Comparison of scoring systems for predicting stone-free status and complications after retrograde ıntrarenal surgery

Abstract

Purpose: To compare the effectiveness of scoring systems in predicting stone-free rates (SFR) and complications following retrograde intrarenal surgery (RIRS).

Materials and methods: We retrospectively analyzed 280 patients who underwent RIRS for kidney stones between 2016 and 2019. The Resorlu-Unsal Stone score (RUSS), Modified Seoul National University Renal Stone Complexity (S-ReSC) score, and R.I.R.S. scoring system score were calculated for each patient who was enrolled in the study. Subsequently, stone scoring systems were compared as to their predictive capability for SFR using receiver-operating characteristic curves. Furthermore, multivariate analysis was done to determine whether the scoring systems associated with SFR and complications.

Results: The median patient age was 44 (35--56). The median RUSS, S-ReSC, and R.I.R.S scores were 0 (0-1), 1(1-2), and 6 (5-7), respectively. The overall SFR was 76.7%. The R.I.R.S. scoring system was found to have a higher predictive value in predicting postoperative SFR than the other two scoring systems (p < 0.001, AUC = 0,816). RUSS, R.I.R.S. score, and stone size were found to be independent predictive factors for SFR (p = 0.049, p = 0.024, p = 0.033, respectively). Complications were observed in 3.2%(9/280) of patients. Stone scoring systems were not statistically associated with complications. Operation duration was the only independent risk factor for complications (p = 0.010).

Conclusions: The R.I.R.S. scoring system was found to have a higher predictive value than RUSS and S-ReSC to predict SFR following RIRS in our study. However, none of the stone scoring systems was directly proportional to complications of RIRS.

Keywords: Laser lithotripsy; Renal calculi; Scoring methods; Treatment outcome; Ureteroscopy.