Abstract: Objective To compare the clinical efficacy and feasibility of flexible front-end controllable negative pressure suction ureteral sheath and conventional ordinary ureteral sheath combined with disposable electronic flexible ureteroscope in the treatment of upper urinary calculi.Methods The clinical data of 187 patients with upper urinary calculi who underwent surgical treatment in urology department of the People’s Hospital of Wuchuan from January 2023 to May 2024 were analyzed retrospectively.They were divided into two groups according to the different ureteroscope sheaths used.Among them,there were 93 cases in the flexible front-end controllable negative pressure ureteroscope group (experimental group) and 94 cases in the conventional flexible ureteroscope group (control group).The general information,treatment cost,hospitalization days before and after operation,residual stone rate after operation,postoperative complications and secondary stone removal rate were compared between the two groups.Results Compared with the control group,at the age of patients,BMI,hospitalization expenses,stone load surface area,preoperative hospitalization day,total hospitalization days,gender,preoperative hydronephrosis,basic diseases,ureteral injury or (and) subcapsular hematoma,these differences are not statistically significant(P>0.05).The proportions of patients with postoperative fever in the experimental group and the control group were 4.3% and 14.89% respectively, the proportions of patients with postoperative gross hematuria were 4.3% and 13.83% respectively, the proportions of patients with postoperative residual stones > 4mm were 10.76% and 19.05% respectively, and the proportions of patients with postoperative adjuvant drug treatment were 19.98% and 32.98% respectively. The proportions of patients undergoing secondary stone removal surgery after the operation were 9.68% and 24.47% respectively. There was a statistically significant difference between the two groups (P<0.05).Conclusion In the treatment of upper urinary calculi with flexible and controllable negative pressure at the front end,compared with the conventional ordinary ureteral sheath,it can significantly improve the clearance rate of upper urinary calculi with flexible ureteroscopy,reduce the postoperative meaningful residual stone rate and reduce the incidence of postoperative infectious complications,and it does not increase the hospitalization time and treatment cost of patients.

Key words: flexible controllable negative pressure suction ureteral sheath, upper urinary calculi, kidney calculi, disposable flexible ureteroscope, holmium laser