Ureteral Diameter as Predictor of Ureteral Injury during Ureteral Access Sheath Placement.

ABSTRACT

PURPOSE: We determined the association between ureteral diameter and ureteral injury during ureteral access sheath placement. MATERIALS AND METHODS: Patients were prospectively enrolled in the study from July 2014 to September 2015. All patients underwent preoperative noncontrast computerized tomography and had a 12Fr to 14Fr ureteral access sheath placement without pre-stenting. A measurement of proximal ureteral diameter was carried out by 2 urologists and 1 radiologist. Ureteral wall injuries were evaluated by 2 endourologists using the 5-grade classification. RESULTS: A total of 68 patients were included and the overall success rate for sheath placement was 94.1% (64). Among this group 46 patients (71.9%) had evidence of any type of injury to the ureter wall and the rate of high grade injuries was 26.1% (12). The ureteral diameter of patients who had a high grade injury was significantly smaller compared to those with low grade injuries (mean±SD 3.29±0.46 mm vs 4.5±0.97 mm, p <0.001). On multivariate analysis narrower proximal ureteral diameter was associated with a higher risk of high grade ureteral injury (OR 2.8, 95% CI 1.9-3.4, p <0.001), regardless of age, gender, body mass index, and middle and distal ureteral diameter. CONCLUSIONS: The proximal ureteral diameter is associated with high grade ureteral injury. A smaller ureteral diameter increases the risk and the severity of ureteral injury. Therefore, preoperative measurement of the ureteral diameter is recommended for ureteral access sheath placement to predict the risk of ureteral injury.