Impact of Ureteral Access Sheath on Stone Clearance, Efficiency, and Complications in Retrograde Intrarenal Surgery: A Retrospective Comparative Study

Objective: To compare stone-free rates (SFR), operative times, and complication profiles in retrograde intrarenal surgery (RIRS) procedures performed with and without ureteral access sheath (UAS) use. Materials and Methods: A total of 420 patients undergoing RIRS for renal or proximal ureteral stones (≤2 cm) between January 2020 and May 2024 were retrospectively analyzed. Patients were divided into two groups based on intraoperative use of UAS. Demographics, stone characteristics, operative parameters, and postoperative complications were compared. Results: SFR was significantly higher in the UAS group (96.3% vs. 85.2%, p=0.008). Operative time was shorter in the UAS group (29.8 ± 9.6 vs. 46.5 ± 10.2 min, p=0.007), which may be attributed to enhanced irrigation and improved endoscopic visualization associated with sheath use. Infectious complications—including postoperative fever and sepsis—were less frequent in the UAS group, which may reflect improved drainage dynamics and reduced intrarenal pressure (IRP) (p<0.05). UAS use was also associated with fewer cases of renal pelvic perforation and postoperative renal colic. However, UAS placement resulted in longer fluoroscopy exposure (9.17 vs. 3.71 seconds, p=0.002), higher rates of mucosal injury, bleeding, and ureteral perforation, and a significantly increased need for preoperative stenting (21.2% vs. 5.4%, p=0.001), likely due to the sheath’s larger caliber (10–12 Fr vs. 7.5 Fr for flexible ureteroscopy (fURS). Conclusion: UAS use in RIRS enhances stone clearance, shortens operative time, and lowers infectious complication rates by ensuring efficient drainage and lower IRP. However, its associated risks—especially ureteral trauma and radiation exposure—warrant careful patient selection. UAS should be considered selectively, particularly for large-volume or lower pole stones, based on a case-by-case risk-benefit assessment by the surgeon.