[Inframalleolar bypass in limb salvage. Late results]

The objective of this retrospective study was to report the long-term results of distal revascularization at the ankle in patients with critical ischemia.

From January 1989 to November 1999, 50 inframalleolar bypasses were performed in 49 patients (35 males and 14 females with a mean age of 75 years [range: 51 to 95 years]). Twenty-five patients (50%) were diabetics. All patients presented with critical ischemia of the lower limb. Distal anastomosis was performed at the retromalleolar posterior tibial artery in 28 cases (56%), pedal artery in 20 cases (40%) and distal fibular artery in two cases (4%). Bypasses were performed using a greater saphenous vein (n = 38), a cryopreserved arterial allograft (n = 9), or a PTFE graft (n = 2). A composite graft with greater saphenous vein and arterial allograft was performed in two cases.

There were two early postoperative deaths. One patient presented a blow-out of the distal anastomosis that required bypass ligation and subsequent leg amputation. Early thrombosis of the graft occurred in four cases, leading to major amputation in three cases. No patients were lost to follow-up and mean follow-up was 26.7 months (range: 1 to 86 months). Graft thrombosis occurred in 15 patients and led to amputation in 6 cases. Bypass graft patency rate was 72% and 61% at 1 year and 3 years, respectively, yielding a 80% limb salvage rate at 3 years. The 3-year actuarial survival rate was 53%.

Inframalleolar bypasses are a valuable tool in patients with critical ischemia. The lower limb salvage rate is satisfactory in this elderly population. Based on this experience, angiography with good run-off and, when necessary, a surgical approach to verify patency of the arteries at the ankle should always be performed before undertaking a major amputation.