Ureteral wall thickness at the ureterovesical junction as a significant factor in predicting medical expulsive therapy of ureterovesical junction stones.

Background: To evaluate ureteral wall thickness (UWT) at the ureterovesical junction (UVJ) measured by ultrasound for predicting spontaneous passage (SP) of uncomplicated UVJ stones.

Patients and methods: We retrospectively reviewed 170 patients ≥ 18 years old, and size ≤ 10 mm of single UVJ stone, who were examined and treated in the Third People's Hospital of Yunnan Province from January 2020 to January 2024. The analysis included the size of the stones, the maximum UWT at the stone site measured by ultrasound, the degree of hydronephrosis, and the time of stone removal.According to the different results after four weeks of medical expulsive therapy (MET), the patients were separated into two categories: Stone-passing group (SPG) and non-stone-passing group (NSPG). Univariate and multivariate logistic regression analysis were utilised to evaluate the clinical predictors of MET.The receiver operating characteristic (ROC) curve was employed to evaluate the accuracy of the UWT at the UVJ in predicting successful MET.

Results: The SPG comprised 112 cases (65.9%), while the NSPG consisted of 58 cases (34.2%). Univariate analysis, employing both the chi-square test and the Mann-Whitney U test, revealed that gender, age, stone side and degree of hydronephrosis were not statistically significant. However, stone size and UWT were found to be influencing factors in regard to stone removal. Binary logistic regression analysis demonstrated that UWT and size were independent influencing factor of MET. The ROC analysis indicated that 3.705 mm was the ideal threshold for UWT, with sensitivity and specificity levels of 72.4% and 68.7%, with an area under the ROC curve (AUC) of 0.737.

Conclusions: The UWT at the UVJ has a high predictive value for the MET of stones at this position, thus avoiding the adverse consequences of delayed stone discharge caused by unnecessary surgical operation and MET.