Ureteral anastomosis with a polyimide stent in rat kidney transplantation

Background: Complications associated with ureteral anastomosis in kidney transplantation are highly prevalent, despite the development of various types of stents. The current stent materials and placement methods have several limitations. This study attempts to provide an alternative by investigating ureteral anastomosis with a polyimide stent and a modified placement method in a rat model of kidney transplantation. Methods: Sprague-Dawley rats were randomly divided into Group I: sham operation, Group II: autologous ureteral anastomosis, and Group III: isogenic kidney transplantation with ureteral anastomosis. For the anastomosis, a polyimide stent with a previously placed 11-0 silk was inserted into the ureter. The stent and ureter were fixed with 11-0 silk sutures. The kidney weight and serum creatinine were recorded. The ureteral and renal sections were taken for histological analysis. Results: None of the stents had migrated. Urethral patency was achieved. Further, there were no evident histological changes in the anastomosed ureters. The serum creatinine level in group III was significantly higher than the other two groups, but there was no significant difference in kidney weight among the groups at postoperative week 12. Finally, the histological structure of kidneys in groups II and III only showed minor changes. Conclusions: The current anastomosis method with polyimide stent causes minimal damage to the ureteral walls and minimizes the possibility of stent migration. Therefore, this method of ureteral anastomosis with the polyimide stent should be explored for its potential benefits in more animal kidney transplantation models, thus providing an alternative for the clinical setting.