SHA.LIN Renal Stone Scoring System for Predicting Stone Free Status and Postoperative Outcomes after Percutaneous Nephrolithotomy

Abstract Objective: To introduce a novel renal stone scoring system (SHA.LIN) for percutaneous nephrolithotomy (PCNL) and compare the predictive power of SHA.LIN, Guy’s, and S.T.O.N.E. scoring systems for postoperative outcomes.Methods: Six reproducible parameters available from preoperative computed tomography were measured: stone burden (S), hydronephrosis (H), anatomic distribution (A), length of tract (L), indicator of CT (I), and number of involved calics (N). We retrospectively reviewed data of patients who underwent PCNL from May 2018 to January 2021. SHA.LIN, S.T.O.N.E. and Guy’s scores correlation with stone free-status (SFS), Hemoglobin change, estimated blood loss (EBL), operation time (OT), and postoperative hospitalization time (PHT) was evaluated using standard statistical methods.Results: The overall SFS was 69.7% (248/356), and complications occurred in 110 (30.9%). In patients with stone-free group vs. non stone-free group, the median (IQR) of Guy’s score was 2 (1-2) and 3 (2-3), S.T.O.N.E. score was 6 (6-8) and 8 (7-9.5), and SHA.LIN score was 7 (7-9) and 11 (10-12.5), respectively (each p <0.001). Regression analysis showed that three scoring systems were significantly associated with SFS and OT. None of them was significantly correlated with PHT. EBL and hemoglobin change were found significantly correlated with SHA.LIN. Receiver Operating Characteristics (ROC) curves showed three scoring systems had comparable predictive accuracy for SFS and complications, with SHA.LIN having highest Area Under the ROC Curve (AUC) value (0.852 and 0.774). ROC analysis area AUC demonstrated more accurate prediction of EBL based on the SHA.LIN (0.807) than the other two scoring systems.Conclusion：SHA.LIN scoring system can accurately predict postoperative outcomes of PCNL and can be used as an adjuvant tool for surgical planning. Three scoring systems are well associated with SFS and OT and in addition, SHA.LIN is also significantly associated with surgical bleeding risk.