Many studies have focused on different scoring systems to predict stone-free status following endourological procedures. However, it remains unclear whether these systems can be applied to predict postoperative complications. In this study, we aim to evaluate five preoperative scoring systems for predicting complication rates after retrograde intrarenal surgery (RIRS).

We retrospectively analyzed patients who underwent RIRS from January to December 2023 at a single institution. Preoperative CT scans were used to assign scores using five systems (Guy's, S.T.O.N.E., CROES, R.I.R.S., SMASH). Postoperative complications were graded per the Clavien-Dindo classification. We compared complication and non-complication groups using standard statistical methods and performed univariate and multivariate logistic regression analyses. Areas under the curves (AUC) for Receiver Operating Characteristic (ROC) curves were calculated to assess each scoring system's predictive value.

A total of 115 patients were included, with an overall complication rate of 31.3%. Most complications were grade I or II, such as fever and urinary tract infection. Three patients experienced bacteremia, and one had septic shock requiring intensive care. Hematomas were noted in two patients, one needing transcatheter arterial embolization. Only the CROES score differed significantly between groups (p=0.0166). Logistic regression indicated no significant association between the scoring systems and complication rates. AUC values for ROC curves were low: 0.608 (Guy's), 0.598 (S.T.O.N.E.), 0.407 (CROES), 0.573 (R.I.R.S.), and 0.584 (SMASH).

Despite a significant difference in the CROES score, none of the five scoring systems effectively predicted postoperative complications. Further research is needed to develop a new model based on these systems for better predictive performance.