The Role of Renal Parenchymal Thickness and Tract Length on Mini-Percutaneous Nephrolithotomy Outcomes in Pediatric...

To evaluate the effects of renal parenchymal thickness (RPT) and tract length (TL) on the stone-free rate (SFR) and complications in pediatric patients who underwent minimally invasive percutaneous nephrolithotomy (mini-PCNL).

The data of pediatric age group (<18 years) patients who underwent mini-PCNL between 2017 and 2025 in our clinic, which is a tertiary referral center, were retrieved. Eighty patients were included in this study. SFR was determined using low-dose nonenhanced CT in all patients 1 month after procedure. Stone-free status was defined as the complete absence of stones, and the presence of any stone fragment, regardless of size, was defined as residual stone.

The mean stone diameter was 22.8 mm, and the mean stone burden was 402 mm². Although 46.3% of the stones were located only in the renal pelvis, 32.5% were staghorn. Mean RPT was 13.6 ± 5.0 mm, TL was 33.0 ± 10.5 mm, and RPT/TL ratio was 0.42 ± 0.13. Complications occurred in 27.5% of the patients. No major (grade 4-5) complications were observed in any patient. After mini-PCNL, stone-free status was achieved in 65% of patients. The mean diameter of residual stone was 3.4 ± 5.9 mm. When comparing patients who were stone free and those with residual stones, RPT (p = 0.059), TL (p = 0.315), and RPT/TL ratio (p = 0.563) were similar between groups. When patients with and without complications were compared, no statistically significant difference was found between the two groups in RPT (p = 0.084), TL (p = 0.589), and RPT/TL ratio (p = 0.723).

Mini-PCNL appears to be an effective and safe surgical technique that can be applied in pediatric patients with kidney stones, regardless of RPT and TL; however, prospective multicenter studies are necessary to confirm our results in a larger number of patients.