Does Shock Wave Application Affect the Ureteral Wall Around an Impacted Stone? A Critical Evaluation Focusing on Ureteral Wall Thickness

<b>Background/Objectives</b>: The aim of this study was to evaluate the possible effects of shock wave (SW) application for the noninvasive treatment of impacted ureteral stones on the pericalcular ureteral tissue in terms of changes in ureteral wall thickness. <b>Methods</b>: A total of 114 patients with impacted proximal ureteral stones underwent ESWL at our department. Patient- and stone-related parameters (size, density, and location); radiological parameters, including ureteral wall thickness (UWT); and degree of hydronephrosis were assessed on NCCT images before and shortly after the procedure. The possible effects of applying high-energy shock waves to the pericalcular ureteral tissue were evaluated according to changes in ureteral wall thickness. A comparative evaluation was conducted based on the number of sessions and the outcomes of SWL. <b>Results</b>: The mean value of UWT after the first session of stone management decreased significantly when compared to the mean pre-operative value (<i>p</i> < 0.005). This was also noted after the second treatment session, after which the mean UWT was significantly lower than the pre-operative value (<i>p</i> < 0.005). However, the difference in the mean UWT before and after three sessions of SWL was not significant (<i>p</i> = 0.104). A detailed evaluation of these values in all groups revealed that although the decrease in the mean UWT in cases with a successful outcome was significant (<i>p</i> < 0.005), the change in these values was not significant in cases for which the treatment was unsuccessful (partial disintegration of the stone or no disintegration at all) (<i>p</i> = 0.145). <b>Conclusions</b>: Application of SW in patients with impacted upper ureteral stones may not have a detrimental effect on the ureteral wall or compromise a secondary procedure if the stones are successfully disintegrated and passed after one or two sessions. However, in the case of resistant stones, an increased number of sessions and more SWs may induce such adverse effects, warranting further evaluation in future studies.