Abstract
Single-use flexible ureterorenoscopes (fURSs) exhibit differences in key technical features such as deflection degree, irrigation flow rate, and optical resolution, despite general similarities. However, few studies have compared different single-use fURS models in vivo. This study aimed to compare the surgical outcomes of 5 different fURSs: Pusen PU3022A (model 1), Lithovue Boston Scientific (model 2), Scivita SUV-2A-B (model 3), Redpine RP-U-C0304 (model 4), and Hugemed HU30 (model 5) in patients undergoing retrograde intrarenal surgery for renal and proximal ureteral stones. In this analytical cross-sectional study, we retrospectively evaluated 196 patients who underwent retrograde intrarenal surgery between December 2021 and January 2024, grouped by the fURS model used. Demographic, stone-related, and surgical variables were compared across groups. Statistical analyses included the Kruskal-Wallis test, χ2 test with Bonferroni correction, and logistic regression to adjust for confounding factors. Model performance was assessed using goodness-of-fit and predictive accuracy measures. While the groups were similar in terms of age, gender, stone density, laterality, and operative time, significant differences were found in stone length, localization, and hydronephrosis. The overall stone-free rate (SFR) significantly differed between groups (P = .00044). Post hoc analysis showed a significant SFR difference only between model 1 and model 5; however, after adjustment for confounding factors, model 4 emerged as the only independent predictor of higher SFR, highlighting the disparity between unadjusted and adjusted analyses. These findings suggest that device choice can influence surgical success and that adjusting for confounders is essential for accurate interpretation of outcomes.