Experimental Study On The Urethral Reconstruction Using Peritoneum

Urethral reconstruction becomes significant while defects in the male urethra, which were caused by traumatic injures, excisions for malignant tumors or surgical operations for congenital malformations, are too large to anastomose native urethra end-to-end. But no organs and tissues available have the same function and anatomy with urethra. So exploring suitable materials as substitutes for urethra has been regarded as an important task. A variety of tissues including skin graft, skin flap, bladder or buccal mucosa have been used in urinary tract replacement. Optimal results in peritoneal tube grafts urethroplasty have been reported. Every method applied in humans has advantages and disadvantages. Through a series of experimental studies, We attempt to research for the histological changes of tubularized peritoneal free grafts placed subcutaneously and mesothelial cells in the same situation as urothelium, and the possibility of tubularized peritoneal free grafts used for urethral reconstruction in urethroplasty or phalloplasty.Rabbits were chosen as our experimental models and experiments were carried out as followed:â‘ Tubularized peritoneal free grafts with mesothelial surface inward were placed in the rabbit subcutaneously, the macroscopic changes of tube architecture and the histological changes of peritoneum were observed. â‘¡Peritoneal tube grafts were bridgedurethra defects, observations above-mentioned were made as well as the difference between peritoneum and skin graft for urethral reconstruction. â‘¢A superficial epigastric fasciovascular pedicle flap for phalloplasty was harvested and tubed over the peritoneal tube, which was anastomosed with native urethra stump. The gross growth of the reconstructed urethra and the histological changes of serous membrane were observed.Results were gained as followed: â‘ Macroscopic examinations of the subcutaneously embedded peritoneal graft revealed a tube architecture prefabricated. And the result has nothing to do with the stent inside. Histological examinations showed that mesothelial cells retained normal structures. â‘¡Peritoneal tube grafts in the urinary tract survived well without obvious strictures and occlusions. The peritoneal mesothelium, which was replaced with urothelium, underwent a metaplastic process and/or the ingrowth of urothelium from the surrounding urethra. The effect of peritoneum for urethral repair seemed somewhat better than that of skin graft. â‘¢Peritoneal tube grafts ,which were protested from drought ,were tubed by the superficial epigastric fasciovascular pedicle flap and also survived well without voiding difficulty and obvious strictures. The conversion of mesothelium into urothelium also occurred.Our study confirms that peritoneal grafts implanted within the softtissues can form and retain the tube architecture. Peritoneum has the capability for urethral repair, as results of which may be inclined to survival condition. It is possible to use peritoneum as urethral substitutes in phalloplasty.