Hemodynamics of sequential grafts

Sequential femoropopliteal-tibial grafts have been advocated as a promising treatment for use in patients with severe ischemia of the distal lower extremity. Proponents hypothesize better patency rates due to documented increases in proximal graft flow with the sequential technique. We hypothesized that the effect of the sequential graft was to create competitive collateral flow and that distal graft flow would not be increased with the addition of a sequential anastomosis. Seven adult dogs with chronic occlusions were studied with angiography and underwent sequential iliofemoral bypass grafting. Proximal and distal flows were measured with and without the sequential anastomosis open to flow. Proximal graft flows increased significantly whereas distal flows decreased significantly in all dogs with an open sequential anastomosis. The study suggests that there may be limitations to the use of sequential bypass grafts.