Reconstruction of the Urethral Sphincter with Dynamic Graciloplasty in a Male Rabbit Model

Introduction: The use of artificial urinary sphincters can improve urinary incontinence after radical prostatectomies; however, complications can arise. We hypothesized that dynamic graciloplasty improves urethral sphincter reconstruction. Materials and Methods: Models of urethral sphincter muscle reconstruction were developed in 5 adult rabbits by wrapping the gracilis muscle flap around the urethra. Intraurethral pressure was measured in each of the models before reconstruction (control), after reconstruction, and after electrical stimulation of the flap in reconstructed models (stimulated models). Results: The mean maximum urethral closure pressure was significantly greater in the reconstruction model (69.7 (66.5-115.8) mm Hg) than in the control model (39.2 (33.7-49.6) mm Hg). The mean integral of the urethral pressure and urethral length was also significantly greater in the reconstruction model than in the control mod-el. Furthermore, sphincter tightening was enhanced by the electrical stimulation of the flap. Conclusions: Our results support our hypothesis that the functional reconstruction of urethral sphincters using muscle flaps is promising for the treatment of urinary incontinence.