Ir -- Lower Extremities

Front 1

What is the most common cause of arterial occlusion?

Back 1

Thrombosis of an atherosclerocic stenosis

Front 2

1. What is the treatment of unilateral iliac artery occlusion?
2. What is the treatment of atherosclerotic disease of the common femoral artery/SFA?
3. What is an endovascular option for infrapopliteal occlusive disease?

Back 2

1.
- Aortofemoral bypass: >90% patency at 5 years.
- Femorofemoral bypass: option for pts with a normal contralateral iliac artery.
- Endovascular recanalization:
2. Femoral-popliteal bypass graft
3. Endovascular atherectomy using the silver hawk plaque excision device.

Front 3

1. What symptoms are present with SFA occlusion?
2. What is the most common location of stenosis of the SFA?
3. How do you describe stenosis/occlusion of the SFA?

Back 3

1. Calf claudication
2. Adductor (Hunter's) canal
3.
- Evaluate the status of the common femoral artery as this vessel represents the source vessel for a therapeutic bypass graft.
- Point at which the distal circulation reconstitutes. This will determine the distal anastomotic site of the bypass graft.
- Status of the ipsilateral profunda femora artery will often determine the clinical status of the limb since this vessel provides the source of collaterals which reconstitute the distal circulation.

Front 4

1. What are the predictable stages of chronic limb ischemia?
2. What are some important numbers to remember for ABI?
3. What are the etiologies of ulcerating lesions in the foot?

Back 4

1. Claudication --> rest pain --> tissue loss --> gangrene.
Stages beyond claudication are termed limb threatening.
2. An index of 0.3-0.5 indicates severe claudication. An index < 03 indicates rest pain and tissue loss.
3. Ulcerating lesions in the foot may be due to venous or arterial insufficiency. Venous ulcers typically occur in the setting of venous stasis, and are associated with normal arterial pulses, are relatively painless, and heal with elevation and/or compressive measures. Arterial ulcers typically occur at pressure points such as bunion area, are painful, have a necrotic base, and emit no pulse.

The patient lies supine. Take systolic blood pressure in the brachial arteries. Then take systolic blood pressures and doppler waveforms in the proximal thigh, distal thigh, calf, ankles, and big toe. ABI is calculated as a ratio of systolic blood pressure at a particular site to the brachial pressure.

NOTE: sometimes due to calcifications of the arterial walls, the systolic blood pressure may be falsely elevated as it requires a higher pressure to compress the arteries.

Front 5

How does angioplasty of the tibial artery compare to femoral-popliteal or iliac angioplasty?

Back 5

Tibial angioplasty has a lower long term patency rate. However, the patency rates are sufficient to allow for ulcer healing without surgical bypass.

Front 6

1. What is the etiology of popliteal artery entrapment syndrome (PAES)?
2. What are the complications of PAES?
3. What is the treatment of PAES?
4. What is the DDX of narrowing of the popliteal artery?

Back 6

1. PAES may result from
- abnormal course of the popliteal artery
- compression by the medial head of the gastrocnemius muscle

2. PAES is the lower extremity equivalent of arterial thoracic outlet syndrome.
It can be complicated by:
- stenosis and occlusion
- post-stenotic dilatation and aneurysm formation
- distal thromboembolism
- premature atherosclerotic disease
3. Like thoracic outlet syndrome, treatment is surgical decompression. If there is acute ischemia related to thromboembolic disease, the patient may benefit from thrombolysis.
4.
- PAES
- Narrowing due to atherosclerosis
- Occlusion due to thromboembolism
- Thrombosed popliteal aneurysm
- Cystic adventitial disease

Front 7

1. What is the persistent sciatic artery?
2. What is a frequent complication with this arterial variant?

Back 7

1.
- Arterial variant due to persistence of the embryonic sciatic artery (branch of the internal iliac artery).
- Normally, the sciatic artery regresses during development and the femoral artery takes over the blood supply to the lower extremity.
- In this condition, the femoral vessels remain hypoplastic and the arterial supply to the leg is derived from the internal iliac artery.
2.
- The sciatic artery courses posteriorly around the hip and maintains a position similar to the inferior gluteal artery.
- Because of its posterior course, the sciatic artery is at risk for the development of traumatic pseudoaneurysm.

Front 8

1. What is the most common complication of popliteal artery aneurysm?
2. What is associated with popliteal artery aneurysm?

Back 8

1. Distal thromboembolism. Rupture is a much rarer complication.
2. AAA. Therefore, recommend US or cross sectional study for further evaluation.

Front 9

Treatment of DVT

Back 9

- rapid DVT resolution may protect against valvular incompetency and post thrombotic syndrome.
- approach can be from above or below the DVT.
- long infusion times and large doses of TPA are required.
- compression stockings and oral anti-coagulation for 6 months after the procedure.
- complication of severe venous outflow obstruction = phlegmasia cerulea dolens.

Front 10

Popliteal artery occlusion:

Back 10

ATHEROSCLEROSIS:
- MCC of popliteal artery stenosis and occlusion.
EMBOLISM:
- source = cardiac, AAA
- thrombolysis rather than thrombectomy may be attempted if time allows.
TRAUMA:
- occlusion can be seen following blunt and penetrating trauma
- vascular injury is associated with posterior knee disclocation.
THROMBOSED POPLITEAL ARTERY ANEURYSM:
- usually 2/2 atherosclerotic disease. Less common from connective tissue d/o, trauma, vasculitis.
- bilateral in 50-70% of pts; 50% of pts have AAA.
- Pts may present with occlusion of popliteal artery, blue toe syndrome (distal emboli), and rarely rupture.
- TX = surgery; stent grafts in high risk pts.
POPLITEAL ARTERY ENTRAPMENT SYNDROME
- arterial compression due to medial head of gastrocnemius.
- provocative maneurs -- plantar and dorsiflexion of foot.
CYSTIC ADVENTITIAL DISEASE:
- mucoid cysts in the adventitia of popliteal artery leading to compression of the artery.
- MRI = vassel narrowing due to mucinous cyst.
- TX = cyst aspiration (high risk of recurrence; surgery.