Impact of case volume on outcomes of ureteroscopy for ureteral stones: the clinical research office of the endourological society ureteroscopy global study.

Background: The Clinical Research Office of the Endourological Society (CROES) undertook the Ureteroscopy Global Study to establish a prospective global database to examine the worldwide use of ureteroscopy (URS) and to determine factors affecting outcome.

Objective: To investigate the influence of case volume on the outcomes of URS for ureteral stones.

Design, Setting, And Participants: The URS Global Study collected prospective data on consecutive patients with urinary stones treated with URS at 114 centres worldwide for 1 yr. Centres were identified as low or high volume based on the median overall annual case volume.

Outcome Measurements And Statistical Analysis: Pre- and intraoperative characteristics, and postoperative outcomes in patients at low- and high-volume centres were compared. The relationships between case volume and stone-free rate (SFR), stone burden, complications, and hospital stay were explored using multivariate regression analysis.

Results And Limitations: Across all centres, the median case volume was 67; 58 and 56 centres were designated as low volume and high volume, respectively. URS procedures at high-volume centres took significantly less time to conduct. Mean SFR was 91.9% and 86.3% at high- and low-volume centres, respectively (p<0.001); the adjusted probability of a stone-free outcome increased with increasing case volume (p<0.001). Patients treated at a high-volume centre were less likely to need retreatment, had shorter postoperative hospital stay, were less likely to be readmitted within 3 mo, and had fewer and less severe complications. At case volumes approximately >200, the probability of complications decreased with increasing case volume (p=0.02). The study is limited by the heterogeneity of participating centres and surgeons and the inclusion of patients treated by more than one approach.

Conclusions: In the treatment of ureteral stones with URS, high-volume centres achieve better outcomes than low-volume centres. Several outcome measures for URS improve with an increase in case volume.

Patient Summary: Outcomes following treatment of ureteral stones by ureteroscopy (URS) were studied in a large group of patients at centres worldwide. The proportion of successful procedures (ie, those in which patients became stone free) increased as the annual volume of URS at a hospital increased. Hospital stays were shorter and postoperative complications were less likely at high-volume hospitals. We conclude that for URS, the best outcomes are seen in patients treated at high-volume hospitals.