Staging arteriovenous fistula loops for lengthening of free-flap pedicles.

The authors investigated the optimal period of maturation following the creation of arteriovenous (AV) loops using polyterafluoroethylene (PTFE) in a white rat model, which were subsequently used to support free-tissue transfer The AV loops in Group 1 (n = 17) were allowed to mature for 3 days prior to creation of the flap, while those from Group 2 (n = 14) were allowed to mature for 5 days Results were compared to those from a previous study in which the authors reported an 80 percent initial patency rate in = 30) anti a 67 percent viability rate, based on 12 patent loops after 7 days In the presen study, patency rates were 59 percent for the 3-day group and 79 percent for the 5-day group, viabilit y rates were 50 and 64 percent respectively. Considering both patent and nonpatent loops, the overall viability rates were 29 and 50 percent respectively Maturation periods longer than 3 days for AV loops constructed from PTFE micrografts were determined to be preferable for subsequent free-tissue transfer.