Use of Free Peritoneal and Bladder Mucosal Grafts as Ureteral Mucosa Substitutes for Management of Avulsion of the Ureteral Mucosa in a Dog Model

Abstract

Avulsion of the ureteral mucosa is one of the most serious complications of ureteroscopy and considered challenging for urologic surgeons. In this study, we developed two novel methods to reconstruct the impaired ureter. After ureteral mucosal avulsion in a canine model, ureteral reconstruction was performed in one of three ways: free tabularized peritoneal grafts (group A, n = 6); bladder mucosal grafts (group B, n = 6); or simple stenting technique (control group [n = 3]). At postoperative week 10, evaluation with intravenous urography (IVU) was followed by harvesting of reconstructed ureter segments for pathologic analysis. IVU showed nonvisualization of the collecting system of the affected side and histologic evaluation showed imperforation or stenosis in all animals in the control group. IVU showed good visualization of the reconstructed ureter without stenosis in group A and in most animals in group B. There was a mild dilation but no obvious stenosis in one animal in group B. Microscopically, all the reconstructed ureteral lumens were uniformly lined with transitional epithelium. Extensive neovascularity was evident in the subepithelial layer with a streaming of fibroblasts toward the neomucosa. Replacing the avulsed mucosa in the injured ureter with tubularized peritoneal free grafts or bladder mucosal grafts may be an optimal method to manage avulsion of the ureteral mucosa.