INCREASED PATENCY OF ARTIFICIAL MICROVASCULAR GRAFTS USING ARTERIOVENOUS-FISTULA LOOPS - A 2-STAGE PROCEDURE FOR LENGTHENING THE PEDICLE OFFREE-TISSUE TRANSFER

The effect of a high-flow system on the patency of artificial microvas cular grafts (AMG) was investigated using arteriovenous (A-V) fistula loops made of polytetrafluoroethylene (PTFE) in a clinically useful lo nger length. At a second stage, the A-V]oops, matured for 7 days, were used as recipient conduits for free-tissue transfer. The patency rate s 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 a nd 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) o f the free flaps were viable at 7 days. The A-V fistula loop in a high -now system has a beneficial effect in maintaining patency of AMGs. PT FE fistula loops matured for 7 days tan be used as arterial and venous conduits for microsurgical tissue transfer in rats.