Duration of Ureteral Stenting Following Ureteroscopic Perforation in a Porcine Model

Ureteroscopic ureteral perforations have been reported in up to 6% of cases, with recent studies suggesting a decline to less than 2%. Ureteroscopic perforations are managed with prolonged ureteral stenting of up to 6 weeks based on historical data. We sought to evaluate the time of urothelial healing and duration of ureteral stenting following a ureteroscopic perforation in a porcine model. Part A: Ureteral perforation using a semirigid ureteroscope was performed in 37 ureters. The ureters were stented using 4.7F × 22 cm stents for 3, 7, 10, or 14 days, and retrograde pyelograms performed after stent removal. Injured ureteral segments were collected for histologic evaluation. Part B: 8 ureters had endoscopic perforation and stenting for 7 days and then survived for 4 weeks for evaluation of urinary extravasation or hydronephrosis and histologic evaluation. Part A: At 3 days of ureteral stenting, there was urinary extravasation on retrograde pyelograms and gross defect in all ureters; average creatinine increased (1.55-1.75 mg/dL). Starting at 7 days, no evidence of gross urothelial defects or extravasation, and average creatinine was stable. Histologic evaluation revealed urothelial healing by 7 days with ongoing tissue healing. Granulation tissue predominated in early phase of healing. Part B: With only 7 days of ureteral stenting, no extravasation or hydronephrosis developed a month after stent removal. Following ureteroscopic ureteral perforation in a porcine model, the urothelium is functionally intact with 7 days of stenting. These results are sustained without complications for at least 4 weeks after stent removal. While further studies are warranted, these results challenge the current practice of maintaining ureteral stenting for several weeks following ureteral perforation during ureteroscopy.