A prospective comparative study of different nephrolithometric scoring system for nephrolithiasis to predict stone free status and complications in supine PCNL

The significant rise in stone disease has led to an increased popularity of percutaneous nephrolithotomy for the management of substantial stone burdens. Despite ongoing advancements in technology and surgical methods, overall complication rates of PCNL have gone up. For the best decision-making and well-informed patient counselling, a precise assessment of treatment success is essential. CT scans offer high-resolution spatial imaging that precisely characterizes stone size and distribution, pelvicaliceal anatomy, anomalies, and anatomical relationships. With these measurable stone and patient features, the Guy's Stone Score, S.T.O.N.E. score and CROES nephrolithometric nomograms have been introduced for systematic and quantitative assessment of kidney stones. There is no study evaluating the efficacy of these three scoring systems in patients undergoing supine PCNL. We prospectively analysed 100 patients over a period of 20 months (December 2022-July 2024). Analysis of relationship between residual calculus, Procedure Time (PT), Scope Time (ST), Fluoroscopy Time (FT) and duration of hospital stay and complications with different nephrolithometric scoring was done. ROC curve was drawn comparing all three scores. AUC for GSS is 0.711, STONE score is 0.705, and CROES score is 0.772 for predicting stone clearance. However, CROES score had highest sensitivity 97.3 but specificity and NPV of GSS is highest for predicting stone clearance with accuracy of 71.58%. For predicting complications AUC for GSS is 0.678, STONE score is 0.537, and CROES score is 0.591. Sensitivity of CROES is 95.7% but PPV, NPV, and accuracy is highest for Guy's stone score but data is insignificant. SFR in our study was 63%. SFR corroborated significantly with low Guy's score, low STONE score, and high CROES score. All three nomograms have statistically significant correlation with SFR. Except CROES Score, other two Scores have statistically significantly correlation with complications.