Efficacy and safety of tip-bendable suction ureteral access sheath-assisted flexible ureteroscopic lithotripsy compared with mini-percutaneous nephrolithotomy for the management of 1-3 cm simple lower calyceal calculi: a prospective randomized controlled trial

Abstract

Objective: To assess the efficacy and safety of flexible ureteroscopic lithotripsy (f-URL) assisted by the tip-bendable suction ureteral access sheath (SUAS) and mini-percutaneous nephrolithotomy (mPCNL) for the treatment of simple lower calyx renal calculi.

Methods: A prospective randomized controlled trial was conducted on 102 patients with simple lower calyx renal calculi (with a diameter of 1 ~ 3 cm) admitted to the Second Hospital of Tianjin Medical University from December 2023 to February 2025. The patients were randomly assigned to the SUAS f-URL group (n = 49) and the mPCNL group (n = 53). The primary endpoint of the study was the immediate stone-free rate (SFR), while the secondary endpoints included operative time, anesthesia time, visual analogue scale (VAS) pain score, estimated blood loss, complication rate, length of hospital stay, hospitalization cost, and the SFR at 30 days postoperatively.

Results: The two groups had comparable baseline characteristics. The SUAS f-URL group demonstrated a similar immediate SFR compared to the mPCNL group (67.35% vs. 66.04%, p = 0.889). Compared to the mPCNL group, the SUAS f-URL group had a shorter anesthesia time (78.08 ± 29.79 vs. 94.62 ± 34.22 min, p = 0.011), a shorter postoperative hospital stay (3.00 [1.50, 3.00] vs. 3.00 [2.00, 5.50] days, p = 0.003), and lower overall costs (3171.21 ± 373.34 vs. 5056.69 ± 358.97 USD, p < 0.001). There were no statistically significant differences between the two groups in terms of postoperative complications, estimated blood loss, pain scores, or SFR at 30 days postoperatively.

Conclusion: Compared to mPCNL, SUAS f-URL achieved a similar SFR while offering advantages such as less anesthesia time, shorter hospitalization, and lower hospitalization costs. Moreover, it did not increase the incidence of perioperative complications such as infection and blood loss. Therefore, SUAS f-URL would be a viable alternative supported by preliminary evidence for the management of 10-30 mm simple lower calyceal renal calculi.

Keywords: Flexible ureteroscopic lithotripsy; Lower renal Calyceal calculi; Percutaneous nephrolithotomy; Tip-bendable Suction ureteral access sheath.