Computed tomography–based prediction of ureteroscopic failure in impacted ureteral stones: A focus on stone volume and ureteral anatomy

Abstract

Introduction

Impacted ureteral stones are associated with lower ureteroscopic success and increased procedural complexity. Although ureteroscopy is the standard treatment, reliable preoperative predictors of failure are limited, and decision-making often depends on intraoperative findings. This study evaluated the association between preoperative CT-based stone and ureteral anatomical parameters and ureteroscopic failure among patients with endoscopically confirmed impacted ureteral calculi.

Methods

This retrospective study analyzed 123 patients with impacted ureteral calculi who underwent URS. Preoperative non-contrast computed tomography images were evaluated for stone characteristics, ureteral wall thickness (UWT), and ureteral anatomical features, including kinking. URS success was defined as stone-free status after the initial procedure, and the predictive value of CT parameters was assessed using receiver operating characteristic analysis and univariate and multivariate logistic regression models.

Results

The overall URS success rate was 68.3%. In univariate analysis, stone volume, proximal kink width, and proximal kink length were significantly larger in the failed group. Multivariate logistic regression analysis identified stone volume as the sole independent predictor of URS failure (OR: 3.05; 95% CI: 1.06–8.78; P = .039). A stone volume ≥ 451.28 mm³ demonstrated modest predictive power (AUC = 0.615). Although proximal kink parameters showed promising results in univariate analysis and ROC curves, these associations were not independent of other factors. UWT showed no significant differences between the groups.

Conclusions

Stone volume is the only independent predictor of ureteroscopic failure in impacted ureteral stones, while ureteral anatomy may provide complementary information regarding procedural complexity.