Prospective Evaluation of Outcomes and Complications in Ultra-Mini-Percutaneous Nephrolithotomy for Pediatric Nephrolithiasis: A Three-Year Study

Objective: This prospective study aimed to evaluate the outcomes and complications of Ultra-Mini Percutaneous Nephrolithotomy (UM-PCNL) in pediatric patients with renal calculi over a three-year period (2021-2023). We assessed Stone-Free Rates (SFR), operative success and perioperative complications to determine the efficacy and safety of UM-PCNL in children. Methods: Seventy-eight pediatric patients (aged 1-17 years) underwent UM-PCNL for renal calculi larger than 10 mm. Preoperative imaging, including ultrasonography and computed tomography, was utilized to assess stone size and location. Surgical outcomes, including SFR, operative time and the need for second-look procedures, were evaluated. Complications were graded using the Clavien-Dindo classification. Statistical analysis was conducted using SPSS, with a significance threshold of p < 0.05. Results: The mean stone size was 18.2 ± 5.4 mm and the overall SFR after a single UM-PCNL procedure was 78.2%. Clinical success (defined as either stone-free status or clinically insignificant residual fragments) was achieved in 89.7% of patients. The mean operative time was 67 ± 22 minutes. Second-look procedures were required in 11.5% of cases. The overall complication rate was 19.2%, with no major complications (Clavien grade III-V). Minor complications included transient fever (6.4%), hematuria (12.8%) and urinary leakage (5.1%). Conclusion: UM-PCNL is a safe and effective procedure for managing pediatric nephrolithiasis, offering high stone-free rates and low complication risks. The use of smaller instruments reduces renal trauma, bleeding and the need for blood transfusions. These findings support UM-PCNL as a first-line treatment option for larger renal stones in pediatric patients. Further studies with long-term follow-up are recommended to assess recurrence and long-term renal function outcomes.