Acute Limb Ischemia With a Motor Deficit
A 76-year-old man with atrial fibrillation, not currently anticoagulated, presents 7 hours after sudden onset of right leg pain. The right foot is pale and mottled below the knee, with absent dorsalis pedis and posterior tibial signals, mild weakness of toe extension, and diminished light touch. The left leg is normal. He is in sinus rhythm with a heart rate of 96/min; creatinine is 1.6 mg/dL. Duplex shows occlusion of the right superficial femoral artery. He is on apixaban but missed doses for 3 days. The vascular suite and operating room are both available.
1. What is the clinical classification and why does it mandate immediate operative revascularization rather than catheter-directed thrombolysis?
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He has Rutherford class IIb acute limb ischemia: sensory loss and mild motor deficit with absent Doppler signals. This is a threatened limb and requires immediate revascularization, usually open embolectomy or bypass. Catheter-directed thrombolysis is too slow and is relatively contraindicated with a motor deficit because time-dependent nerve and muscle injury is already occurring. Give systemic heparin, optimize electrolytes, and proceed to the operating room. The 7-hour window and motor deficit make immediate surgery the priority; the vascular suite can be used intraoperatively for completion angiography. Anticoagulation for atrial fibrillation should be addressed after hemorrhage control.
2. At operation, a balloon embolectomy retrieves thrombus, but there is no backbleeding and the foot remains mottled. What are your next steps?
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Lack of backbleeding suggests distal thromboembolism or underlying arterial disease. Obtain an intraoperative angiogram to define the anatomy. If there is distal thrombus, use a Fogarty catheter or intraoperative thrombolysis; if there is a focal stenosis, proceed to bypass. Check compartment pressures because reperfusion will worsen swelling. A completion angiogram is mandatory before leaving the room. If the foot remains mottled despite a patent artery, consider vasospasm, embolization, or compartment syndrome. Do not close a tense leg.
3. Postoperatively he develops tense swelling and pain with a compartment pressure of 38 mmHg. How do you manage, and what anticoagulation plan do you recommend?
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A compartment pressure of 38 mmHg with pain and tense swelling is acute compartment syndrome; perform a four-compartment fasciotomy without delay. Continue heparin intraoperatively and transition to long-term anticoagulation for atrial fibrillation once hemostasis is secure. A direct oral anticoagulant can be restarted when bleeding risk is acceptable, but warfarin is also reasonable. Monitor renal function and creatine kinase for rhabdomyolysis, and watch for reperfusion arrhythmias. Plan delayed skin grafting or closure. Missing compartment syndrome can lead to amputation.