Ureterorenoscopy performed by residents under expert supervision: a training approach ensuring patient safety and effectiveness

to evaluate the outcomes and postoperative complications of ureteroscopy (URS) and retrograde intrarenal surgery (RIRS) for urolithiasis performed by residents under supervision compared to those performed by specialists. The institutional endourology database was reviewed. Patients, stone characteristics – including Guy's stone (GSS) and S.T.O.N.E. scores to describe the complexity of renal stones – perioperative and postoperative data, complications, and stone-free rate (SFR) were retrieved. Procedures were stratified based on whether a specialist or a supervised resident performed them. Multivariate logistic regression was used to analyze the association between stone characteristics and/or operator, and SFR. Out of 280 patients analyzed, 164 (58.6%) were operated on by specialists vs. 116 (41.4%) by supervised residents. Specialists treated larger stones (p < 0.04), but GSS and S.T.O.N.E. scores showed no significant differences. Supervised residents performed more URS than specialists (23.3% vs. 13.4%, p = 0.038). Operative time was shorter for supervised residents (70 vs. 75.5 min, p = 0.02). Patients operated by specialists were more likely discharged with indwelling ureteral stent (82.3% vs. 69.8%, p = 0.02), for a longer time (p = 0.004). Complication rates were similar, but patients operated by specialists had more stone-related events within 90 days (29.9% vs. 16.4%, p = 0.01). SFR was 58.5% for specialists and 63.8% for supervised residents (p = 0.4). Stone volume and stones' multifocality were predictors of a poorer SFR, while an operation performed by a supervised resident was not a predictor (p = 1). Under the controlled environment and careful case selection typical of a supervised residency training program, resident-performed ureterorenoscopy for urolithiasis is safe and yields satisfactory postoperative outcomes.