The use of ureteral wall thickness for predicting the presence of distal ureter impacted stones in patients with ureteral stones undergoing ureteroscopic lithotripsy

Objective To evaluate the significance of ureteral wall thickness(UWT) for predicting the presence of distal ureter impacted stones in patients with ureteral stones undergoing ureteroscopic lithotripsy(URSL). Methods We retrospectively analyzed 320 procedures in patients with distal ureter impacted stones who underwent URSL between February 2014 and February 2018.Maximum UWT at the stone site was measured from computed tomography images.Receiver operating characteristic curve analysis was applied to determine the UWT cutoff value and to evaluate its accuracy in predicting impacted stones. Results Of the 320 patients, 119 involved patients with impacted stones.The univariate analysis showed significant differences in perirenal exudation, stone number and size and UWT.The receiver operating characteristic curve analysis showed that 3.15 mm was the optimal cutoff value for UWT, with a predictive accuracy of 0.94. Conclusions UWT is associated with surgical outcomes in patients with distal ureter impacted stones ondergoing URSL. Key words: Ureteral Calculi; Urethral Obstruction; Ureteroscopy; Ureteral wall thickness