Laparoscopic midsagittal hemicystectomy and replacement of bladder wall with small intestinal submucosa and reimplantation of ureter into graft

Background and Purpose: A variety of biodegradable organic materials have b een used for bladder wall replacement. In some instances, partial replaceme nt has been done using laparoscopic reconstructive techniques. However, to date, this activity has been limited to small patches. Herein, we present t he initial experience with laparoscopic sagittal hemicystectomy and the use of laparoscopic reconstructive techniques to replace half of the bladder w ith small-intestinal submucosa (SIS) and to reimplant the ureter into SIS. Materials and Methods: Six female minipigs (20-25 kg) underwent transperito neal laparoscopic sagittal hemicystectomy; the excised bladder wall was rep laced with a 5 x 15-cm patch of SIS (Cook Biotechnology, Spencer, IN). The ipsilateral ureter was reimplanted through a small incision in the graft an d secured with two sutures. Cystoscopy and cystometrograms were performed u nder general anesthesia preoperatively and at 6 and 12 weeks postoperativel y. Tissues were harvested at 12 weeks. Results: The procedure was successful in six animals (left three, right thr ee). During cystoscopy at 12 weeks, the area of the graft was not distingui shable from normal mucosa. Cystometrograms revealed maintenance of volume a nd compliance, with volumes of 338, 343, and 369 mL and intravesical leak-p oint pressures of 37, 59, and 39 cm H2O at 0, 6, and 12 weeks, respectively . Antegrade ureterograms demonstrated extrinsic obstruction, minimal (two), moderate (three), or complete (one), at the ureterovesical junction. The k idney associated with the completely obstructed ureter was grossly hydronep hrotic at sacrifice. Histologically, patchy epithelialization of the graft with a mixture of squamoid and mature transitional-cell epithelium was foun d. Conclusions: Laparoscopic hemicystectomy with replacement of the bladder wa ll and implantation of the ureter into the SIS graft is a feasible procedur e. Clinical application awaits improvements in the method of ureteral reimp lantation and longer follow-up to assess for ingrowth of muscle and nerve f ibers.