Objective To explore the therapeutic effect of flexible ureteroscopic lithotripsy(FURL)by using flexible ureteroscope combined with flexible vacuum suction ureteral access sheath in the treatment of renal calculi with diameter 3-4.5 cm and CT value≤1000 HU.Methods A Retrospective analysis was conducted on clinical data of 42 patients with 3-4.5 cm renal calculi and CT value≤1000 HU from March 2023 to March 2025.A disposable flexible ureteroscope combined with flexible vacuum suction ureteral access sheath was used to fragment the calculi with holmium laser,and the fragments were then aspirated.Results Two cases had their stones left untreated when the operation time exceeded 2.5 h,resulting in the termination of the surgery.The remaining40 cases were successfully treated with the operation.The operation time was 85-150 min,with an average of(113.9±17.8)min.The postoperative hospital stay was2-5 d,with an average of(2.2±0.6)d.Postoperative fever occurred in 2 cases,and hematuria appeared in 5 cases,all of which were cured by conservative treatment.On the first postoperative day,residual stones were found in 4 cases.At 1 month after surgery,residual stones were detected in 3 cases.One case was treated with extracorporeal shock wave lithotripsy(ESWL)and the stones were expelled after 1 month.The other 2 cases(those whose surgery was terminated)underwent a second FURL and achieved successful stone clearance.Conclusion FURL for 3-4.5 cm renal calculi with CT value≤1000 HU by using flexible ureteroscope combined with flexible vacuum suction ureteral access sheath is safe and effective.

Objective To explore the therapeutic effect of flexible ureteroscopic lithotripsy(FURL)by using flexible ureteroscope combined with flexible vacuum suction ureteral access sheath in the treatment of renal calculi with diameter 3-4.5 cm and CT value≤1000 HU.Methods A Retrospective analysis was conducted on clinical data of 42 patients with 3-4.5 cm renal calculi and CT value≤1000 HU from March 2023 to March 2025.A disposable flexible ureteroscope combined with flexible vacuum suction ureteral access sheath was used to fragment the calculi with holmium laser,and the fragments were then aspirated.Results Two cases had their stones left untreated when the operation time exceeded 2.5 h,resulting in the termination of the surgery.The remaining40 cases were successfully treated with the operation.The operation time was 85-150 min,with an average of(113.9±17.8)min.The postoperative hospital stay was2-5 d,with an average of(2.2±0.6)d.Postoperative fever occurred in 2 cases,and hematuria appeared in 5 cases,all of which were cured by conservative treatment.On the first postoperative day,residual stones were found in 4 cases.At 1 month after surgery,residual stones were detected in 3 cases.One case was treated with extracorporeal shock wave lithotripsy(ESWL)and the stones were expelled after 1 month.The other 2 cases(those whose surgery was terminated)underwent a second FURL and achieved successful stone clearance.Conclusion FURL for 3-4.5 cm renal calculi with CT value≤1000 HU by using flexible ureteroscope combined with flexible vacuum suction ureteral access sheath is safe and effective.