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

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/branchial pressure gradients greater than or equal to 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.(ABSTRACT TRUNCATED AT 250 WORDS)