Reoperation for polytetrafluoroethylene bypass failure: the importance of distal outflow site and operative technique in determining outcome.

Of 724 bypasses with polytetrafluoroethylene grafts performed for critical ischemia during a 6-year period, 165 (23%) failed and necessitated reoperation for continued limb salvage. Forty-three failures occurred in 199 femoral-above-knee-popliteal bypasses (F-AKP), 33 failures in 177 femoral-below-knee-popliteal bypasses (F-BKP), 52 failures in 182 femorodistal bypasses (F-D), 28 failures in 85 axillofemoral bypasses (Ax-F), and nine failures in 81 femorofemoral bypasses (F-F). Our reoperative approach consisted of dissection of the distal anastomosis, longitudinal incision in the hood of the graft directly over the anastomosis, and proximal graft thrombectomy. Intimal hyperplasia was treated by patch angioplasty, proximal or distal progression of atherosclerosis was treated by a graft extension, and thrombectomy alone was performed when no cause of graft failure was identified. More recently, a totally new bypass was constructed in 27 cases of F-BKP or F-D failures. Reoperations featuring graft salvage for failed extra-anatomic and F-AKP bypasses yielded 3-year patency rates from the time of first reoperation of 71% and 52%, respectively, whereas for F-BKP and F-D reoperations, 3-year patency rates were 13% and 15%, respectively, at 3 years. However, totally new grafts to a different outflow artery in these settings had 3-year patency rates of 48% and 39%. These data support the aggressive use of reoperation with graft salvage when F-AKP or extra-anatomic graft failure reproduces critical ischemia. Conversely, a new bypass to a virginal outflow site, preferably with autologous vein, should be performed when a polytetrafluoroethylene F-BKP or F-D bypass fails.