RESUMO
PURPOSE: Traditional ureteral access sheaths rely on tapered dilators and the Dotter principle of axial force to gain access into the ureter. We compared the performance of a novel balloon expandable ureteral access sheath using radial dilatation with that of a conventional ureteral access sheath. MATERIALS AND METHODS: Ten farm pigs underwent randomized placement of the novel sheath in 1 ureter and a conventional ureteral access sheath in the contralateral ureter followed by videotaped ureteroscopy. Acute study end points included maximum and mean force of sheath insertion and removal, saline flow rate and subjective urothelial damage following sheath insertion/inflation. Additionally, blinded reviewers rated urothelial damage on digitally recorded video following sheath removal. Chronic data included gross and histological ureteral analysis at 30 days. RESULTS: The novel ureteral access sheath inserted with less maximum force (0.36 vs 1.48 pounds, p <0.001) and less average force (0.11 vs 0.49 pounds, p = 0.001). The flow rate during 5 minutes was higher in the new sheath (90.0 vs 80.6 cc per minute, p <0.05). Withdrawal forces were not statistically different between the sheaths. The novel sheath also had a lower subjective trauma scale rating (4.2 vs 6.1, p <0.05). Eight blinded reviewers determined that the novel ureteral access sheath resulted in less total urothelial tear length (1.3 vs 2.7 cm, p = 0.03) and less visible ureteral damage in all animals except 1 (p = 0.04). CONCLUSIONS: The novel balloon expandable ureteral access sheath had easier insertion and a better flow rate, and caused less urothelial trauma in this porcine model. This ureteral access sheath offers a promising new option for ureteral access. A randomized clinical trial is in progress to assess the benefits of this new ureteral access sheath.
