Occlusive or inflammatory disease that develops within the peripheral arteries, veins, or lymphatics.
ARTERIOSCLEROSIS OF PERIPHERAL ARTERIES
Intermittent claudication is muscular cramping with exercise; quickly relieved by rest. Pain in buttocks and thighs suggests aortoiliac disease; calf muscle pain implies femoral or popliteal artery disease. More advanced arteriosclerotic obstruction results in pain at rest; painful ulcers of the feet (sometimes painless in diabetics) may result.
Decreased peripheral pulses (ankle:brachial index <1.0; <0.5 with severe ischemia), blanching of affected limb with elevation, dependent rubor (redness). Ischemic ulcers or gangrene of toes may be present.
Segmental pressure measurements and Doppler ultrasound of peripheral pulses before and during exercise localizes stenoses; magnetic resonance angiography, computed tomographic angiography (CTA), or conventional arteriography is performed if mechanical revascularization (surgical or percutaneous) is planned.
Most pts can be managed medically with daily exercise program, careful foot care (especially in diabetics), treatment of hypercholesterolemia, and local debridement of ulcerations. Abstinence from cigarettes is mandatory. Antiplatelet therapy is indicated to reduce future cardiovascular events. Some, but not all, pts note symptomatic improvement with drug therapy (cilostazol or pentoxifylline). Pts with severe claudication, rest pain, or gangrene are candidates for revascularization (arterial reconstructive surgery or percutaneous transluminal angioplasty/stent placement).
OTHER CONDITIONS THAT IMPAIR PERIPHERAL ARTERIAL FLOW
Results from thrombus or vegetation within the heart or aorta, or paradoxically from a venous thrombus through a right-to-left intracardiac shunt.
Sudden pain or numbness in an extremity in the absence of previous history of claudication.
Absent pulse, pallor, and decreased temperature of limb distal to the occlusion. Lesion is identified by angiography.
TREATMENT Arterial Embolism
IV heparin is administered to prevent propagation of clot. For acute severe ischemia, immediate endovascular or surgical embolectomy is indicated. Thrombolytic therapy (e.g., tissue plasminogen activator, reteplase, or tenecteplase) may be effective for thrombus within atherosclerotic vessel or arterial bypass graft.
A subset of acute arterial occlusion due to embolization of fibrin, platelets, and cholesterol debris from more proximal atheromas or aneurysm; typically occurs after intraarterial instrumentation. Depending on location, may lead to stroke, renal insufficiency, or pain and tenderness in embolized tissue. Atheroembolism to lower extremities results in blue toe syndrome, which can progress to necrosis and gangrene. Treatment is supportive; for recurrent episodes, surgical intervention in the proximal atherosclerotic vessel or aneurysm may be required.
Manifest by Raynaud's phenomenon in which cold exposure results in triphasic color response: blanching of the fingers, followed by cyanosis, then rubor. Usually a benign disorder. However, suspect an underlying disease (Table 135-1) if tissue necrosis occurs, if disease is unilateral, or if it develops after age 50.