Ureteral Stone Impaction with Its Possible Effects on the Outcomes of Endoscopic Management in Children: A Critical Evaluation with an Emphasis on Ureteral Wall Thickness.

Introduction: Ureteral stone impaction can significantly affect the success of ureteroscopy (URS) in children. While the factors predicting impaction have been well studied in adults, data in children are limited. This study aimed to identify factors that predict ureteral stone impaction in children undergoing URS and to compare the success rates and complications based on the stone impaction status. Patients and Methods: Pediatric patients undergoing URS for ureteral stones were retrospectively reviewed. Impaction status of the stones was evaluated by radiological parameters and the children were divided into two groups based on the presence of stone impaction. Peri- and postoperative findings were comparatively evaluated in patients with or without stone impaction. Results: A total of 102 pediatric patients were included (40 with impacted stones, 62 with nonimpacted ureteral stones). The mean age was 9.3 ± 5.3 years. Univariate analysis showed significant differences between the groups in degree of hydronephrosis, presenting symptoms, stone density (HU), stone size, upper ureteral diameter, and that of ureteral wall thickness (UWT) (p = 0.004, p = 0.044, p = 0.033, p = 0.005, p = 0.012, p = 0.000, respectively). Multivariate analysis revealed UWT as the only independent predictor of stone impaction, with a cutoff value of 2.63 mm showing 83% sensitivity and 82% specificity (p = 0.000). The highest UWT value in the nonimpacted stone group was 3.1 mm. The mean operation time was found to be significantly longer in cases with impacted stones (p = 0.000). Kids with impacted stones had lower mean success rate (impacted = 70%, nonimpacted = 88.7%) and higher mean rate of complications, longer duration of DJ-stenting, more anesthesia sessions (p = 0.018, p = 0.019, p = 0.000 and p = 0.000, respectively). Conclusions: Similar to the adult cases, UWT could be used as a reliable parameter in predicting the impaction status of ureteral stones in pediatric patients. Impacted ureteral stones may reveal decreased success and higher complications rates during and after endoscopic stone surgery in these cases.