Presentation Authors: Amy Reed*, Christopher Allam, San Antonio, TX
Introduction: Ureteral injuries during ureteroscopy have been reported in up to 46% of cases, including 13% involving the muscularis layer and 4% being ureteral perforations. Endoscopic injuries are commonly managed with prolonged ureteral stenting for up to 6 weeks based on historical data. We sought to evaluate the time to urothelial healing after endoscopic ureteral perforation in a porcine model.
Methods: Endoscopic bilateral ureteral perforation using a semirigid ureteroscope was performed in 18 pigs (35 ureters). The ureters were stented using 4.7Fr by 22cm ureteral stents. The stents were maintained for 3, 7, 10 or 14 days and retrograde pyelograms performed after stent removal. After the animals were sacrificed, the ureters were collected for microscopic evaluation of the ureteral perforation site.
Results: At 3 days, there was urinary extravasation on retrograde pyelograms and there was a gross ureteral defect in all 8 ureters. Starting at 7 days, there was no evidence of urinary extravasation on retrograde pyelograms or gross urothelial defect. At three days, the average creatinine increased (1.55 to 1.75mg/dL) and after 7 days, the average creatine decreased (1.42 to 1.27mg/dL). Microscopic evaluation revealed intact urothelium by 7 days with ongoing healing of various degrees within the lamina propria and muscularis layers. Granulation tissue predominated in the early phase of healing within all ureters.
Conclusions: Following endoscopic ureteral perforation in the porcine model, the urothelium is microscopically functionally intact and no extravasation on retrograde pyelogram after 7 days. While it is known that there is ongoing lamina propria and muscular regeneration that continues for several weeks, the degree of urothelial healing after 7 days may be a clinically sufficient duration of ureteral stenting following ureteral perforation during ureteroscopy. Further studies are warranted, but these results challenge the current practice of maintaining a ureteral stent for up to 6 weeks.