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

Objective: to assess the haemodynamic effect of a free muscle flap on the m idterm success of a pedal bypass. Design: prospective consecutive study. Materials: a pedal bypass (autogenous vein graft) combined with a free musc le flap was performed in 13 patients with critical leg ischaemia. The feedi ng artery of the flap was anastomosed end-to-side to the bypass. Methods: blood flow was measured in the bypass before and after transplanti ng the flap. Doppler was used postoperatively to assess the patency. Results: the bypass and flap pedicle were patent in 11 cases six months pos toperatively, Two grafts were thrombosed and the legs amputated. In the suc cessful group the median (range) blood flow in the bypass was 50 (10-100) m l/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 fl ap 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 fai lure group the free flap received most of the blood supply through the bypa ss. Conclusions: a free muscle flap connected to an infrapopliteal bypass incre ases the distal outflow bed and thus decreases the outflow resistance and i ncreases graft flow.