The Stone Kidney Size (SKS) Score Breakthrough: A Simple Yet Powerful Tool to Predict Success and Safety Outcomes in Pediatric Mini Percutaneous Nephrolithotomy (PCNL)
TL;DR
The SKS score is a simple, non-invasive, and reproducible tool that could be evaluated preoperatively with the use of Ultrasound KUB and has good predictive ability for stone clearance and postoperative complications.
Abstract
Mini percutaneous nephrolithotomy (PCNL) is now considered one of the important treatment modalities for large renal stones or stones that are refractory to other treatments. Objective: To evaluate the predictive accuracy of the Stone Kidney Size (SKS) score for the prediction of the success rate of mini PCNL in the pediatric population. Methods: A prospective cross-sectional validation study was conducted at Tabba Kidney Hospital for a period of 7 months (from June 2025 to December 2025). A total of 124 children aged 1–14 years with unilateral renal stones were included. SKS score was calculated preoperatively using Ultrasound KUB based on the number of stones and Stone Kidney Index (SKI). Statistical analysis included chi-square test, logistic regression, and ROC curve analysis. Results: The mean age of the participants was 6.05 ± 3.32 years, and 67.7% male predominance was observed. Overall, the stone clearance rate was 81.4%. A total of 19% patients experienced postoperative complications, with a higher proportion in patients with a SKS score of ≥ 6 (P=0.034). The SKS score was found to be an independent predictor of incomplete stone clearance (p<0.001) with good predictive accuracy on ROC analysis. Conclusions: The SKS score is a simple, non-invasive, and reproducible tool that could be evaluated preoperatively with the use of Ultrasound KUB. It has good predictive ability for stone clearance and postoperative complications.