Is there any predictive value of the ratio of the upper to the lower diameter of the ureter for ureteral stone impaction?

We aimed to determine if the ratio of the upper to the lower diameter of the ureter could have any predictive value for ureteral stone impaction. Patients who had a solitary unilateral ureteric stone, determined by noncontrast computerized tomography, were assessed if they had undergone ureteroscopic lithotripsy. A total of 111 patients, 84 males (76%), and 27 females (24%), were recruited to the study. Demographic data of the patients and preoperative radiological parameters based on noncontrast computerized tomography were recorded. The impaction status was also assessed during the operation. Of the 111 patients, ureteral stones in 63 (57%) patients were determined to be impacted, and ureteral stones in 48 (43%) were nonimpacted. Impacted stones were more common in older patients, female patients, and patients with an American Society of Anesthesiologists score of 2. Significant relationships were found between the impaction status and transverse stone length, longest stone length, upper diameter of the ureter, ratio (upper diameter of the ureter/lower diameter of the ureter), and anteroposterior diameter of the pelvis. These parameters were higher in patients with impacted stones.