Popliteal-to-distal bypass: identifying risk factors associated with limb loss and graft failure

Modern therapy, including endoluminal procedures and improved medical management, still yield less than desired results for tibial vessel occlusive disease. Despite the recent focus on these newer interventions, few modern series have evaluated the efficacy of popliteal-to-distal bypass procedures. The authors aimed to determine the efficacy of popliteal-distal bypass and to identify adverse prognostic factors for ultimate limb salvage. Eighty-seven patients (54 men; average age: 63 years) underwent 92 popliteal-distal bypasses. Duplex ultrasound was utilized to assess patency of all grafts. Data were analyzed by life-table analysis to determine patency rates at postoperative intervals. Median patient follow-up was 2.4 years. Major indications for bypass included chronic limb ischemia (86%) and disabling claudication (8%); 62% of the limbs were considered threatened, and 74% of the proximal anastomoses were above-knee. All procedures were technically successful. There were no perioperative (< 30 days) deaths, and 86% of patients were alive at 5 years. Cumulative patency rates were 74% at 6 months, 70% at 2 years, and 63% at 5 years. Limb salvage rates closely paralleled patency rates. At 5 years, 62% of the affected limbs were intact; 72% of the limbs lost were associated with early (< 180 days) bypass failures. Predictors of limb loss included early graft failure (84 days vs 1,288 days, p < 0.0001), younger age (57 years vs 64 years, p = 0.039), history of previous ipsilateral vascular procedures (50% vs 21%, p = 0.03), heavy (> 1 ppd) tobacco use (p = 0.001), and a thrombosed femoral-popliteal bypass at presentation (p = 0.002). When successful, popliteal-distal bypass is associated with excellent long-term patency and limb salvage rates. Early failures are often associated with limb loss. Heavy tobacco use, younger age, early graft failures, repeat revascularization, and presentation with a thrombosed femoral-popliteal graft are associated with limb loss.