# Micro-URS Experience in the Treatment of Distal Ureteral Stones in Preschool-Aged Children

## TL;DR

This study shows that micro-ureteroscopy is a safe and effective treatment for kidney stones in young children.

## Contribution

Demonstrates micro-URS as a first-line treatment for distal ureteral stones in preschool-aged children.

## Key findings

- All patients were stone-free after one month with minimal complications.
- Micro-URS outperforms Shock Wave Lithotripsy in treating pediatric kidney stones.
- Reintervention was needed in 22.8% of cases for minor complications.

## Abstract

Objective: The incidence of urolithiasis in the paediatric population is rising, leading to a progressive shift towards minimally invasive management strategies. This study evaluated the efficacy and safety of using micro-ureteroscopy (micro-URS) to treat distal ureteral stones in preschool-aged paediatric patients. Methods: A retrospective analysis was conducted on 57 children (aged 6–72 months), all of whom had undergone micro-URS treatment for distal ureteral stones between September 2022 and April 2024. Patient demographics, along with perioperative and postoperative outcomes, were assessed. Stone fragmentation was achieved using a 4.85 Fr micro-ureteroscope and a 200 μm Ho:YAG laser fibre. Postoperative complications were graded according to the Clavien–Dindo classification system, and stone-free status was confirmed for each patient at their one-month follow-up appointment. Results: The mean patient age was 44.2 months, and the median stone size was 9.4 mm (range: 6–24 mm). Stone-free status was confirmed in all patients at their one-month follow-up appointment. In 22.8% of cases, reintervention was required to address minor complications, including haematuria (n = 6), urinary tract infections (n = 4), and stone migration (n = 3). No major intraoperative complications were observed. A total of 41 patients (71.9%) required a double-J stent to treat intraoperative oedema or stone impaction. The mean operative time was 28.6 min, and the mean hospitalisation duration was 19.7 h. Conclusions: Micro-URS achieved a 100% stone-free rate with minimal complications, establishing it as a safe and highly effective option for treating distal ureteral stones in preschool-aged children. These findings show that micro-URS offers advantages over Shock Wave Lithotripsy (SWL) in paediatric urolithiasis management, supporting it as a first-line treatment modality. Further prospective, randomised studies are needed to validate these results.