Predictive factors for success of ultrasound-guided percutaneous nephrolithotomy

Background: Given the cumulative harmful effects of radiation over time, the use of alternative imaging modalities to safely guide percutaneous nephrolithotomy (PCNL) has become increasingly relevant.Objective: The objective of this study was to identify clinical and radiographic factors that predict the success of ultrasound-guided PCNL (USG-PCNL), defined as a stone-free state.Materials and methods: This retrospective study included 115 patients treated with USG-PCNL between January 2021 and November 2022.Clinical and nephrolithometric variables obtained from computed tomography were analyzed.The association between these variables and residual stone burden was evaluated using multiple linear regression and receiver operating characteristic (ROC) curve analysis.Results: Stone-free status was achieved in 73% of patients.Residual stones were significantly associated with a stone burden > 3290 mm 3 (OR: 6.0) and involvement of ≥3 renal calyces (OR: 4.9).Multivariate analysis and ROC curves showed good predictive power (area under the curve: 0.765 and 0.791, respectively).The Guy's grading system and STONE score were correlated with higher residual stone burden, especially in Guy's Grade IV cases.Conclusions: Stone burden and the number of affected calyces were the main predictors of success in USG-PCNL.Pre-operative evaluation tools can enhance patient selection and surgical planning, potentially optimizing clinical outcomes and reducing complications.