The Safety and Efficacy of Sotn ureteroscopy for Renal and Upper Ureteral Calculi: A Prospective Multicenter Randomized Controlled Trial

Abstract

Purpose Sotn ureteroscopy is a new lithotripsy procedure developed on the basis of ureteroscopy and includes a rigid ureteral access sheath, standard mirror, lithotripsy mirror, and Sotn perfusion aspirator. Thus, we performed a prospective multicenter randomized controlled trial comparing the safety and efficacy of Sotn ureteroscopy in the treatment of renal and upper ureteral calculi. Materials and Methods 224 patients with renal and upper ureteral calculi were randomly divided equally into study and control groups from March 2018 to March 2022. All of the patients were approved by the hospital ethics committee (proof number: ZF-2018-164-01 and ZF-2018-165-01) of the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and month after treatment and operation duration. The secondary outcome was postoperative complication rate. Results In total, for upper ureteral calculi, the SFR of 1 day after operation of the Sotn ureteroscopy group was significantly higher than the rigid ureteroscopy group (83.6% vs. 60%, P = 0.006). Moreover, operative time (33.7 ± 1.80 vs. 52.9 ± 2.73 min, P < 0.005) of the Sotn ureteroscopy group was significantly lower than the rigid ureteroscopy group. Additionally, the SFR of 1 day after operation and operative time for the study group (Sotn ureteroscopy combined with flexible ureteroscopy) and the control group (flexible ureteroscopy alone) were 63.2% and 36.8% (P = 0.005), 65.6 ± 4.06 and 80.3 ± 4.91 (P = 0.023), respectively. However, there were no significant differences in the SFR of 1 month after operation, success rate of ureteral access sheath placement, and postoperative complications between the two groups (P > 0.05). In subgroups with stone diameters ≥ 1.5 cm and stone CT values ≥ 1,000 Hounsfield units, Sotn ureteroscopy showed more advantages in terms of the SFR of 1 day after operation. Importantly, complications such as ureteral injury, sepsis, fever and severe haematuria were not statistically different between the two groups (P > 0.05). Conclusions For renal and upper ureteral calculi, Sotn ureteroscopy has the advantage of a higher SFR of 1 day after the operation, a shorter operative time and low complication rates, suggesting that the Sotn ureteroscopy may have further potential applications in clinics.