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For further information, see CMDT Part 12-04: Acute Arterial Occlusion of a Limb

Key Features

Essentials of Diagnosis

  • Sudden pain in an extremity with absent extremity pulses

  • Neurologic dysfunction (eg, numbness, weakness, or complete paralysis)

  • Loss of light touch sensation requires revascularization within 3 hours for limb viability

General Considerations

  • May be due to an embolus or to thrombosis of a diseased atherosclerotic segment

  • Destinations of emboli from the heart

    • Lower extremities (50%)

    • Cerebrovascular circulation (20%)

    • Upper extremities and mesenteric and renal circulation (30%)

  • Emboli from arterial sources, such as arterial ulcerations or calcified excrescences, are usually small and go to the distal arterial tree (toes)

  • Causes of the thrombus

    • Atrial fibrillation (most common)

    • Valvular disease

    • Thrombus formation on the ventricular surface of a large anterior myocardial infarct

  • Patients with primary thrombosis have a history of claudication

  • If stenosis developed over time, collateral blood vessels develop and resulting occlusion may only cause a minimal increase in symptoms

Clinical Findings

Symptoms and Signs

  • Sudden onset of extremity pain, with loss or reduction in pulses

  • Neurologic dysfunction (eg, numbness or paralysis)

  • With popliteal occlusion, only the foot may be affected

  • With proximal occlusions, the whole leg may be affected

  • Signs of severe arterial ischemia

    • Pallor

    • Coolness of the extremity

    • Mottling

Differential Diagnosis

  • Deep venous thrombosis

  • Cerebrovascular accident


Laboratory Findings

  • Blood work may show myoglobin and a metabolic acidosis

Imaging Studies

  • May be helpful in expediting revascularization procedure by

    • Identifying exact areas of occlusion

    • Delineating distal vessel patency

  • May show an abrupt cutoff of contrast with embolic occlusion

  • Doppler examination of the distal vessels demonstrates little or no flow

  • When possible, should be done in the operating room because obtaining angiography, MRA, or CTA may delay revascularization and jeopardize the viability of the extremity

  • However, in cases with only modest symptoms and where light touch of the extremity is maintained, imaging may be helpful in planning the revascularization procedure

Diagnostic Procedures

  • Doppler examination shows little or no flow in the distal vessels



  • Unfractionated heparin

    • Start as soon as the diagnosis is made

    • Dose: 5000–10,000 units intravenously followed by a heparin infusion to maintain the aPTT in therapeutic range (60–85 seconds)

    • Helps prevent propagation of the clot

    • May also help relieve associated spasm of the vessels


  • General anesthesia is usually indicated

  • Local anesthesia may be used in extremely high-risk patients if the exploration is limited to the common femoral artery

  • Revascularization

    • Required in all cases ...

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