Study on the Efficacy and Safety of intelligently Pressure-Controlled, Flexible Negative Pressure Suction Ureteroscopy Lithotripsy Compared with Traditional flexible Ureteroscopy Lithotripsy for the Treatment of 1.0-2.5 cm Renal Stones: A Single-Center Randomized Controlled Trial

Purpose Comparative analysis of the efficacy and safety of intelligent pressure-controlled, flexible negative-pressure suction ureteroscopic lithotripsy (IFANS f-URS)versus traditional flexible ureteroscopic lithotripsy (f-URS)for 1.0–2.5 cm renal stones. Methods A total of 284 patients with 1.0–2.5 cm renal stones were prospectively enrolled between December 2023 and May 2025 at the Department of Urology, Baoshan Second People’s Hospital, China. Patients were randomly assigned in a 1:1 ratio to Group IFANS f-URS or Group f-URS. Surgical duration, lithotripsy time, operative success rate, immediate postoperative stone-free rate (SFR), 3-month postoperative SFR, and incidence of postoperative complications were compared between the two groups. Results No statistically significant differences were observed between the two groups in demographic characteristics, stone size, operative success rate, or stone-free rate (SFR) at 1 month postoperatively.However, the IFANS f-URS group showed significantly better outcomes than the conventional f-URS group in terms of immediate postoperative SFR (136/140, 97.14% vs 121/140, 86.43%; RD 10.71%; 95% CI 4.64%–17.72%), 1-month postoperative SFR (140/140, 100% vs 137/140, 97.86%; RD 2.15%; 95% CI -0.54%–6.15%), and shorter operative duration, with statistically significant differences (P < 0.05).Regarding postoperative complications, the infection rate (fever > 38.0°C) was significantly lower in the IFANS f-URS group compared with the conventional f-URS group (14/140, 10% vs 4/140, 2.86%; P = 0.028).Among them, 8 patients in the conventional f-URS group developed sepsis, whereas only 2 patients in the IFANS f-URS group experienced sepsis. Conclusion Compared with conventional f-URS, IFANS f-URS offers flexibility, incorporates negative-pressure suction, and enables real-time monitoring and regulation of intrarenal pelvic pressure. These advantages contribute to a higher stone-free rate and a reduced incidence of postoperative infections and related complications.