Purpose: To evaluate the clinical significance of ureteral wall thickness (UWT) for predicting spontaneous passage (SP) of uncomplicated ureteral stones of ≤ 10 mm.
Methods: We retrospectively reviewed 418 patients with a diagnosis of uncomplicated ureteral stones who presented to Kori Hospital from 2011 to 2018. The maximum stone diameter and UWT at the stone site were measured from axial computed tomography images. Clinical predictors of 4-week SP were assessed using univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis was applied to evaluate the accuracy of factors in predicting SP of ureteral stones.
Results: Of the 418 patients, 202 (48.3%) spontaneously passed their stones within 4 weeks of their initial visit. Multivariate analysis showed that stone location, stone size, and UWT (odds ratio, 0.40; P < 0.001) were independent predictors of 4-week SP. ROC analysis showed that 2.71 mm was the optimal cut-off value for UWT, with a predictive accuracy of 0.83. Low UWT had a significantly higher 4-week SP rate than high UWT (76.4% vs. 14.7%, respectively; P < 0.001). In addition, high UWT was associated with a higher risk of stone-related complications within 4 weeks compared with low UWT (16.4% vs. 7.2%, respectively; P = 0.0044).
Conclusions: UWT can serve as a potential predictive factor for 4-week SP and may help physicians to select patients who require immediate interventions among those with ≤ 10-mm ureteral stones.
Keywords: Predictive factor; Spontaneous stone passage; Ureteral stone; Ureteral wall thickness.