Active-Locking Deflectable Versus Passively Deflectable Suction Ureteral Access Sheath During Flexible Ureteroscopy for Lower Calyceal Stones: A Retrospective Comparative Study

<title>Abstract</title> <p>Purpose To evaluate whether flexible ureteroscopy assisted by an active-locking deflectable suction ureteral access sheath (ALD-SUAS), which allows operator-controlled distal deflection and angle locking, improves operative performance compared with a passively deflectable suction ureteral access sheath (PD-SUAS) for lower calyceal stones. Methods Clinical data from 109 patients treated between January 2025 and March 2026 were retrospectively reviewed. Patients were divided into a PD-SUAS group (n = 53) and an ALD-SUAS group (n = 56). Baseline characteristics, perioperative outcomes, stone-free rates, postoperative infection-related indicators, maneuverability, and visual clarity were compared. Multivariable regression models were used to evaluate operative time and stone-free outcomes. Results Baseline characteristics were comparable between groups. Compared with PD-SUAS, ALD-SUAS was associated with shorter operative time (54.30 ± 13.62 vs. 61.30 ± 14.64 min, P = 0.011), lower basket use (12.5% vs. 39.6%, P = 0.001), and higher immediate, postoperative day 1, and 4-week stone-free rates (all P &lt; 0.05). Postoperative fever and inflammatory markers did not differ significantly. Maneuverability and visual clarity scores were better with ALD-SUAS. Multivariable analysis showed that ALD-SUAS remained associated with shorter operative time (β = -6.446, P = 0.030) and higher postoperative day 1 stone-free success (OR = 5.307, P = 0.003), whereas 4-week stone-free success showed a non-significant increasing trend. Conclusion ALD-SUAS-assisted flexible ureteroscopy may improve operative efficiency and early stone clearance without increasing postoperative infection-related risk. Prospective studies are warranted.</p>