To analyze the risk factors associated with procedural failure in retrograde ureteral stenting (RUS) among patients with malignant extrinsic ureteral obstruction (MEUO), and to develop a predictive model for estimating the probability of procedural failure.

The data of 50 cases of procedural success and 50 cases of procedural failure in RUS were retrospectively collected from our hospital between 2020 and 2024. Eleven variables were recorded for each case, and univariate and multivariate logistic regression analyses were conducted to identify the optimal risk factors associated with RUS procedural failure. Based on these regression results, a nomogram was developed to calculate the failure probability. The discrimination ability of the nomogram was evaluated using receiver operating characteristic curve analysis, while an additional 20 cases of procedural success and 20 cases of procedural failure in RUS were included for validation.

Length of obstruction >3 cm, ureteral orifice violation, ureter invasion, and radiotherapy history were identified as the best predictors for RUS procedural failure. If the cumulative points calculated based on the nomogram exceeded 120, it indicated a substantial risk of RUS procedural failure. The nomogram was validated by the training set (Area Under Curve: 0.894) and the test set (Area Under Curve: 0.919), exhibiting exceptional predictive accuracy.

The nomogram developed in this study serves as a valuable and user-friendly tool for predicting the probability of RUS procedural failure among MEUO patients. It assists urologists and patients in choosing the optimal treatment for MEUO.