Comparison of Guy's Stone Score and clinical research of the endourological society nomogram for predicting surgical outcomes after pediatric percutaneous nephrolithotomy: a single center study

BACKGROUND: The aim of this study was to compare the efficacy of Guy's Stone Score (GSS) and Clinical Research of the Endoumlogical Society (CROES) Nomogram in predicting PCNL outcomes in the pediatric patients with kidney stone. METHODS: A retrospective review of the clinical data of 120 pediatric patients who underwent PCNL between August 2004 and February 2016 was performed. Patients were grouped according to stone-free (SF) status and complication status. The patients whose history, preoperative physical examination records. biochemical analysis, imaging records were available and who did not neglect the follow-up, were included in the study. The stone size measurement and the scoring system calculation were always performed by the same surgeon. Multivariate logistic regression analysis were performed to identify the factors associated with SF status and complication status. RESULTS: CROES score was significantly higher in SF patients compared to the patients with residual stones (P=0.009), while stone burden and GSS were significantly lower (P=0.023 and P=0.025). Median hospitalization day of patients with complications was significantly higher compared to the patients without complication (P=0.005). To have stones located in multiple calyces was the only statistically significant condition when two groups were compared (P=0.014). In multivariate analysis, CROES score was the independent factor associated with SF status (OR:0.984 95% CI: 0.959-1.010 P=0.017) and to have stones located in multiple calyces was the independent factor associated with complication status (OR:0.265 95% CI:0.087-0.808 P=0.02). CONCLUSIONS: CROES nomogram is associated with the SFR while GSS is not. Both scoring systems do not have predictive accuracy on complication status. Further studies are required to make modifications in the scoring systems in the pediatric population.