Pestana Chap 7 - Vascular Surgery

Question 1

What is subclavian steal syndrome?

Answer 1

An arteriosclerotic plaque at the origin of the subclavian (before the takeoff of the vertebral) allows enough blood supply to reach the arm for normal activity, but does not allow enough to meet higher demands when the arm is exercised. When that happens, the arm sucks blood away from the brain by reversing the flow in the vertebral

Question 2

How does a patient with subclavian steal syndrome present? If a patient had just the vascular symptoms of subclavian steal syndrome, what diagnosis would he have?

Answer 2

1) Clinically the patient describes claudication of the arm (coldness, tingling, muscle pain) and posterior neurologic signs (visual symptoms, equilibrium problems) when the arm is exercised
2) Vascular symptoms alone would suggest thoracic outlet syndrome, but the combination with neurologic symptoms identifies the subclavian steal

Question 3

What is the diagnostic test for subclavian steal syndrome and what will it show? What is the treatment?

Answer 3

1) Duplex scanning is diagnostic when it shows reversal of flow
2) Bypass surgery cures it

Question 4

With what symptoms does an abdominal aortic aneurysm usually present? How is it normally found?

Answer 4

AAA is typically asymptomatic, found as a pulsatile abdominal mass on examination (between the xiphoid and the umbilicus) or found on x-rays, sonograms, or CT scans done for another diagnostic purpose, usually in an older man

Question 5

What is the key to management of abdominal aortic aneurysm (AAA)? If it is found by physical exam, what is needed next for precise measurements?

Answer 5

Size is the key to management, and thus if the aneurysm was found by physical exam, sonogram or CT scan is needed to provide precise measurements

Question 6

When do abdominal aortic aneurysms require surgery?

Answer 6

1) If the aneurysm is 4 cm or smaller, it can be safely observed and the chances of rupture are almost zero
2) If it is 5 to 6 cm or larger, the patient should have elective repair because the chance of rupture is very high
3) Aneurysms that grow 1 cm per year or faster also need elective repair

Question 7

How is elective repair of an abdominal aortic aneurysm performed?

Answer 7

Elective repair of an AAA has traditionally been done by open laparotomy, but percutaneously inserted vascular stents are now becoming popular

Question 8

Why do you want to do surgery before an abdominal aortic aneurysm ruptures?

Answer 8

Surgery for a ruptured abdominal aortic aneurysm carries very high morbidity and mortality, thus efforts are made to predict and anticipate rupture, and not wait for it to occur

Question 9

What does a tender abdominal aortic aneurysm indicate?

Answer 9

A tender abdominal aortic aneurysm is going to rupture within a day or two, and thus immediate repair is indicated

Question 10

What does excruciating back pain in a patient with a large abdominal aortic aneurysm indicate?

Answer 10

1) The aneurysm is already leaking
2) Retroperitoneal hematoma is already forming, and blowout into the peritoneal cavity is only minutes or hours away
3) Emergency surgery is required

Question 11

Is prophylactic surgery required for arteriosclerotic occlusive disease of the lower extremities? When is surgery done for arteriosclerotic occlusive disease?

Answer 11

1) Arteriosclerotic occlusive disease of the lower extremities has an unpredictable natural history (except for the predictable negative impact of smoking), and therefore there is no role for “prophylactic” surgery
2) Surgery is done only to relieve disabling symptoms or to save the extremity from impending necrosis

Question 12

What is the first clinical manifestation of arteriosclerotic occlusive disease of the lower extremities? What is the next step in management if this manifestation does not interfere significantly with the patient’s lifestyle? What other things can be done to help a patient in the long run?

Answer 12

1) Pain brought about by walking and relieved by rest (intermittent claudication)
2) If the claudication does not interfere significantly with the patient’s lifestyle, no workup is indicated
3) Cessation of smoking, a program of exercise, and the use of cilostazol can help the patient in the long run

Question 13

What does the workup of disabling intermittent claudication start with? When is this disease not amenable to surgery? When is it and what should be done to prepare for surgery?

Answer 13

1) Doppler studies looking for a pressure gradient, also known as establishing an ankle-brachial index
2) If there isn’t a gradient between blood pressure measured in the arm and at various places in the leg (an ankle-brachial index of 1), then the disease is in the small vessels and not amenable to surgery
3) If there is a significant gradient (ankle-brachial index of 0.8 or less), follow with CT angio or MRI angio to look at the anatomy and plan the revascularization

Question 14

What is the most durable option of surgery for intermittent claudication? What is the most sophisticated surgical option for these patients?

Answer 14

1) Bypasses, for which saphenous vein grafts are harvested from the patient and reversed, remain the most durable option
2) Obviously, large-diameter arteries require prosthetic materials. Angioplasty and stents, once reserved for short segments, have exploded as the most sophisticated current option for most patients. Stents can be impregnated with medication, hooked to each other, or composed of a nickel alloy with shape memory triggered by temperature. Presurgery, nickel alloy stents are stored in the freezer in the closed position. Once inserted percutaneously where they need to go, the blood warms them, and they deploy by themselves

Question 15

What is the penultimate stage of arteriosclerotic occlusive disease of the lower extremities? What is the clinical manifestation of this stage? What does physical exam show?

Answer 15

1) Rest pain (the ultimate is ulceration and gangrene)
2) The clinical picture is rather characteristic. The patient seeks help because he “cannot sleep.” It turns out that pain in the calf is what keeps him from falling asleep. He has learned that sitting up and dangling the leg helps the pain, and a few minutes after he does so, the leg that used to be very pale becomes deep purple
3) Physical exam shows shiny atrophic skin without hair, and no peripheral pulses
4) Workup and therapy are the same as for any intermittent claudication

Question 16

When is arterial embolization from a distant source seen in patients? How do these patients present?

Answer 16

1) Atrial fibrillation (a clot breaks off from the atrial appendage) or those with a recent MI (the source of the embolus is the mural thrombus)
2) The patient suddenly develops a painful, pale, cold, pulseless, paresthetic, and paralytic lower extremity (if you substitute “poikilothermic” for “cold,” you have all the “P”s that are the mnemonic)

Question 17

How urgently should evaluation of arterial embolization from a distant source be done? What test will locate the point of obstruction?

Answer 17

1) Urgent evaluation and treatment should be completed within 6 hours
2) Doppler studies

Question 18

How is early incomplete occlusion of arterial embolization from a distant source treated? What is the treatment for complete obstructions? What is added if several hours have passed before revascularization?

Answer 18

1) Clot busters
2) Embolectomy with Fogarty catheter
3) Fasciotomy

Question 19

Which patient is at risk for developing a dissecting aneurysm of the thoracic aorta? How does an episode present? What is characteristic of the pulses in the upper extremities in some cases?

Answer 19

1) Dissecting aneurysm of the thoracic aorta occurs in the poorly controlled hypertensive
2) The episode resembles an MI, with sudden onset of extremely severe, tearing chest pain that radiates to the back and migrates down shortly after its onset
3) There may be unequal pulses in the upper extremities

Question 20

What is seen on x-ray of a dissecting aneurysm of the thoracic aorta? What tests are done to rule out MI? By which means should definitive diagnosis be done?

Answer 20

1) Wide mediastinum
2) EKG and cardiac enzymes
3) Definitive diagnosis should be sought by noninvasive means (to avoid high-pressure injection needed for the aortogram). MRI angiogram and transesophageal echocardiogram have been used, but the best option is probably a spiral CT scan (also known as a CT angiogram)

Question 21

How does management differ in dissection of the ascending aorta vs descending aorta?

Answer 21

1) As a rule (riddled with exceptions), dissections of the ascending aorta are treated surgically, whereas those in the descending are managed medically with control of the hypertension in the ICU
2) In the former, the aortic valve may have been damaged and thus may require repair
3) In the latter, the devastating consequences of interrupting the blood supply to the spinal cord make surgery a risky proposition, and it is rarely done

Question 22

What are two methods of biopsy to prove if there is cancer somewhere in the body?

Answer 22

If we think that there is a cancer somewhere inside the body, we have two options to prove it: FNA or core biopsy

Question 23

What are the advantages of FNA? What are the disadvantages of FNA?

Answer 23

1) It is a very simple and inexpensive way of obtaining a biopsy
2) This method denies the pathologist a view of the tissue architecture, so that many times a diagnosis cannot be made. A negative answer does not signify no cancer

Question 24

In which two cases is FNA contraindicated?

Answer 24

1) Do not do an FNA if you think there is a hemangioma in the liver: Should the patient take a deep breath when the needle is in, it could slice the hemangioma, leading to fatal bleeding
2) Do not do an FNA of a testicular mass. These are almost invariably malignant and will quickly spread through the needle tract

Question 25

When a suspected cancer is on the skin or otherwise accessible, what options are available for biopsy?

Answer 25

In addition to FNA and core biopsy, you can also do incisional verses excisional biopsy

Question 26

When do you choose to use incisional vs excisional biopsy?

Answer 26

1) The key criterion is the size of the lesion
2) Tiny ones can be removed in toto
3) On bigger ones we should only take a sample, by cutting a little piece, preferably at the edge of the lesion