RESUMEN
From April 21, 1982 to December 31, 1997, we performed 170 infrainguinal bypass procedures using isolated (n = 35) or composite (n = 135) venous allografts preserved at 4 degrees C as a substitute for saphenous autografts in 146 patients. The mean age of the patient population was 74 years. The indication was critical lower limb ischemia in 71% of cases. Seventy-five percent of procedures were below the knee and 26% were infrapopliteal. Mean length and diameter were 19.5 +/- 0.5 cm and 4.8 +/- 0.5 mm, respectively. After December 8, 1993, a reinforcement net was placed over the graft to prevent expansion in 71% of cases. Primary and secondary 5-year patency, calculated according to the Kaplan-Meier method, were 33 +/- 6% and 43 +/- 6%, respectively. Factors correlated with secondary patency were studied using the log-rank test. Previous ipsilateral infrainguinal revascularization was associated with a 40% decrease in secondary patency at 2 years (71% vs. 31%). Patency at 5 years was correlated with the level of anastomosis (47% for low popliteal anastomosis vs. 30% for infrapopliteal anastomosis). The likelihood of stenosis or dilatation of the allograft was 8% and 29.5%, respectively, at 5 years. The 5-year limb salvage and survival rates were 84% and 57%, respectively. The encouraging results of this series suggest that venous allografts provide a useful alternative for infrainguinal bypass when autologous grafts or other more reliable conduits are unavailable.
