Risk stratification of composite adverse outcomes after percutaneous nephrolithotomy based on preoperative inflammatory-nutritional status and stone complexity: a single-center retrospective study.

OBJECTIVE

To investigate the predictive value of preoperative inflammatory-nutritional status and stone complexity for composite adverse outcomes following percutaneous nephrolithotomy (PCNL), and to develop a clinical risk stratification model.

METHODS

Clinical data of 386 patients with renal calculi who underwent PCNL at the Cangzhou Central Hospital between January 2021 and December 2024 were retrospectively analyzed. Composite adverse outcomes were defined as the occurrence of any of the following: postoperative fever (temperature >38 °C), systemic inflammatory response syndrome (SIRS), requirement for blood transfusion, or complications of Clavien-Dindo grade ≥ II. Preoperative inflammatory-nutritional status was assessed using the neutrophil-to-lymphocyte ratio (NLR) and prognostic nutritional index (PNI), while stone complexity was quantified using the Guy's grading system and the S. T. O. N. E. nephrolithometry score. Multivariate logistic regression analysis was performed to identify independent risk factors, and a risk stratification model was constructed based on the number of these factors.

RESULTS

Among the 386 patients, 121 (31.3%) experienced composite adverse outcomes postoperatively. Multivariate logistic regression analysis identified diabetes mellitus (OR = 2.41, 95% CI: 1.32-4.41, p = 0.004), preoperative urinary tract infection (OR = 3.27, 95% CI: 1.58-6.78, p = 0.001), NLR ≥ 3.5 (OR = 2.18, 95% CI: 1.35-3.52, p = 0.001), PNI < 45 (OR = 2.03, 95% CI: 1.22-3.38, p = 0.006), Guy's grade ≥ III (OR = 2.67, 95% CI: 1.56-4.56, p < 0.001), and S. T. O. N. E. score ≥8 (OR = 3.14, 95% CI: 1.89-5.22, p < 0.001) as independent risk factors for composite adverse outcomes after PCNL. Receiver operating characteristic (ROC) curve analysis indicated that ≥3 risk factors was the optimal cutoff for predicting composite adverse outcomes, with a sensitivity of 78.5%, specificity of 75.2%, and an area under the curve (AUC) of 0.837 (95% CI: 0.791-0.883). Patients were stratified into low-risk (0-2 factors), intermediate-risk (3-4 factors), and high-risk (≥5 factors) groups, with corresponding incidence rates of composite adverse outcomes of 12.5, 34.6, and 68.4%, respectively (p < 0.001).

CONCLUSION

Preoperative inflammatory-nutritional status (NLR, PNI) and stone complexity (Guy's grading system, S. T. O. N. E. score) are independent predictors of composite adverse outcomes after PCNL. The risk stratification model based on the number of risk factors is simple and reliable, and can effectively identify high-risk patients, providing a basis for precise perioperative management.