Retrospective analysis of flexible ureteroscopic lithotripsy using end-fire, flexible negative-pressure ureteral access sheath for the management of 2–3-cm kidney stones

Objective To compare the efficacy and safety of flexible ureteroscopic lithotripsy using end-fire flexible negative-pressure ureteral access sheath (F-UAS) versus traditional ureteral access sheath (T-UAS) for 2–3-cm kidney stones. Methods This retrospective case–control study included 136 patients with kidney stones treated with flexible ureteroscopic lithotripsy using F-UAS at Shenzhen Second People’s Hospital from November 2022 to November 2023 (F-UAS group) and 132 patients treated with flexible ureteroscopic lithotripsy using T-UAS from November 2021 to October 2022 (T-UAS group). Preoperative assessments included imaging studies (kidney, ureter, and bladder X-ray; noncontrast computed tomography; and renal ultrasound) and laboratory tests (complete blood count, biochemical tests, coagulation function, and urine culture). The stone clearance rate, operation time, intraoperative blood loss, and complications were compared between the two groups. Results Baseline characteristics of the two groups were balanced. The F-UAS group showed significantly higher stone clearance rate (91.9% vs. 81.8%, p = 0.014), shorter operation time (51.0 ± 13.9 vs. 59.8 ± 18.2 min, p < 0.001), and lower postoperative antibiotic use (2.9% vs. 6.8%, p = 0.027) than the T-UAS group. The intraoperative blood loss and length of hospital stay did not differ significantly between the two groups. Conclusions Flexible ureteroscopic lithotripsy using F-UAS improves stone clearance, reduces infection-related complications, and shortens operation time compared with that using T-UAS in the treatment of 2–3-cm kidney stones. Further prospective studies are warranted to confirm these findings.