The incidence of crossing vessels in patients with normal ureteropelvic junction examined with endoluminal ultrasound.

Abstract

We estimated the incidence of a crossing vessel at the normal ureteropelvic junction (UPJ) in patients undergoing ureteroscopy and endoluminal ultrasonography for indications other than UPJ obstruction. Endoluminal ultrasonography was performed in 141 patients undergoing upper tract endoscopy for various indications excluding UPJ obstruction. A detailed description of the anatomy of the UPJ as well as the location and size of crossing vessels was included in the operative note. Charts were reviewed to determine the precise anatomy of the UPJ. The overall incidence of crossing vessels at the unobstructed UPJ was 19.2%. Endoluminal ultrasonography demonstrated a crossing vessel in 13.2% of patients with ureteral narrowing or stricture, 31.3% of those with tumors or filling defects, 10.5% of those with submucosal calculi and 16.7% of patients with ureteral diverticula. In cases where the position of a crossing vessel was ascertained, 41% were anterior to the ureter, 28% anterolateral, 24% anteromedial and 7% posterior. There was a statistically significant difference in the frequency of vessels at the UPJ in patients with and without obstruction examined with endoluminal ultrasound (p <0.0001). A crossing vessel at the UPJ is seen with endoluminal ultrasound in 19.2% of patients with a normal UPJ. This incidence is lower than that seen in patients with obstructed UPJ. Many of these vessels are related to the lateral surface of the UPJ and there was no area that was always free of vessels.