Occlusive Disease: Femoral & Popliteal Arteries

Essentials of Diagnosis

• Cramping pain or tiredness in the calf with exercise

• Reduced popliteal and pedal pulses

• Foot pain at rest, relieved by dependency

• Foot gangrene or ischemic ulcers

General Considerations

• The superficial femoral artery is the peripheral artery most commonly occluded by atherosclerosis

• The disease frequently occurs where the superficial femoral artery passes through the abductor magnus tendon in the distal thigh (Hunter canal)

• The common femoral artery and the popliteal artery are less commonly diseased, but lesions in these vessels are debilitating, resulting in short-distance claudication

Demographics

• Atherosclerosis of the femoral-popliteal segment usually

  • Occurs about a decade after the development of aortoiliac disease

  • Has an even distribution between males and females

  • Affects black and Hispanic patients commonly

Symptoms and Signs

• Intermittent claudication is confined to the calf

• Claudication at about 2–4 blocks when superficial femoral artery is occluded at the abductor canal and good collateral vessels are maintained from profunda femoris

• Concomitant disease of the profunda femoris or the popliteal artery may trigger symptoms at much shorter distances

• Dependent rubor of the foot with blanching on elevation may be present with short-distance claudication

• Chronic low blood flow states cause atrophic changes in the lower leg and foot with

  • Loss of hair

  • Thinning of the skin and subcutaneous tissues

  • Disuse atrophy of the muscles

• With segmental occlusive disease of the superficial femoral artery, the common femoral pulsation is normal, but the popliteal and pedal pulses are reduced

• Popliteal and pedal pulses are reduced

Differential Diagnosis

• Occlusive disease of the iliac arteries

• Lumbar spinal stenosis

Imaging Studies

• Duplex ultrasonography, CT angiography, or magnetic resonance angiography

  • All adequately show the anatomic location of the obstructive lesions

  • These studies are only done if revascularization is planned

Diagnostic Procedures

• The ankle-brachial index (ABI)

  • Values < 0.9 are diagnostic of PAD

  • Levels below 0.4 suggest chronic limb-threatening ischemia

  • Readings depend on arterial compression

  • Can be misleading since the vessels may be calcified in diabetes mellitus, chronic kidney disease, and the elderly

• The toe brachial index (TBI)

  • Usually reliable; done in those cases where vessels may be calcified

  • Value < 0.7 considered diagnostic of PAD

• Pulse volume recordings with cuffs placed at the high thigh, mid thigh, calf, and ankle will delineate the levels of obstruction with reduced pressures and blunted wave-forms

• Conservative management

  • Cornerstone of therapy

  • Includes risk factor reduction, medical optimization (with high-dose statin), and exercise treatment

  • Cilostazol, 100 mg orally twice daily, may improve intermittent claudication symptoms

Surgery

• Indications

  • Claudication that is progressive, incapacitating or interferes significantly with essential daily activities

  • Presence of ischemic rest pain

  • Ischemic ulcers threaten the foot

• Femoral-popliteal bypass with autologous saphenous vein is most effective and durable treatment for lesions of the superficial femoral artery

• Synthetic material, polytetrafluoroethylene (PTFE) can be used but these grafts do not have the durability of vein bypass

• Removal of the atherosclerotic plaque is now limited to the lesions of the common femoral and profunda femoris artery where bypass grafts and endovascular techniques have no role

• Endovascular techniques such as angioplasty and stenting

  • May be effective for lesions of the superficial femoral artery

  • These techniques have lower morbidity than bypass but also have a lower rate of success and durability

  • Most effective for lesions that are < 10 cm long and in patients who are undergoing aggressive risk factor modification

  • Paclitaxel-eluting stents or paclitaxel-coated balloons

    • Offer modest improvement over bare metal stents and non-coated balloons

    • Meta-analyses of clinical trial data have shown increased mortality 3–5 years after treatment with paclitaxel devices

    • Although they remain on the market, the US FDA has recommended judicious use of the devices

  • However, the success of local drug delivery in peripheral arteries is not as robust as that in the coronary arteries

Follow-Up

• Ultrasound surveillance after all interventions so that recurrent narrowing can be treated promptly

Complications

• Wound infection or seroma can occur in as many as 10–15% of cases

• Myocardial infarction rates after open surgery are 5–10%, with a 1–4% mortality

• Complication rates of endovascular therapy are 1–5%

Prognosis

• Excellent for motivated patients with isolated superficial femoral artery disease

• Patency rate of bypass grafts of the femoral artery, superficial femoral artery, and popliteal artery is 65–70% at 3 years

• Patency rate of angioplasty is < 50% at 3 years

• 5-year mortality among patients with lower extremity disease associated with coronary disease is about 50%

• The 1-year patency rate for

  • Balloon angioplasty: 50%

  • Drug-coated balloons: 70%

  • Stents: 80%

• By 3 years, the patency rates are significantly worse for all three techniques and reintervention for restenosis is common

• Because of the extensive atherosclerotic disease, including associated coronary lesions, 5-year survival with lower extremity PAD is 70% and decreases to 50% when there is involvement of the tibial arteries

• However, with aggressive risk factor modification, substantial improvement in longevity has been reported

When to Refer

• Patients with progressive symptoms, short distance claudication, rest pain, or any ulceration should be referred to a peripheral vascular specialist