Prediction of Surgical Outcome as Regards Stone Free Rate and Complications after Percutaneous Nephrolithotomy Using S. T. O. N. E. versus sResc Scoring Systems

Abstract
Background: Nephrolithiasis is a major worldwide source of morbidity, constituting a common urological disease affect-ing 10-15% of the world population. Aim of Study: To compare the S.T.O.N.E versus sResc scoring system in prediction of the surgical outcome as regards stone free rate and complication after PCNL. Patients and Methods: A prospective randomized clinical study conducted in Department of Urology, Faculty of Med-icine, Ain Shams University Hospitals. Study period was 6 months from 3-2020 till 9-2020. Results: STONE total score involved size, tract length, degree of obstruction, number of involved calyces and stone density. STONE score was 6.8±1.7. S-ReSC total score was 3.1±1.6. A significant statistical association between both scores was found (c2: 119.681, p < 0.001). Mean STONE score was 6.19±1.20 compared to 7.92±1.89 in free and residual group of patients respectively (t: 4997; p < 0.0001). Mean S-ReSC score was 2.14±0.88 compared to 4.76±1.30 in free and residual group of patients respectively (t: 4997; p < 0.0001). Both scores were higher significantly in patients with residual stones. The ROC curve shows that the best cut off point for S-ReSC score to detect residual free rate was found >2 with sensitivity 100%, specificity 76.19% and Area Under Curve (AUC) 95% while the best cut off point for STONE score to detect residual free rate was found >6 with sensitivity 70.3%, specificity 68.3% and Area Under Curve (AUC) 76.4%. Conclusion: Both S-ReSC and S.T.O.N.E Nephrolithom-etry Scores can be used to stratify the complexity of renal stone before PCNL to predict the stone clearance and compli-cation.