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Updated: Jan 20, 2026

A Murine Model of Irreversible and Reversible Unilateral Ureteric Obstruction
Published on: December 20, 2014
Is it safe to use a ureteral access sheath in an unstented ureter?
Asaf Shvero1, Haim Herzberg2, Dorit Zilberman3
1Department of Urology, The "Chaim Sheba" Medical Center, Ramat-Gan, Israel. Affiliated to Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel. asaf.shvero@sheba.health.gov.il.
Background:
The aim of this study was to examine ureteral stricture rate after the use of UAS in an unstented ureter and compare complications of smaller vs. larger-caliber UAS.
Methods:
We conducted a retrospective analysis of consecutive RIRS for renal stones, with the use of UAS in unstented ureters. We excluded cases with previous ureteroscopies, who carried ureteral stent or nephrostomy, had impacted stones, underwent radiation treatment, or had urinary tract malignancies. The primary outcome was formation of ureteral strictures diagnosed by hydronephrosis in ultrasound test and late secretion in dynamic renal scan. Secondary outcome was stone-free-rate (SFR) and complications. In addition, we compared safety and efficacy of smaller (9.5/11.5Fr) vs. larger-caliber (12/14Fr) UAS.
Results:
The cohort included 165 patients with a median follow-up time of 115 days. There was no case of ureteral stricture formation after the use us UAS, despite using a larger-caliber UAS in nearly half the cases. Larger-caliber UAS was not associated with more complications compared to the smaller-caliber one (p = 0.780). SFR was non-significantly higher in the larger-caliber UAS group (p = 0.056), despite having a larger stone burden, and only stone number was associated with SFR (p = 0.003).
Conclusions:
These data suggest that the use of UAS during RIRS in an unstented ureter is safe and does not involve ureteral stricture formation after one procedure. Furthermore, the use of wider sheaths was not found to be associated with higher complications rate.
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