Development and validation of a non-invasive nomogram for predicting proximal ureteral impacted calculi.

Objective: To develop and validate a prognostic nomogram for predicting the risk of proximal ureteral impacted calculi, supporting personalized clinical management.

Methods: This retrospective, multicenter study employed a continuous cohort of 391 patients with proximal ureteral stones treated between January 2021 and April 2024. Data from Longyan People's Hospital (affiliated with Xiamen Medical College) comprised the training set, while independent external validation was performed using data from The Fifth Affiliated Hospital of Fujian University of Traditional Chinese Medicine. Independent predictors were ascertained via univariate and multivariate logistic regression analysis. A nomogram was subsequently developed, and its predictive performance and clinical utility were evaluated.

Results: Hydronephrosis (OR = 3.911, 95% CI: 1.152-13.227, P = 0.044), maximum ureteral wall thickness (UWT) (OR = 9.574, 95% CI: 5.775-15.874, P < 0.001), maximum ureteral jet velocity (Vmax) (OR = 0.762, 95% CI: 0.677-0.858, P < 0.001), stone Hounsfield units (HU) (OR = 2.228, 95% CI: 1.207-4.114, P = 0.002), and stone size (OR = 2.069, 95% CI: 1.128-3.796, P = 0.019) emerged as significant independent predictors of impacted proximal ureteral calculi. The nomogram exhibited high predictive accuracy, with area under the receiver operating characteristic curve (AUC) values of 0.928 (training set) and 0.903 (validation set). Decision curve analysis indicated substantial net clinical benefit across a range of threshold probabilities for clinical use.

Conclusion: Hydronephrosis, UWT, Vmax, stone HU, and stone size constitute independent predictors of proximal ureteral impacted calculi. The nomogram incorporating these factors provides a reliable prognostic tool to assist in treatment planning and potentially enhance patient outcomes in clinical practice.