Patency of the primary pedal arch, blood flow through a femoro-tibial graft, and the role of a distal arteriovenous shunt.

In a series of 30 femoro-tibial grafts for limb salvage, blood flow through the graft was compared to patency of the primary pedal arch. Where the primary pedal arch was occluded mean flow was 83 +/- 44 ml/min compared to 152 +/- 51 mls/min when the pedal arch was complete (p less than 0.01). In order to increase blood flow through the graft in patients with an occluded pedal arch, an arteriovenous shunt was constructed at the distal tibial anastomosis. Following this procedure mean flow increased to 236 +/- 92 mls/min (p less than 0.001). The cumulative patency rate in patients who required an arteriovenous shunt was 65% at 6 months, compared to 68% in patients with a complete pedal arch in whom an arteriovenous shunt was not thought necessary. The results show that an arteriovenous shunt may be of value when blood flow through a femoro-tibial graft is limited by occlusive disease in the primary pedal arch.