The Efficacy of Guy's Stone Score for Predicting the Stone-Free and Complication Rates in Children Treated by Percutaneous Nephrolithotomy.

Introduction: To determine the efficacy of Guy's stone score (GSS) for predicting stone-free and complication rates after percutaneous nephrolithotomy (PCNL) in children. Patients and Methods: A total of 197 renal units (RUs) in 173 children (≤17 years) who referred to our clinic were included in our study. RUs with stones were classified as four groups according to GSS. The results were designated as stone free or as having residual stones. Complications were evaluated according to GSS, the Satava, and modified Clavien grading system. All parameters were evaluated by using univariate and multivariate analysis. Results: The median age of patients was 6 years (1-17 years). Stone-free status was 77% and complication rate was 17%. Stone-free rate was established 89% for group 1, 78% for group 2, 75% for group 3, and 57% for group 4. There was a positive association between GSS and stone-free status (p = 0.02). No relationship was found between GSS and the complication rate (p = 0.42). In multivariate analysis, GSS was the only independent factor for predicting stone-free status. Conclusion: Current study revealed that GSS has a predictive ability for stone-free status; however, GSS is insufficient for predicting complications after pediatric PCNL. Even though, GSS does not fully reflect the characteristics of the pediatric population, we believe that it might provide useful insights for clinicians when recommending and discussing treatment options for children with urolithiasis.