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Flashcards in Vascular Surgery - NMS Casebook Deck (41):
1

How would you evaluate a patient suspected of having a transient ischaemic attack? 

  1. An examination for carotid bruits, residual neurologic deficit and evidence of cardiac disease - especially murmurs that might indicate an embolic source is necessary. 
  2. If murmur is present then an echocardiogram would be appropriate 
  3. In addition a duplex ultrasound study of the carotid vessels to check for stenosis or irregular plaque morphology is essential in all patients 

2

A patient has a diagnosis of a TIA. The necessary work-up is performed and duplex ultrasound studies of the carotid vessels reveals an 80% stenosis of the left internal carotid artery. What are your treatment options? 

  • Two therapeutic choices are available 
    1. Medical treatment with aspirin 
    2. Surgical therapy involving carotid endarterectomy 
  • It is demonstrated that for a stenosis of 70% or more in the internal carotid artery with ipsilateral symptoms, surgical treatment results in significant advantage in stroke prevention. 

3

What are the other indications for carotid endarterectomy?

  1. Ipsilateral hemispheric neurological symptoms (amaurosis fugax, transient ischemic attack, completed stroke with major neurological recovery with greater than 70% internal carotid stenosis
  2. Asymptomatic carotid bruit and greater 70% internal carotid stenosis

4

What are some of the complications related to a carotid endarterectomy? 

  1. Injury to the hypoglossal nerve
  2. Injury to the vagus nerve
  3. Injury to marginal branch of the facial nerve 

5

What preoperative evaluation would you undertake for a carotid endarterectomy? 

  1. General medical condition of the patient should be satisfactory
  2. Blood pressure should be well controlled - to avoid wide intraoperative BP swings
  3. An appropriate cardiac evaluation is necessary before surgery 
  4. A carotid artery arteriogram is obtained to describe the anatomy of the lesion in more detail 

6

What are the basic steps for a carotid endarterectomy? 

  1. Incision is made along the sternocleidomastoid muscle - dissection performed down to carotid sheath
  2. Sheath is opened - vagus nerve is protected, carotid artery is isolated - avoiding denervation of the carotid body
  3. Internal carotid artery is exposed to level of the hypoglossal nerve - must not be injured
  4. Patient is heparinized - vessels are clamped
  5. Vessels are opened and plaque is dissected from underyling vessel media and adventitia 
  6. Vessel is then closed with or without a patch - neck is closed 

7

A 65 year old man comes to A&E with a history of sudden onset of pain in his right leg - and difficulty in moving the leg. He says the leg has been normal up until now. There is an absence of pulses in his lower extremities - including the femoral pulse in the right leg. Pulses are normal in the left leg. The right leg appears cool and cyanotic - decreased sensation throughout. All muscle groups are weak. What is your diagnosis? 

  • The patient probably has an acute arterial embolus in his right leg
  • Absence of a right femoral pulse and presence of a left femoral pulse indicate that the embolus is most liekly at the right iliofemoral level

8

What is most important in terms of immediate management of an acute vascular event in the leg? 

  1. Time 
    • With an acute arterial embolus - the time interval between the ischemic event and clinical presentation are critical to successful limb salvage. 
    • Revascularization more than 6 hours after ischemia may result in a severely impaired limb or even require amputation. 

9

For an acute arterial embolus in the leg what is appropriate treatment? 

  1. Administer heparin immediately 
  2. Proceed to operating room to allow the earliest revascularization 

10

For an acute arterial embolus what surgical procedure is necessary? 

  • A balloon catheter embolectomy is the procedure of choice 
  • It involves the following steps 
    1. Femoral artery is exposed and opened under local anesthesia and proximal embolus is extracted using a balloon catheter 
    2. Typically, thrombus is also removed from the distal vessels. An intraoperative arteriogram can then be performed to assess the adequacy of thrombus removal. If necessary it is possible to lyse the thrombus further with intra-arterial thrombolytic therapy if there is residual distal, small arterial thrombus 
    3. Arteriotomy is closed - limb is then revascularized. 

11

Following an embolectomy your patient has good perfusion to the foot and toes - but now has developed an inability to dorsiflex the foot and tenderness in the calf. Explain. 

  • This is compartment syndrome. 
  • This condition is most common after revascularization of an acutely ischemic limb. 
    • It should be suspected in any patient who has an ischemic or traumatic injury to a muscle group that causes acute muscular edema 
  • Compartment syndrome is also termed as ''ischemia-reperfusion injury''.
    • Because many muscles are encased in an inelastic, fascial compartment, edema increases the volume - ultimately the pressure within the compartment.
    • As pressure increases, muscle perfusion decreases - resulting in further ischemic injury
      • Worsens edema 
    • As compartment pressure approaches 20-40 mmHg, irreversible ischemic injury of the muscles and nerves may occur. 

12

How would you manage compartment syndrome? 

  1. If you suspect compartment syndrome - do not wait for advanced symptoms such as motor or sensory loss, or loss of the distal arterial pulses
  2. In this case a fasciotomy should open all four compartments in the calf 
    1. muscles bulges out at excision, relieving the pressure and improving perfusion
    2. once the acute episode is resolved, a fasciotomy is typically closed with a split thickness graft
    3. during recovery, performance of physical therapy is important for maintenance of a full range of leg motion.

13

Outline your long term management for compartment syndrome following a fasciotomy

  • Most surgeons would place the patient on chronic anticoaguation therapy with warfarin
  • Once the patient recovers - echocardiography and other diagnostic techniques such as aortography or CT of throacic and abdominal aorta should be used in search for an embolic source 

14

What arteries in the legs are typically involved in atherosclerotic occlusions? 

  1. With intermittent claudication, popliteal and pedal pulses are often absent, indicating at least an occlusion of the superficial artery - typically at the adductor hiatus. 
  2. Most common location for occlusive disease of the lower extremity - if the femoral pulse is absent - significant aortoiliac disease may be present. 

15

What are the signs of peripheral vascular insufficiency? 

  1. Claudication - reproducible muscle pain cramping or weakness typically of the calf muscles. It occurs during exercise and is relieved by rest
  2. Rest pain - constant, severe, burning, forefoot pain
  3. Ischemic ulceration - painful, non-healing ulceration - typically on the malleoni and toes
  4. Gangrene - cyantoic, insensate tissue progressing to black tissue or wet gangrene if infection is present. 

16

A patient has symptoms of claudication but she has an absent femoral pulse on the left side. How would this affect your management? 

  1. A weak or absent femoral pulse suggests poor blood flow into the leg, which is strong evidence for aortoiliac occlusive disease. This occlusion could be the single cause of the patient's symptoms  or one of the several occlusions contributing to the symptoms
  2. Aortoiliac occlusive disease is generally more progressive than more peripheral occlusive disease
  3. Surgery is considered and treatment is more aggressive
  4. Important issues are the status of the femoral pulse on the opposite side, evidence of small distal emboli and impotence in males and claudication in other locations such as thigh or buttock 
  5. If symptoms progress, aortoiliac reconstruction either with balloon dilatation and/or stent placement or surgical vascularization will be necessary

17

If an arteriogram shows occlusion of the superficial femoral artery with distal reconstitution what is your management plan? 

A reversed or in situ saphenous vein graft from the common femoral artery to the popliteal artery is typically used to bypass the obstructions. 

18

If an arteriogram shows high grade stenosis of the iliac artery but patency of the lower extremity vessels what is your management plan? 

A surgical revascularization using a large diameter graft from the aorta to the femoral artery or by balloon dilatation and/or arterial stent placement is appropriate. 

19

If the arteriogram shows high grade stenosis of the iliac artery and occlusion of the superficial femoral artery, what is your manaement plan? 

A lower extremity revascularization in addition to the aortoiliac reconstruction may be necessary. The patient has multi-level disease - the two procedures may be performed at the same time or sequentially - the inflow (aortoiliac occlusions) can be treated first - revascularization may be sufficient to relieve the symptoms. 

20

If an arteriogram shows occlusion of the superficial femoral and popliteal arteries with distal reconstitution what is your management plan? 

Femoropopliteal bypass is indicated for such a case

21

What type of vessel disease to diabetics have? 

Typically, diabetics predominantly have tibial disease

22

After vascular bypass surgery what follow-up would you recommend? 

 

  1. Frequent duplex examinations of the graft to allow early detection of graft stenoses
  2. Start aspirin
  3. Advise control of serum lipids
  4. Provide education about foot care

23

A 61 year old man reports calf and thigh pain on exertion - which is relieved slowly by rest. He also complains of impotence, and he has smoked 1.5 packs per day for 30 years. Physical examination reveals absent femoral and lower extremity pulses bilaterally and stigmata of chronic vascular insufficiency in the lower legs. What is your diagnosis? 

Aortoiliac occlusive disease secondary to atherosclerosis (Leriche syndrome) 

24

How would you manage a patient with Leriche syndrome? 

  1. Lifestyle modification is appropriate if the operative risk for any procedure is prohibitive. However, without surgery, the patient will almost likely progress to amputation or death
  2. Percutaneous transluminal angioplasty (PTA) often performed at the time of angiography is ideal if the patient has a single short-segment iliac stenosis
  3. Aortobifemoral bypass - indicated in bilateral loss of femoral pulses 

25

Under what circumstances would you choose to do an axillofemoral bypass graft in a patient with aortoiliac occlusive disease? 

In a patient who is at poor risk, this alternate procedure avoids a large transabdominal maneuver. 

26

What part of an aortobifemoral bypass graft operation has the greatest cardiovascular risk? 

  1. During induction of anesthesia
  2. Times of hemorrhage or other stress 
  3. In this procedure the the heart is also at increased risk due to:
    1. Aortic clamping and unclaming 

27

After the aortobifemoral bypass graft operation to faciliate revascularization - you examine the patient's peripheral circulation - you notice a painful, cyanotic big toe that was not present preoperatively. What is it? 

  • ''Trash-foot''
    • The atheroembolization of fibrin, platelets or dislodged atherosclerotic debris - blocking small pedal or digital arteries and microvessels during unclamping. 

28

How would you manage ''trash-foot''? 

  • Heparinization followed by long-term antiplatelet therapy. 
  • Site-directed thrombolytic therapy may decrease the area of injury but is usaully contraindicated because of recent surgry (thrombolysis can result in massive bleeding at the operative site even weeks after surgery) 
  • The toe should be protected from injury and assessed for necrosis

29

What are the steps in the repair of an abdominal aortic aneurysm? 

  1. Exploration of abdomen with the retroperitoneum on the left side of the abdomen overlying the aorta revealed by reflecting the duodenum medially and exposing the aorta from the left renal vein to bifrucation
  2. Inferior mesenteric artery is controlled - IV heparin given - aorta and distal vessels are clamped - aorta is opened
  3. Thrombus is removed - prosthetic graft of Dacron is sewn to proximal and distal vessels to reestablish continuity 

30

What are the post-operative problems that are common following AAA repair? 

  1. Initial 1-2 days - patients will have large third space losses and extra fluid requirements 
  2. By the third day - patients will mobilise this fluid - require diuresis and restriction of IV fluids 
    • If not done then may develop respiratory difficulties from pulmonary edema - resulting in unplanned reintubation. 
  3. Monitored cardiologically - arrythmias from fluid and electrolyte shifts
  4. MI from both the stress of the procedure and effects of aortic clamping and unclamping 

31

Following surgery for AAA - the patient returns to you complaining of impotence. What is your recommendation? 

  1. Erectile dysfunction should be assessed preoperatively
  2. Iatrogenic causes during aortic dissection are due to interruption of the hypogastric circulation or autonomic nerves on the anterior surface of the aorta near the inferior mesenteric artery which course over the aortic bifurcation. 

32

A patient undergoes repair for a ruptured AAA. The patient develops fever and a small amount of bloody diarrhea on the third postoperative day. What is the diagnosis? 

  • This is ischemic injury to the colon
    • Ischemic colitis usually involves the rectosigmoid segment and is due to interruption of a patent inferior mesenteric artery in the setting of compromised blood flow from the superior mesenteric and hypogastric arteries. 

33

What are the clinical signs and symptoms if ischemic colitis? 

  • Postoperative symptoms include:
    • liquid brown or bloody diarrhea
    • abdominal pain
    • tenderness
    • prolonged ileus 
    • increased abdominal distention 
    • signs of sepsis or peritonitis 

34

What investigations would you choose to confirm ischemic colitis? 

  • Immediate sigmoidoscopy is necessary to establish a diagnosis. 
    • The mucosa could appear edematous, hemorrhagic or necrotic 

35

What is your treatment plan for ischemic colitis? 

  • Bowel rest
  • Maintenance of adequate hydration and hematocrit
  • GI tract decompression
  • Antibiotics
  • Frequent reexamination - repeat endoscopy
  • Full thickness involvement requires resection of nonviable bowel and end colostomy 

36

A patient undergoes repair for a ruptured abdominal aortic aneurysm. Two months later, returns with fever and an inflammed femoral incision.  What has happened? 

  • Vascular graft infection - one of the most serious complications of aortic surgery 
    • graft infection most commonly results from contamination by skin flora - most often Staph.epidermidis or S.aureus

37

What are some of the presenting signs of a vascular graft infection?

  • Systemic sepsis
  • Wound abscess
  • Pseudoaneurysm
  • Sinus tract
  • GI hemorrhage
  • Abdominal or back pain
  • CT confirms diagnosis

38

A patient undergoes repair for a ruptured AAA. One year later, the patient returns with an upper GI bleed. What is the likely diagnosis? 

  • Aortoenteric fistula 
    • This lesion develops as a result of erosion of the graft into the third or fourth part of the duodenum

39

How do you confirm a diagnosis of an aortoenteric fistula? 

  • Diagnosis is confirmed by endoscopy, CT of the abdomen or angiography 
  • Treatment requires removal of the graft and repair of GI tract and extra-anatomic bypass. 

40

A 49 year old woman presents with a 6 month history of postprandial abdominal pain, 20 lb weight loss and intermittent diarrhea. On physical examination, multiple abdominal bruits are evident. What is your diagnosis? 

Chronic mesenteric ischemia which is usually secondary to atherosclerotic occlusion of the celia and superior mesenteric arteries. Postprandial pain due to ischemia of the intestines causes fear of food, leading to weight loss. 

41

How would you evaluate a patient with a suspected case of mesenteric ischemia? 

  1. Mesenteric arteriogram to establish diagnosis
    • Then plan revascularization if appropriate