Peripheral Arterial Atherosclerosis Obliterans

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Intermittent claudication

• Resting leg pain, ulceration, or gangrene

• Reduced amplitude or absence of peripheral pulses

• Iliofemoral bruits

• Ankle–brachial artery pressure ratio < 0.9

• Cool feet when supine that blanch on elevation and become rubrous and warm when dependent

GENERAL CONSIDERATIONS

• The major cause of peripheral arterial disease in developed countries is atherosclerosis

• Asymptomatic peripheral atherosclerosis is 3 or 4 times more common than symptomatic disease

• Men and women have the same prevalence of this disease

• Acute arterial occlusions are usually caused by embolism from the heart or more proximal vessels

• The blue toe syndrome is caused by microemboli of cholesterol or thrombotic material from more proximal vessels

• It is often difficult to distinguish embolism from thrombosis in situ unless surgery is done and the occluding material is examined histologically

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Intermittent claudication is the hallmark of peripheral arterial disease

  • – Pelvic artery disease results in thigh or buttock claudication

  • – Femoral or popliteal disease results in calf claudication

• Chronic critical leg ischemia can cause persistent rest pain, ulcerations, or gangrene of the foot

PHYSICAL EXAM FINDINGS

• Femoral or iliac bruits

• Weak distal pulses

• Distal extremity ulcerations, especially at pressure points

• Leg elevation results in a pale color

• Sitting after leg raising results in a slow return of color (1 or more minutes), which develops into a red-blue hue

• Decreased nail growth and hair loss in the extremity

• Extremity cool to the touch

• Blue toes

DIFFERENTIAL DIAGNOSIS

• Sciatica from lower back disease

• Arterial embolism

• Erythromelalgia

• Vascular compartment compression syndromes

• Buerger’s disease

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, erythrocyte sedimentation rate, prothrombin time, fibrinogen

• Plasma viscosity

IMAGING STUDIES

• Duplex ultrasound images the vessel and the flow inside it

• Vital capillaroscopy can assess the capillaries in the skin

DIAGNOSTIC PROCEDURES

• Angiography can delineate stenoses

• Intravascular ultrasound can clarify lesion characteristics

• Magnetic resonance angiography can be useful

• Invasive angiography only if surgery or a percutaneous procedure is planned

TREATMENT

CARDIOLOGY REFERRAL

• Suspected coronary artery disease

HOSPITALIZATION CRITERIA

• Threatened limb loss

• Gangrene

• Planned surgery

MEDICATIONS

• Stop smoking

• Exercise training

• Antiplatelet drugs—aspirin 81 mg/day, clopidogrel 75 mg/day PO

• Vasodilators: pentoxifylline 400 mg PO tid

• Prostacyclin analogs

• Anticoagulants in selected cases

THERAPEUTIC PROCEDURES

• Hyperbaric oxygen may help wound healing in chronic limb ischemia

• Angioplasty in selected cases

• Thrombectomy in selected cases