of care.

Answer 54

48. (C)Adenocarcinoma, originated from islands of Barrett’s esophagus, is today the most common cancer of the esophagus in the United States.

Answer 55

49. (D) Today, the standard of care for classic achalasia is laparoscopic myotomy and partial fundoplication.

Answer 56

50. (C) Perforation of the esophagus is associated with serious complications and death. Earliest repair is mandatory. Antibiotics would also be given. The other choices allow an on-going leak.

Answer 57

51. (E) The esophagus is not perforated because of the patient’s dramatic improvement. Achalasia is usually accompanied by chronic dysphagia. Short esophagus does not present with severe retrosternal pain. The nasogastric tube is looped inside the intrathoracic, volvulated stomach and the patient has improved because of decompression.

Answer 58

52. (D) Recurrent volvulus of the stomach into the chest is a serious condition that can lead to incarceration and gangrene. Every attempt should be made to repair this diaphragmatic hernia.

Answer 59

53. (B) The presentation itself should alert the clinician to the possibility of a pneumothorax (Fig 4–3). This condition is seen quite frequently with patients that are thin and tall. This lady presents with a catamenial pneumothorax syndrome.

Answer 60

54. (A) This is the first documented pneumothorax on this patient. The treatment of choice is insertion of a chest tube. If the air leak persists for more than 3 days or if she develops a recurrence after discharge, a thoracoscopy, resection of bullae and pleurodesis becomes the treatment of choice.

Answer 61

55. (A) The decision to operate in patients with aortic stenosis is based on transvalvular gradient. 50-mm gradient is termed critical aortic stenosis and the valve should be replaced in a symptomatic patient.

Answer 62

56. (B) Congestive heart failure. In patients with aortic stenosis, risk factors include a history of agina, stroke or TIAs, and a history of congestive heart failure, which indicates a compromised left ventricle. Of the three, congestive heart failure is the factor which is the greatest risk factor for patients undergoing surgery.

Answer 63

57. (E) Aortic insufficiency. This is the murmur of a patient with aortic insufficiency. Typically, these patients will be well compensated at rest but will have decreased cardiac output with exercise. These patients should be operated on.

Answer 64

58. (F) Aortic dissection. This describes a patient with Marfan syndrome, who are typically at risk for aortic dissection. With dissection you may preserve right radial pulse but lose femoral pulses.

Answer 65

1. (D) The treatment goal in these patients is to reestablish blood flow to the lower extremity. The treatment is based on the findings at angiogram. All the treatment options are valid and are used in treatment of the aortoocclusive disease. Patients with short-segment (TASCA) stenosis in common iliac artery are treated with angioplasty and/or stent placement and the patency results are expected to be comparable to surgery. In patients with long-segment stenosis and good risk patient treatment options would include aortobifemoral bypass. These procedures are long lasting. The long-term patency rates are reported to be 65–90%. Axillobifemoral bypass is utilized in patients with high risk and poor general condition. The patency rates for this group vary between 50–85% in 5 years. The patient described would be an ideal candidate for axillobifemoral bypass.

Answer 66

2. (C) The current indication for repair of abdominal aortic aneurysm in female includes aneurysm size 5 cm in acceptable risk patient. A United Kingdom small aneurysm study has increased the size that could be observed to 5.5 cm in male while in female it is acceptable to treat aneurysm at 5 cm size for acceptable risk. Any aneurysm with associated complication should be treated; just the presence of intramural thrombus does not justify repair. Asymptomatic 5.5-cm aneurysm should be treated in all patients, male or female, at acceptable cardiac risk. Patients with 2-cm aneurysm of iliac artery without any symptoms and complications should be observed; as the risk of surgery is higher than risk of observation till they reach to 4 cm. In patients, not in child-bearing age, 1.5-cm splenic aneurysm could be observed.

Answer 67

3. (B) An 8-cm aneurysm carries significant mortality which exceeds 50% in 1 year from aneurysm related death if observation or medical management is chosen as treatment option. It would be appropriate, if the neck size is greater than 1.5 cm and diameter is less than 26 mm, without any significant thrombus or calcification in the neck. This patient does well at least on mid term follow-up. They have lower perioperative morbidity compared to traditional open repair. Open repair with given cardiac history would carry high morbidity and morotality. b-blocker therapy would be indicated for his cardiac condition but is not a standard therapy for aneurysm.

Answer 68

4. (D) Mortality associated with aortic aneurysm is usually around 0–3%. A ruptured AAA carries mortality in range of 60–80% depending on presentation. Risk of large-bowel ischemia with ruptured AAA is about 10%. The first investigation with patients where colonic ischemia is suspected is to perform sigmoidoscopy. All other investigations may be done but none of them would be the primary investigation for the suspected pathology.

Answer 69

5. (E) Ruptured AAA carries a mortality of 40–50%. It is true that only 50% of all ruptured AAA reaches the hospital. Free peritoneal rupture carries a very high mortality. Thoracotomy is not the standard approach for proximal aortic control. Ruptured AAA can be treated with endovascular grafts. Preoperative hypotension is a good predictor of poor outcome but cardiac arrest is associated with 100% mortality in most of the studies. Answers and Explanations

Answer 70

6. (A) Neurological events are associated with extracranial carotid artery in about 60%. Fourty percent may have extracranial/intracranial cause for neurological events, which includes cardiac emboli, arch of aorta as source of emboli; intracranial bleed may be more than just a TIA. It is not always that platelet emboli are the cause of TIA, it could be due to atheroma. It is not always attributed to thrombus.

Answer 71

7. (D) Asymptomatic carotid artery stenosis is only treated surgically if it is greater than 70% stenosis. The risk reduction with surgical treatment is favorable with 70% stenosis when compared to nonoperative treatment. Any symptomatic stenosis is an indication for surgical intervention including ulcerated plaque. Any amount of stenosis with unstable angina would need appropriate workup for cardiac risk prior to carotid intervention. Carotid endarterectomy and CABG are viable options if they are left main disease and have undergone coronary angiogram. In this patient the most appropriate treatment is option to perform coronary angiogram and possible carotid stenting if feasible. Role of anticoagulation to prevent recurrent TIA is not well established. Aspirin and clopidogrel bisulfate are appropriate options for TIA.

Answer 72

8. (D) Recurrent stenosis is secondary to intimal hyperplasia but it occurs in first two years. If more than two years, it is progression of disease and it does not carry high risk for embolization, so it is reasonable to observe it. It is also a surgery which carries higher stroke rate and morbidity with nerve injury which is in range of 7%. Patient is treated with antiplatelet therapy which includes aspirin and clopidogrel bisulfate. Anticoagulation with warfarin is not a standard therapy. It is appropriate to treat the opposite side with 80% carotid stenosis. Angiogram and angioplasty is an option but if the stenosis is significant and symptomatic. Priority in this case would be to treat the opposite side.

Answer 73

9. (B) The treatment for symptomatic carotid artery stenosis greater than 70% is carotid endarterectomy. Since patient has left cerebral symptoms, it would be appropriate to treat that side first. Patient would need bilateral carotid endarterectomy but symptomatic side would be the first one to be operated. Heparin has no significant role in preventing stroke. Aspirin is a part of therapy but would not constitute a primary modality for treatment.

Answer 74

10. (E) In recovery room, the immediate approach would be to explore the patient. The cause for immediate stroke is usually technical and is most likely reversible if treated early on. All investigations are valid options once the technical cause is addressed and it would not be a primary option.

Answer 75

11. (B) All the listed conditions may result in isolated digital ischemia. In this age group, atheroembolism is the most likely diagnosis in a man. The atheroma is derived from an occult aortic aneurysm or a proximal ulcerative atherosclerotic lesion. This plaque or ulcer can be any part of the vascular tree proximal to the ischemic toe. Cardiac emboli also are common in this age group but are a less likely cause in the absence of previous MI, arrhythmia, or valvular disease.

Answer 76

12. (E) This patient suffers from thromboangiitis obliterans (Buerger’s disease), a disease found most frequently in white men between 20 and 40 years of age. It is a form of panvasculitis involving the artery, vein, and nerve. Heavy tobacco smoking is strongly associated with this disease. Early in the course of the disease, there is involvement of the superficial veins, producing recurrent migratory superficial phlebitis. The distribution of arterial involvement is usually segmental, involving the peripheral arteries. In the lower extremities, the disease occurs generally beyond the popliteal arteries and distal to the forearm in the upper extremities. As long as ulceration or gangrene is confined to a digit, amputation should be postponed as long as possible unless rest pain or infection cannot be otherwise controlled. Bypass surgery is rarely indicated, and long-term anticoagulation has not been of much benefit. The most important aspect of treatment is cessation of smoking, which can halt progression of the disease. 228 10: Vascular

Answer 77

13. (B) Although aortography, CT, and MRI can all establish the diagnosis of abdominal aortic aneurysm, ultrasound remains the best screening test. It is the preferred method for making the initial diagnosis, because it is reliable, inexpensive, and noninvasive. Aortography is used infrequently because of the small but definite risk it entails and because diagnosis can be made by other means. Once the aneurysm meets the criteria for repair, then a CT scan is done preoperatively to establish the true size and to delineate the aneurysm more accurately. Plain films of the abdomen are inaccurate in establishing the diagnosis.

Answer 78

14. (A) Operative treatment is indicated if the diameter of the stenosis is greater than 60%, even if the patient is asymptomatic. The value of prophylactic carotid endarterectomy, for hemodynamically significant carotid stenosis, decreases the incidence of subsequent cerebral ischemic events if performed with morbidity and mortality rates under 4%. Several studies including asymptomatic carotid artery surgery (ACAS) have shown that surgical treatment is superior to medical management if the stenosis is 60% or greater. The ACAS trial has shown the benefits of surgical treatment over medical management if the stenosis is greater than 60%. However, there are no data to support the use of carotid endarterectomy in asymptomatic patients with stenosis of less than 60%. If ischemic events eventually develop, stroke can be the presenting symptom.

Answer 79

15. (C) This patient is experiencing recurrent left hemispheric TIA with a hemodynamically significant stenosis of the left carotid artery. This is clearly an indication for surgery because operative management is superior to aspirin in symptomatic carotid bifurcation disease with stenosis greater than 70%. Oral anticoagulants may decrease the incidence of TIAs but not of completed strokes, and they are associated with a considerable risk of hemorrhage. Carotid endarterectomy, and not carotid artery bypass, is the surgical procedure of choice. Surgical treatment must be performed before and not after major neurologic deficits are produced from cerebral infarction.

Answer 80

16. (D) Popliteal artery entrapment syndrome consists of intermittent claudication caused by an abnormal relation of that artery to the muscles, usually the medial head of the gastrocnemius muscle. As a consequence of developmental abnormalities, the popliteal artery may be compressed by the medial head of the gastrocnemius muscle, resulting in ischemia of the leg at an unusually early age. On examination, the pulses may be diminished or absent, but they may also be normal and be made to disappear on dorsiflexion of the foot. Angiography is essential to establish the diagnosis.

Answer 81

17. (C) Phlegmasia cerulae (blue) dolens, indicates that major venous obstruction has occurred. The standard treatment for postoperative thrombosis includes bed rest and anticoagulation. Venous thrombectomy may be indicated when impending gangrene is noted. Vena caval filters are inserted in patients with established pulmonary emboli, but they may be considered as a prophylactic measure when iliofemoral thrombosis is massive. They are also inserted as an adjunct to venous thrombectomy along with creation of an arteriovenous fistula to prevent the venous system from rethrombosing. Thrombolysis of major venous thrombi requires placement of a multihole pigtail catheter inside the thrombus and administration of tPA, including systemic heparinization and is therefore contraindicated postoperatively.

Answer 82

18. (D) A through clinical evaluation followed by a venous duplex examination are the two most important steps in managing varicose vein of the lower extremity. An asymptomatic patient without complications of phlebitis, ulceration, or hemorrhage should be treated with compression stocking. Duplex evaluation will help map the valvular incompetence of the superficial and deep system including the perforators that guide the extent of the initial surgical intervention, and also investigate if these are primary or secondary varicosities. Sclerotherapy is an alternative to surgery but in the presence of saphenofemoral, saphenopopliteal, or perforator reflux is associated with a high incidence of recurrence and complications. Answers: 6–18 229

Answer 83

19. (C) A traumatic AV fistula results from a penetrating injury to adjacent artery and vein, permitting blood flow from the injured artery into the vein. The iatrogenic injury in this case occurred during cardiac catheterization. Femoral artery thrombosis results in signs of limb ischemia. A bruit is usually not heard with venous insufficiency. Traumatic pseudoaneurysm presents as an enlarging pulsating mass. Once the diagnosis of AV fistula is made, an angiogram is performed, and surgical repair (division of the fistula and reconstruction of the artery and preferably of the injured vein as well) is carried out.

Answer 84

20. (C) Effort thrombosis, also called Paget-von Schroetter syndrome, is the development of thrombosis of the axillary-subclavian vein as a result of injury or compression. It occurs primarily in young athletes and is disabling. When these patients are seen early, thrombolytic therapy is the first step in management and is followed by a venogram to detect correctable lesions. If effort thrombosis is associated with thoracic outlet syndrome, then thrombolytic therapy should be followed by cervical rib resection. If the condition is chronic, thrombolytic therapy might not be successful; these patients usually respond to limb elevation and anticoagulation.

Answer 85

21. (B) Stump prognosis can be judged by transcutaneous oxygen monitoring. Doppler is not fully reliable to select the level of transection, because it cannot calculate the quantity of vascular flow. Transcutaneous oxygen (PO2 >40 mm Hg) offers a fairly accurate prediction of a favorable result; although, Doppler fails to confirm a patient pulse at the level of transection. On the other hand, a duplex evaluation with blood flow of more than 50 cm/s is also a fairly accurate predictor for stump prognosis. The level of transection is 13–15 cm below the level of the medial condyle of the tibia.

Answer 86

22. (A) If claudication is the only symptom, elective vascular reconstruction is considered only if claudication is disabling and interferes with dayto-day activity. Because the risk of gangrene, occurring in a patient who has only claudication, is small, this alone does not constitute a clear-cut indication for operation. Vigorous exercise programs have resulted in marked improvement in claudicants. Revascularization surgery is usually reserved for rest pain or tissue loss (nonhealing ulcer, gangrene). Addition of a phosphodiastraze inhibitor, cilostazol (pletal), or pentoxiphyline (trental) can help increase the claudication distance. It should also be kept in mind that an angiogram is not indicated for claudication. An initial evaluation with noninvasive vascular studies is the investigation of choice. Angiogram is only requested if the decision is made to intervene surgically.

Answer 87

23. (D) Splenic artery aneurysms are rare and are most frequently caused by medial necrosis. Small asymptomatic aneurysms caused by atherosclerosis are more commonly incidental findings at autopsy. Larger (>3 cm) aneurysms predominate in women and characteristically may rupture during late pregnancy. Rupture may be preceded by an initial warning bleed into the retroperitoneum, with massive bleeding following after 1 or 2 days.

Answer 88

24. (E) Patients with a diabetic foot may have localized arterial occlusion involving the popliteal artery and its branches, usually sparing the femoral artery. Although patients have gangrene of the toes, there may be a palpable pulse in the foot. In the presence of localized disease, trophic ulcers and even gangrene of the toes may respond to local foot care, and major vascular reconstruction or amputations are not required. The trophic ulcers have punched sides. Patients may not realize the gravity of localized gangrene with spreading cellulitis, which develops because of the neurotropic nature of the lesions with the absence of pain sensation.

Answer 89

25. (C) Lymphangiosarcoma is a rare complication of long-standing lymphedema, most frequently described in a patient who has previously undergone radical mastectomy (Stewart-Treves syndrome). It usually presents as blue, red, or purple nodules with satellite lesions. Early metastasis, mainly to the lung, may develop if it is not recognized early and widely excised. Lymphedema is a complication of radical mastectomy and presents as diffuse swelling and nonpitting edema of the limb. Lymphangitis and hyperkeratosis are complications of lymphedema.

Answer 90

26. (B) The most accurate method of confirming the diagnosis of venous thrombosis is the injection of contrast material to visualize the venous system (venography). However, this method is invasive and time-consuming and must be done in the radiology suite. Venous duplex ultrasound is noninvasive, can be done bedside, and has a sensitivity and specificity of 96 and 100%, respectively. The other methods listed are used less often in certain selected patients.

Answer 91

27. (B) The mainstay of treatment of chronic venous insufficiency and its complication, venous stasis ulceration, is conservative management. Elastic stocking support, frequent elevation of the legs, and avoidance of prolonged sitting and standing is used for venous insufficiency in the absence of ulceration. If venous stasis ulcers develop, then paste boots (e.g., Unna’s boots) are used along with appropriate bed rest and foot elevation until the ulcer heals. Patients whose ulcers fail to heal after such conservative management may need perforator vein ligation. Skin grafting should be considered for chronic stasis ulcers that are large, and perforator incompetance has been treated. Venous reconstruction procedures, including valvuloplasty, can be useful for a selected group of patients, especially those with venous claudication to less than half a block, that have been treated with all the procedures above, including stripping and ligation. Unlike previous opinions, superficial venous stripping and ligation is not always contraindicated in the presence of chronic venous insufficiency and even previous history of deep vein thrombosis.

Answer 92

28. (E) The Trendelenburg’s test is a two-part test used to access the competency of the superficial and perforating veins. The legs are elevated to evacuate the veins, and pressure is applied to the saphenofemoral junction either by hand or tourniquet. The four possible results are: (a) negative/negative response if there is gradual filling of veins from below and continued slow filling after release of pressure, indicating absence of incompetent superficial and perforating veins; (b) negative/positive response if there is gradual filling of veins from below while there is rapid retrograde filling after release of pressure, indicating incompetent superficial veins only; (c) positive/negative response if there is rapid initial filling of the veins from below while only continued slow filling after the release of pressure, indicating incompetent perforators only; and (d) positive/positive response if there is rapid filling of the saphenous vein before and after release of pressure, indicating incompetent superficial and perforating veins.

Answer 93

29. (D) The main treatment of DVT is adequate anticoagulation. However, if pulmonary embolism develops during anticoagulant therapy or if there is contraindication to anticoagulation, the insertion of an IVC filter is indicated either to prevent occurrence of or to offer prophylaxis against recurrence of pulmonary embolism (Fig. 10–4). Observation alone leaves the patient unprotected against pulmonary embolism, and operative thrombectomy is reserved for limb salvage in the presence of impending venous gangrene. Obviously, if anticoagulation is contraindicated (as in the patient presented), thrombolytic therapy cannot be used.

Answer 94

30. (A) The relatively benign course of intermittent claudication has been well established. The risk of gangrene developing within 5 years in an extremity with claudication as the only symptom is only about 5%. The patient must be encouraged to stop smoking, to exercise, and be placed on a diet that lowers cholesterol.

Answer 95

31. (D) The occurrence of bowel movements during the first 24–72 hours after repair of an abdominal aortic aneurysm (especially if the hemoccult test is positive), should raise suspicion for ischemic colitis. It may develop as a result of interruption of flow to the inferior mesenteric artery with inadequate collateral circulation from either the superior mesenteric artery or the iliac arteries. Aortoduodenal fistula is a late complication of aneurysm repair. Pseudomembranous enterocolitis occurs late in the postoperative course.

Answer 96

32. (D) Popliteal aneurysms are usually arteriosclerotic and are bilateral in at least 50% of cases. Any popliteal aneurysm twice the size of the normal artery is an indication for surgical repair. Although often asymptomatic and small, they should be treated surgically because of their propensity to produce limb-threatening ischemia related to thrombosis or embolism. Spontaneous rupture and/or nerve compression are rare complications of a popliteal aneurysm. The ideal repair consists of ligation of the aneurysm, including its branches and a bypass to the open distal vessels.

Answer 97

33. (B) The presence of acute vascular collapse with history of abdominal or flank pain and associated pulsating abdominal mass is characteristic of a ruptured abdominal aneurysm. Operation should be performed as quickly as possible, because the first priority is to control the hemorrhage. No time should be lost in obtaining diagnostic studies, because these patients often crash in the radiology suite. These patients should not be resuscitated aggressively, because an increase in systolic pressure will only cause more intra-abdominal hemorrhage.

Answer 98

34. (E) The clinical picture presented is that of a subclavian artery stenosis resulting in subclavian steal syndrome, represented by vertebrobasilar symptoms and extremity ischemia. The symptoms are due to a decrease of posterior circulation (vertebral artery) blood flow. Claudication occurs more commonly than ischemic findings. Most patients have no triggering events, and the symptoms are not readily reproducible. Carotid subclavian bypass restores the circulation beyond the stenotic area and corrects the steal syndrome. Ligation of the vertebral artery will correct the steal syndrome but will not improve the circulation of the arm. Anticoagulation has no role in the treatment of this entity. Other treatment options include subclavian artery transposition, axilloaxillary bypass, and subclavian artery angioplasty. Coarctation of the aorta results in pulse and pressure difference between the upper and lower extremities.

Answer 99

35. (D) Spontaneous thrombophlebitis in this age group is unlikely. Plantaris or gastrocnernius tear may occur during physical exertion involving running or walking, causing a sharp pain in this region. After resolution of a hematoma in this region, it may be difficult to exclude cellulitis if there is any question that the integrity of the skin has been damaged. In superficial thrombophlebitis, there is tenderness along the distribution of the long or short saphenous veins. A tear of the medial lemniscus of the knee joint is detected by tenderness over the medical aspect of the knee joint during flexion and internal rotation of the knee joint (McMurray sign).

Answer 100

36. (A) Patients with atrial fibrillation are more likely to develop emboli to different sites throughout the body. Nonocclusive ischemic disease is characterized by spasm of the major mesenteric arterial vessels, with a characteristic beading effect. Early recognition may result in improvement with direct intra-arterial infusion of papaverine (which causes vasodilation), thus avoiding operative intervention.

Answer 101

37. (E) Clinical findings of peritoneal irritation and leukocytosis in patients with suspected visceral ischemia indicate necrosis of ischemic bowel. Immediate arteriography is required to establish the diagnosis and initiate treatment to restore circulation before massive bowel infarction, 232 10: Vascular acidosis, and possible perforation occur. The most likely diagnosis is a mesenteric embolus arising from the heart, especially in the presence of atrial fibrillation. The catheter should be left in place to allow papaverine infusion to an area of borderline ischemic bowel.

Answer 102

38. (C) Among all causes of renovascular hypertension, FMD responds best to angioplasty. Intermediate results of PTA for FMD are similar to those of bypass. PTA has lower morbidity, causes less discomfort, and is less expensive. Recurrence can be treated by repeated PTA.

Answer 103

39. (C) The heart is the origin of about 90% of lower extremity emboli. The causes are usually mitral stenosis, atrial fibrillation, or MI. A rare source of left atrial emboli is a left atrial myxoma. The remaining 10% arise from ulcerated plaques in the aorta or peripheral arteries. Paradoxical emboli arising from the venous system may reach the arterial circulation through a patent foramen ovale.

Answer 104

40. (D) Arterial emboli usually lodge proximal to bifurcations, the most common site being the common femoral artery.

Answer 105

41. (A) Once the diagnosis is made clinically, heparin is administered intravenously to prevent the development of thrombi distal to the embolus. Then embolectomy can be done in most instances under local anesthesia. Arteriography to confirm what is already clinically apparent only delays the needed surgical procedure. If there is a doubt, duplex evaluation will help confirm the diagnosis. Lumbar sympathectomy locks are of dubious value. In patients who have known occlusive disease, absent pulses in the contralateral extremity, absence of clinical features of hyperacute ischemia would be best managed by an angiogram and thrombolytic infusion.

Answer 106

42. (A) Patients with combined segmental occlusive disease require correction of proximal hemodynamically significant disease before distal (infrainguinal) bypass. Only about 20% of patients undergoing aortofemoral reconstruction in the presence of superficial femoral artery occlusion will subsequently require femoropopliteal bypass. Combined procedures should be reserved for patients with severe lifethreatening ischemia. Lumbar sympathectomy and vasodilator therapy are ineffective in treating severe arterial occlusive disease.

Answer 107

43. (C) Most patients are unaware of their abdominal aneurysm until it is incidentally discovered by their physician. The importance of careful deep palpation of the abdomen cannot be overemphasized. On occasion, these aneurysms may expand, causing abdominal or back pain, and may even leak or rupture, mimicking other acute intra-abdominal conditions. Signs and symptoms of acute ischemia in the lower extremities are rare and usually follow thrombosis or embolization from an abdominal aneurysm.

Answer 108

44. (B) Leriche syndrome consists of the manifestations of aortoiliac occlusive disease and includes thigh and buttock claudication, atrophy of the leg muscles, diminished femoral pulses, and impotence in men.

Answer 109

45. (B) The Nicoladoni-Branham sign can be elicited in some patients with an AV fistula. Occlusion of the fistula or the artery proximal to the fistula may result in slowing of the heart rate. By this compression, the peripheral resistance is increased, venous return is decreased, and the pulse rate falls.

Answer 110

46. (B) Peripheral nerve endings are the tissues most sensitive to anoxia in the extremity. Therefore, paralysis and paresthesia are most important when evaluating an extremity with acute arterial occlusion. The second most sensitive tissue is the muscle. This is why an extremity with paralysis and paresthesia will develop gangrene if circulation is not restored. Gangrene is less likely to occur if signs of ischemia are present, but motor and sensory functions are intact.

Answer 111

47. (E) The use of an extra-anatomic bypass (axillobifemoral) is indicated in the presence of “hostile” abdomen (infection, dense and severe adhesions, tumors) or if the patient is too sick to undergo an abdominal operation. If a previously placed graft is contaminated (infection, Answers: 30–47 233 aortoenteric fistula), the graft must be removed, and the enteric defect must be closed. Although some surgeons advocate removing the infected graft and replacing it in situ with a new graft, the safest approach remains the extra-anatomic route to restore circulation to the lower extremities (axillobifemoral bypass).

Answer 112

48. (C) Compartment syndrome can occur following repair of vascular injuries, especially if ischemia time is more than 6 hours or if there have been substantial periods of shock. Other instances include the combination of arterial and venous injury and the presence of concomitant soft-tissue crush injury or bone fracture. Compartment swelling and tenderness, pain disproportionate to the physical findings, paresthesia, and weakness are all clinical signs of compartment syndrome and require urgent surgical decompression. A palpable pulse does not rule out the presence of a compartment syndrome, because compartment pressures are high, even before loss of a palpable pulse.

Answer 113

49. (C) Rapid warming of the injured tissue is the most important aspect of treatment. The frozen tissue should be placed in warm water, with a temperature in the range of 408–448ºC. Dry heat or hot water carries the risk of thermal injury because of decreased sensation in the injured part. Opening of blisters and debridement of devitalized tissue are contraindicated. Demarcation of gangrenous areas should be carefully observed, often for several weeks, before amputation is performed. The extremity should be elevated, tetanus prophylaxis should be administered as indicated, and antibiotics should be given in the presence of open wounds.

Answer 114

50. (A) Carotid body tumors are usually 3–4 mm in size and are located at the carotid bifurcation. They arise from nests of chemoreceptor cells of neuroectodermal origin (carotid body). In normal individuals, the carotid body responds to a fall in PO2 and pH and to a rise in PCO2 and temperature to cause an increase in cardiac contraction, heart rate, and respiratory rate. Carotid body tumors are uncommon, slow growing, and highly vascular. Although large tumors may cause compression of the vagus or hypoglossal nerves, most tumors present as a palpable painless mass at the carotid bifurcation. The treatment is definitely excision whenever possible.

Answer 115

51. (D) PTA is technically successful in approximately 90% of iliac lesions with good patency rates. It is more successful for single short stenoses rather than multiple long stenosis or occlusions. The advantages of PTA is that it is less invasive than surgery, has a lower initial cost, has a shorter hospital stay, and lower morbidity, enables an earlier return to full activity, and the procedure can be repeated without an increase in morbidity or a decrease in clinical result. It is particularly useful for patients who are at high operative risks. The ideal procedure would be and angioplasty and stent placement.

Answer 116

52. (D) Aortography and renal ultrasound can detect the presence of renal artery stenosis, but they do not determine the functional significance of the lesion. IVP is not a sensitive enough test to detect the presence of renal artery stenosis. Arenal scan can show decreased flow (uptake) or decreased function of the affected kidney, but it, too, lacks sensitivity. The assessment of renal vein renin levels is a good diagnostic test to determine the physiologic significance of renal artery stenosis. It indicates whether the stenosis is significant enough to decrease the glomerular filtration rate and cause the release of renin. In addition, the opposite kidney should have suppression of renin secretion.

Answer 117

53. (D) Normal radiographic findings in the presence of severe knee trauma should raise suspicion for posterior dislocation of the knee, which is often associated with popliteal artery thrombosis. A careful vascular examination should, therefore, be made in such a situation. The presence of pain, pallor, and pulselessness (three of the five p’s) is indicative of severe ischemia. This patient should undergo urgent exploration for vascular repair. The other options are unlikely to cause the signs and symptoms presented.

Answer 118

54. (B) Amaurosis fugax, one type of TIA, is a manifestation of carotid bifurcation atherosclerotic disease. It is manifested by unilateral blindness, being described by the patient as a window 234 10: Vascular shade across the eye, lasting for minutes or hours. It is caused by microemboli from a carotid lesion lodging in the retinal artery, the first intracerebral branch of the internal carotid artery.

Answer 119

55. (C) Patients with sudden severe ischemia are prone to “ischemia-reperfusion” syndrome. With revascularization, there is sudden release of the accumulated products of ischemia into the circulation; namely, potassium, lactic acid, myoglobin, and cellular enzymes. Hyperkalemia, metabolic acidosis, and myoglobinuria (red urine, clear plasma) are the key features of the syndrome. Renal tubular acidosis results in myoglobin deposition in the renal tubules. Anticipation and early recognition require the induction of diuresis with mannitol, alkalinization of the urine to avoid precipitation of myoglobin in the renal tubules, and correction of hyperkalemia.

Answer 120

56. (D) Despite receiving optimal treatment for DVT, approximately 50% of the patients will develop the post-thrombotic syndrome. The recanalization of the deep veins will result in deformity and subsequently incompetence of the affected venous valves. Although patients with DVT can develop infections secondary to edema, these are usually located about the ankle and resolve with adequate treatment. Patients adequately treated for DVT are not at increased risk of developing pulmonary embolus. Neither the arterial circulation nor the superficial venous system are affected by the development of DVT. Young patients with iliofemoral thrombosis are best managed by thrombolytic infusion, which has been shown to preserve valvular function and decrease the incidence of postphlebitic syndrome.

Answer 121

57. (A) The causes of graft failure can be divided into early and late. Although early failure of vein grafts is usually attributed to either technical error or inadequate outflow tract, late failure is usually related to progressive proximal or distal atherosclerotic disease. Other less common causes of late graft failures include— local stenotic areas from trauma or endothelial damage, valve stenosis from fibrosis, and venous aneurysms and subsequent thrombosis. Intimal hyperplasia is a rare cause of late failure.

Answer 122

58. (C) Occlusion or stenosis of the subclavian artery proximal to the origin of the vertebral artery results in the “subclavian steal” syndrome. In response to decreased pressure in the distal subclavian artery, especially in instances in which increased perfusion is needed, there is reversal of flow in the vertebral artery. The clinical picture is that of vertebrobasilar symptoms in association with upper extremity exercise. Although this phenomenon is sometimes seen on duplex scanning or angiography, evolution into a clinical syndrome is relatively rare. The other mentioned options do not result in retrograde flow in the vertebral artery.

Answer 123

59. (C) Lymphedema is classified by etiology—primary versus secondary. Primary lymphedema is divided into congenital, praecox, and tarda, depending on the age of onset. The diagnosis of Milroy disease is reserved for patients with familial lymphedema in which clinical factors are present at birth or noticed soon thereafter. Lymphedema is classified as praecox if the age of onset is between 1 and 35 years. Meigs’ disease is the familial form of primary lymphedema praecox. If the onset of primary lymphedema is after 35 years of age, it is called lymphedema tarda. Secondary lymphedema usually results from a disease process that causes obstruction of the lymphatic system.