Increased patency of artificial microvascular grafts using arteriovenous fistula loops: a two-stage procedure for lengthening the pedicle of free-tissue transfer.

Abstract

The effect of a high-flow system on the patency of artificial microvascular grafts (AMG) was investigated using arteriovenous (A-V) fistula loops made of polytetrafluoroethylene (PTFE) in a clinically useful longer length. At a second stage, the A-V loops, matured for 7 days, were used as recipient conduits for free-tissue transfer. The patency rates of 5-cm long PTFE A-V fistula loops were compared with 5-cm and 1-cm long interpositional micrografts in a rat model. The patency rate of the loops at 7 days was 80 percent, compared to 0 percent for both the 5-cm and 1-cm interpositional grafts. A-V fistula loops matured for 7 days in vivo were divided in their midsections and used as arterial and venous conduits (each 2.5 cm long) for free epigastric flaps (3 x 6 cm) raised from the contralateral groin. Sixty-seven percent (8/12) of the free flaps were viable at 7 days. The A-V fistula loop in a high-flow system has a beneficial effect in maintaining patency of AMGs. PTFE fistula loops matured for 7 days can be used as arterial and venous conduits for microsurgical tissue transfer in rats.