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The following is a summary of “Validation of Stone-Kidney Size Score to Predict Outcome and Complications of Pediatric Percutaneous Nephrolithotomy,” published in the August 2024 issue of Pediatrics by Aslan et al.
The increasing prevalence of urinary system stone disease in children underscores the necessity for minimally invasive treatment options to reduce morbidity and recurrence risk. Percutaneous nephrolithotomy (PCNL) has become a favored method for managing complex pediatric stones due to its minimally invasive nature, which is enhanced by innovations such as miniaturized and vacuum-assisted access sheaths, advanced laser technology, and tubeless or outpatient procedures. However, existing adult scoring systems have proven inadequate for predicting outcomes and complications in pediatric PCNL, highlighting the need for specialized scoring tools like the Stone-Kidney Size (SKS) scoring system. This study aims to evaluate the SKS scoring system’s effectiveness in predicting stone-free rates (SFR) and complications in pediatric PCNL.
Researchers conducted a retrospective review of 144 patients under 17 years of age who underwent PCNL between January 2008 and December 2019. The study group collected and analyzed data on demographics, stone characteristics, and perioperative and postoperative outcomes. The SKS scoring system, which includes the Stone-Kidney Index (SKI) and the number of stones, assigns one or two points based on whether the stones are single or multiple and whether the SKI value is below or above 0.3. The SKI is calculated by dividing the longest axis of the stone by the longest axis of the kidney. Residual stones smaller than 4 mm on non-contrast computed tomography are classified as clinically insignificant residual fragments (CIRFs). Success was defined as a stone-free status or presence of CIRFs. Investigators investigated the correlation between the SKS score and SFR, as well as complication rates post-surgery. Statistical analysis was performed using SPSS 22.0 software.
The overall SFR was 67.36%, which increased to 74.31% when patients with CIRF were included. The complication rate was 27%. Multivariate analysis revealed that a history of stone treatment, stone burden, and SKS score were significantly associated with SFR (p<0.001, p=0.032, p<0.001, respectively). Notably, the SKS score was the only variable with a statistically significant relationship with surgical success. No significant correlation was found between the SKS score and complication rates (p=0.342).
Our findings indicate that the SKS scoring system is related to SFR in pediatric patients with PCNL but has limitations in predicting post-PCNL complications. Although the study’s retrospective and single-center design may affect its generalizability, it validates the SKS system’s association with SFR in this context.
The SKS scoring system demonstrates a significant association with stone-free rates in pediatric patients undergoing PCNL; however, it does not predict complications effectively. Further studies are needed to enhance the predictive accuracy of scoring systems for post-operative complications in pediatric urology.
Source: sciencedirect.com/science/article/abs/pii/S1477513124004248
