The surgical experience influences the safety but not efficacy of rirs for kidney stones: a propensity score analysis: mp50‐11

INTRODUCTION AND OBJECTIVES: The safety and the efficacy of Retrograde IntraRenal Surgery (RIRS) is influenced by many factors such as stone burden and location but also by technical skills of the operating surgeon . The aim of this study is to evaluate if the surgeon experience could influence the outcomes of RIRS in terms of stone clearance and complication rate. METHODS: Data of patients who underwent RIRS for kidney stones were prospectively collected. Cases were divided in 2 groups. Group 1: cases operated by 3 surgeons in the early phase of learning curve (surgical experience less than 100 RIRS); Group 2: cases operated by two surgeons with a great experience in endourology (>400 RIRS). Patients and stone data, results and safety outcomes were analyzed. Multivariable regression model was used. Differences between groups was estimated using propensity scores to adjust for the bias inherent to the different patient characteristics RESULTS: 381 RIRS were analyzed (Group 1: 150 RIRS; Group 2: 231 RIRS). The clinical data and stone parameters were comparable between 2 groups (Table1). The SFR was 70% in Group 1 and 77.9% in Group 2 (p1⁄40.082). Operative time was significantly shorter in the Group 2 (76.3 vs. 53.1min, p1⁄40.001). The overall complication rate was significantly lower in Group 2 (20.7 vs. 8.7 p1⁄40.001) (Table 2). At unadjusted analysis, a non significant difference was found between centers on SFR (OR 1.51 95%CI 0.95 to 2.41). Conversely, a significant difference was found on overall complications at unadjusted analysis (OR 0.36 95%CI 0.20 to 0.67) with lower overall complication in Group 2. Both results were confirmed by propensity score analysis (Fig.1 and Fig.2). CONCLUSIONS: This study shows that surgeon experience influences the outcomes of RIRS mainly in terms of safety. Further studies will be needed to assess the exact number of procedures necessary to obtain a plateau in the rate of complications and success Source of Funding: none