Retrograde intrarenal surgery for pediatric upper urinary tract urolithiasis: A retrospective case series from a single center in Taiwan

To evaluate the outcomes of flexible ureteroscopy (FURS) in the treatment of upper tract urolithiasis in pediatric patients at a single medical institution in Taiwan. Pediatric patients aged ≤16 years who underwent FURS between November 2015 and November 2024 were included. Cases involving middle and lower ureteral stones were excluded. A retrospective analysis of demographic, preoperative, intraoperative, and postoperative data was conducted using electronic medical records. Stone-free status was defined as residual fragments being smaller than 4 mm on follow-up imaging. A total of 15 retrograde intrarenal surgery (RIRS) procedures were performed in 9 children (mean age, 10.87 years). The median cumulative stone diameter was 31 mm (interquartile range, 11.5–52.5 mm). Preoperative ureteral stenting was performed in 10 of 15 cases (66.67%). The ureteral access sheath placement was successful in 14 of 15 cases (93.33%), and all patients (100%) underwent successful RIRS with FURS. The median operative time was 98 minutes, and the median hospital stay was 3 days. Stone-free status was achieved in 9 patients, indicating an overall stone-free rate of 60%. Stratified by size, a stone-free rate of 81.81% was achieved in children with a cumulative stone diameter ≤5 cm, and 90% in the same group if the embedded renal parenchymal stones were excluded. No intraoperative complications were reported, and 2 patients (13.33%) experienced infection-related complications (Clavien II and IV). Advances in RIRS have facilitated its application in pediatric upper tract urolithiasis. When performed under appropriately selected conditions, FURS is a safe and effective treatment modality in this population.