Comparative efficacy and safety of intelligent pressure-controlled versus flexible vacuum-assisted ureteral access sheath for 2-4 cm renal calculi.

Background: Retrograde intrarenal surgery (RIRS) is being increasingly used to treat 2-4 cm renal stones, which can be attributed to advances in flexible ureteroscopes and ureteral access sheaths (UASs). Despite the improvement and application of flexible vacuum-assisted (FV) and intelligent pressure-controlled (IPC) UASs, no studies have compared their therapeutic efficacy and safety. Therefore, this study aimed to compare the therapeutic efficacy and safety of IPC-UAS and FV-UAS in RIRS 2-4 cm renal stones.

Methods: We included 96 and 103 patients who underwent IPC-UAS and FV-UAS RIRS, respectively, for 2-4 cm renal stones. Stone-free rate (SFR), operative time, and complications were compared between the two groups.

Results: The immediate SFR was 69.8% and 82.5% in the IPC-UAS and FV-UAS groups, respectively (P<0.05). There were no significant between-group differences in the 1-month SFR (84.4% vs. 84.5%, P>0.05). The IPC-UAS group had a shorter hospital stay (5.2±2.4 vs. 6.2±3.2 days, P=0.018) and lower cost (CNY13014.7±3240.7 vs. CNY14022.5±2301.6, P=0.012) than the FV-UAS group. There were no significant between-group differences in operative time or complications.

Conclusions: Regarding RIRS for 2-4 cm renal stones, the IPC-UAS group can achieve a 1-month SFR similar to that of the FV-UAS group, with shorter hospitalization and lower cost. Additionally, the IPC-UAS is a promising device for efficient and safe RIRS, considering its intelligent pressure regulation. Our findings could inform optimal UAS selection for managing large renal calculi and demonstrate the utility of the novel IPC-UAS in improving outcomes of RIRS for 2-4 cm renal stones.