First worldwide report on safety and efficacy of using small 7.5 Fr scope for pediatric ureteroscopy: prospective pilot series from Europe.

Introduction: Although pediatric urolithiasis remains relatively uncommon, its global prevalence is on the rise. Technological advances have led to miniaturization of instruments especially in the form of single use scopes. As the evidence on the use of small single use ureteroscopes in children is scarce, we have conducted a pilot two-center study to analyze the outcomes of pediatric patients treated with the Pusen 7.5 Fr single use scopes at our institutions. Material and methods: This study included consecutive pediatric patients with urinary stones treated with the small Pusen 7.5 Fr single use ureteroscope. The study was conducted at two large European tertiary endourology centers that specialize in pediatric kidney stone management. Patient data and outcomes were prospectively collected, and analysis was performed regarding patient demographics, stone parameters, as well as stone free rate (SFR), operating time, and complications. Results: In this pilot study, 26 patients were included with a median age of 12 years (7.0-16.0) and a male to female ratio of 14:12. The mean cumulative stone size was 15.15 mm (SD ±11.1) and multiple stones were present in 9 (34.6%) patients. Pre-operative stent, access sheath and post-operative stent usage was done in 12 (46.2%), 23 (88.5%) and 13 (50%) patients respectively. The median operative time was 47 minutes (IQR: 40.0-63.8). Following the initial procedure 24 (92.3%) patients were stone free, while no intra or postoperative complications were observed. Conclusions: Our study demonstrates that the use of the small 7.5 single use ureteroscope is safe and efficient for the treatment of urinary stones in pediatric patients with high stone-free rates and no complications noted in our series. While this might become a standard of care in future, to confirm and validate our findings further studies with larger cohorts are warranted.