Acute limb ischaemia — the classification and the revascularisation

The Rutherford classification (I to III):

• I viable — no immediate threat; no sensory/motor loss; arterial and venous Doppler audible. Heparin and workup.
• IIa marginally threatened — salvageable with prompt treatment; minimal sensory loss; no motor. Urgent.
• IIb immediately threatened — salvageable ONLY with immediate revascularisation; sensory + mild motor loss (toe/ankle). Emergency — straight to theatre.
• III irreversible — permanent tissue loss; profound paralysis/anaesthesia. Amputation or palliation.^[3][1]

The revascularisation by the cause:

• The embolic (the atrial fibrillation, the mural thrombus, the aneurysm — the sudden, the white, the no collaterals) → the surgical embolectomy (the Fogarty catheter), the open procedure.
• The thrombotic (the peripheral vascular disease, the native, the graft, the bypass occlusion — the history of claudication, the collaterals) → the catheter-directed thrombolysis or the percutaneous mechanical thrombectomy, with the angioplasty or the stent.^[1]

The principles: The immediate vascular referral and the IV unfractionated heparin for all; the revascularisation before the muscle necrosis is complete; the prophylactic fasciotomy for the prolonged ischaemia; the anticoagulation of the embolic source; and the monitoring of the reperfusion complications (the hyperkalaemia, the myoglobinuria, the compartment syndrome).^[1][2]