Flexible ureteroscopy with a flexible and negative suction ureteral access sheath versus traditional sheath for treatment of infectious upper urinary tract stones: A prospective, randomized controlled study.

To evaluate the efficacy and safety of the flexible ureteroscopy (fURS) with a flexible and negative suction ureteral access sheath (FANS) versus traditional sheath for patients with infectious upper urinary tract stones (IUUTS). A total of 185 patients were enrolled, with 93 assigned to the FANS group and 92 to the traditional UAS group. The primary outcome was the stone-free rate (SFR) at the first postoperative day. Secondary outcomes included the SFR at 30 days postoperatively, operative time, hemoglobin reduction, length of hospital stay, quality of life (QoL) improvement, incidence of ureteral stricture at 3 months, and surgery-related complications. No significant differences were observed between the two groups in baseline demographics or preoperative clinical characteristics (P > 0.05). The FANS group had significantly lower white blood cell count, C-reactive protein, and procalcitonin levels at 6 and 24 h postoperatively (all P < 0.05). Mean operative time was significantly shorter (P < 0.001), QoL improvement was obviously greater (P < 0.001), and average hospital stay was shorter in the FANS group (P < 0.001). The SFRs on postoperative day 1 and at 30 days were both significantly higher in the FANS group (both P < 0.05). At 3 months, ureteral strictures occurred in three patients in the traditional UAS group and one in the FANS group, a difference that was not statistically significant (P > 0.05). The overall complication rate was significantly lower in the FANS group (P < 0.05). For patients with IUUTS, fURS combined with FANS effectively improves stone clearance efficiency and reduces the risk of postoperative infection.