Outcomes of retrograde ureteroscopy in Chinese infants and toddlers under 3 years old with ureteric stones from a single center.

Introduction: Pediatric urolithiasis is a less common disease with a steadily increasing incidence of 10.6 % per year. The comprehensive management of pediatric urolithiasis is more challenging than in adults, and published studies of endourological treatment in children have small sample sizes and older mean ages, which may not be representative of the overall pediatric population, especially in infants and toddlers. This study aimed to report results of retrograde ureteroscopy for treating pediatric ureteral stones in infants and toddlers (<3 years) from a single center in China.

Methods: Demographic and surgical data of infants and toddlers with ureteral stones who underwent retrograde URS were retrospectively analyzed from January 2015 to September 2022.

Results: The mean age of 100 infants (73 boys and 27 girls) was 19.6 ± 7.6 months and stone burden was 0.27 (0.11-0.52) cm³. 111 procedures were performed for all children due to 11 patients with bilateral ureteric stones were simultaneously treated. Among them, 70.3 % were semi-rigid URS, 12.6 % were Micro-URS and 17.1 % were flexible URS. SFR was up to 96 %, the median operation time and hospitalization days were 35.0 (25.0-50.0) minutes and 6.0 (5.0-6.0) days, respectively. 15 (15.0 %) infants had postoperative fever (Grade I), and complications above grade I were not observed.

Discussions: This research reported the largest sample size of infant and toddler ureteric stones (under 3 years old) and shared optimal management strategies for these special populations. Compared to other related studies, we had a higher SFR due to diverse management strategies and reasonable application of pre-operative ureteric stents. The most important potential reason why our complication rate was relatively higher might be the younger population under 3 years old. In additionally, the reason of long hospitalization was maybe some patients underwent staged surgeries during one hospitalization. Those results indicated the robust effectiveness of URS for infants. This study has limitations, including its retrospective single-center design, absence of long-term follow-up data, and potential variability in surgical outcomes due to differences in surgeons' experience.

Conclusions: The experience of endourologic procedures for 100 infant and toddler patients with ureteric stones from a Chinese single center was reported. And URS showed its effectiveness and safety for those special populations based on its high SFR and low complication rate.