Significance and management of inflow gradients unexpectedly generated after femorofemoral, femoropopliteal, and femoroinfrapopliteal bypass grafting

Abstract

With multilevel arteriosclerosis, some patients undergoing infrainguinal bypass grafting will develop femoral/brachial pressure gradients only after the bypass is performed. We therefore evaluated arteriographically alternate inflow sites and measured the femoral/brachial pressure gradients before and after placement of 87 femorofemoral and 510 femoropopliteal/infrapopliteal bypasses. No prebypass femoral/brachial pressure gradients were present with and without intraarterial papaverine. However, femoral/brachial pressure gradients ≥15 mm Hg were observed after the bypass placement in 16 femorofemoral patients and 43 femoropopliteal/infrapopliteal patients. Gradients averaged 28 ± 8 (SD) (range, 15 to 50) mm Hg. The post femorofemoral bypass gradients were treated by immediate supplementary inflow extension to the aorta (three patients) or an axillary artery (three patients); by postoperative iliac percutaneous transluminal angioplasty (four patients) or by no treatment (six patients with femoral/brachial pressure gradients of 15 to 35 [23 ± 5] mm Hg). The 43 postfemoropopliteal/infrapopliteal bypass gradients were treated by immediate supplementary inflow extension to the contralateral femoral artery (15 patients), the aorta (8 patients), or an axillary artery (3 patients); by postoperative iliac percutaneous transluminal angioplasty (5 patients) or by no treatment (12 patients with femoral/brachial pressure gradients of 15 to 30 [21 ± 4] mm Hg). No thrombosis occurred in the 10 femorofemoral bypasses with postbypass femoral/brachial pressure gradients that were treated. One of the six femorofemoral patients with untreated gradients required a subsequent aortic extension, and one thrombosed after 2 years. Of the 12 untreated patients with femoropopliteal/infrapopliteal bypasses one graft occluded early, and two late failures occurred 12 and 18 months later. These data underscore the importance of measuring femoral/brachial pressure gradients after placement of bypasses from the femoral artery and show that 10% of femorofemoral and femoropopliteal/infrapopliteal bypasses will produce unanticipated inflow pressure gradients. Strategies for managing such gradients depend on appropriate preoperative arteriographic evaluation and preparation to anticipate this problem. In selected circumstances, inflow gradients up to 35 mm Hg may be accepted without negatively influencing long-term patency of femorofemoral and femoropopliteal/infrapopliteal bypasses.