Development and Validation of a Predictive Model for Ureteral Stricture after Ureteroscopic Lithotripsy

Objective: To explore the risk factors of ureteral stricture after ureteroscopic lithotripsy, and to develop and validate a nomogram prediction model for rapid identification of high-risk patients and early intervention to reduce the probability of postoperative ureteral stricture.Methods: The clinical data of 379 patients with unilateral ureteral calculi who underwent ureteroscopy for the first time were retrospectively analyzed. Univariate and multivariate logistic regression analysis were used to analyze the correlation between factors and ureteral stricture. A predictive nomogram model was built based on the selected variables, and internal validation was completed in a random split manner. The area under the receiver operating characteristic curve and calibration curve were used to evaluate the discrimination and calibration. Decision curve analysis was used to test its clinical application value. Results: Twenty-four patients (6.33%) developed postoperative ureteral stricture. Logistic regression analysis showed that the time of onset, maximum transverse diameter of the stone, degree of renal pelvis separation, ureteral injury, operation time, and no preoperative reserved stent were the risk factors, and a nomogram model was constructed based on these influencing factors. The area under the receiver operating characteristic curve of the model was 0.914 (0.838-0.990), and the calibration curve showed that the model had good calibration. Decision curve analysis suggested that the model added net benefit to patients. Conclusions: The risk of postoperative ureteral stricture in patients undergoing URSL is affected by the time of onset, maximum transverse diameter of the stone, degree of pyelolysis, ureteral injury, operation time, and preoperative reserved stent. The nomogram prediction model based on the above factors has good predictive value.