Gracilis muscle neosphincter for treating urinary incontinence

The purpose of this study was to test the anatomical and functional feasibi lity of using a gracilis muscle free flap to create a urinary sphincter. An atomical studies were performed in 12 human cadavers and short-term (n=7) a nd long-term (n=8) functional studies were performed in dogs. In the short- term functional studies, the left gracilis muscle was transferred into the pelvis and wrapped around the urethra and the right gracilis muscle was wra pped around a stent. A cuff electrode was placed on the muscle's nerve pedi cle and used to stimulate the neosphincter while peak pressure, fatigue rat e, and perfusion measurements were performed. In the long-term functional s tudies, intramuscular electrodes were inserted into the neosphincter to sti mulate the flap. The flaps were wrapped around the urethra and dogs were fo llowed for 16 weeks, during which time urodynamic measurements were perform ed. Our anatomical studies demonstrated that the gracilis muscle free flap could be transferred into the pelvis to create a urinary neosphincter. Our short-term functional study demonstrated that gracilis muscle free-flap fun ction and perfusion were not compromised by transfer. In our long-term func tional study, all neosphincters provided bladder outlet resistance pressure s consistent with continence. Our anatomical, short-term, and long-term fun ctional studies indicate that a gracilis muscle free-flap neosphincter is a n effective procedure for treating urinary incontinence. (C) 2001 Wiley-Lis s, Inc.