Blood flow in a pedal bypass combined with a free muscle flap

Abstract

Objective: to assess the haemodynamic effect of a free muscle flap on the midterm success of a pedal bypass. Design: prospective consecutive study. Materials: a pedal bypass (autogenous vein graft) combined with a free muscle flap was performed in 13 patients with critical leg ischaemia. The feeding artery of the flap was anastomosed end-to-side to the bypass. Methods: blood flow was measured in the bypass before and after transplanting the flap. Doppler was used postoperatively to assess the patency. Results: the bypass and flap pedicle were patent in 11 cases six months postoperatively. Two grafts were thrombosed and the legs amputated. In the successful group the median (range) blood flow in the bypass was 50 (10-100) ml/min. It increased (p<0.05) after transplantation to 64 (20-113) ml/min, being 44 (14-97) ml/min distributed to the foot. Blood flow through the flap was 20 (6-37) ml/min. The two failing grafts had a flow of 30 and 51 ml/min before and 48 and 52 ml/min after transplantation, respectively. Blood flow through the flap was 47 ml/min and 36 ml/min, respectively. In the failure group the free flap received most of the blood supply through the bypass. Conclusions: a free muscle flap connected to an infrapopliteal bypass increases the distal outflow bed and thus decreases the outflow resistance and increases graft flow.