Impact of previous SWL on ureterorenoscopy outcomes and optimal timing for ureterorenoscopy after SWL failure in proximal ureteral stones

Purpose: We aimed to evaluate the impact of previous unsuccessful shock wave lithotripsy (SWL) therapy on ureterorenoscopy (URS) outcomes in proximal ureteral stones and to define whether there is any optimal timing for safe URS after SWL. Methods: The patients who underwent URS for proximal ureteral stones between the years 2015 and 2018 in eight centers were included. Patients were divided into two groups according to previous SWL history; group 1 consisted of patients without SWL before URS for the stone [SWL (-)] and group 2 consisted of patients with a previous SWL for the stone [SWL (+)]. Demographics, operation outcomes and stone characteristics were compared between these two groups. Regarding the complication and success rates, optimal timing for URS after SWL for the stone was calculated with receiver operator characteristics curve analysis. Results: Totally 638 patients were included (group 1: 466 patients and group 2: 172 patients). The operation and hospitalization times, rate of ureteral stenting and complications were significantly higher in group 2. Stone free status was similar between the groups. Optimal timing for URS after SWL was calculated as 16.5 days (AUC = 0.657, p = 0.012) with a sensitivity of 68% and specificity of 72%, regarding the complication rates. Complication rates were significantly higher in patients who were operated before 16.5 days (27.7% vs 6.5%, p < 0.001). Conclusions: The optimal timing; 2–3 weeks delay of the URS procedure after unsuccessful SWL may decrease complication rates according to our results. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.