Endopyelotomy: importance of crossing vessels demonstrated by endoluminal ultrasonography.

Endoscopic incision has become a common treatment for ureteropelvic junction (UPJ) obstruction. Recent reports have indicated the importance of crossing vessels in the success of endopyelotomy. Endoluminal ultrasound can define the location and size of adjacent vessels, and the effect of these vessels and their location on the success of endopyelotomy can be determined. A group of 28 patients found to have UPJ obstruction on excretory urography, retrograde ureteropyelography, radiographic nuclear scan, and clinical presentation were evaluated by endoluminal ultrasound at the time of endopyelotomy, which was performed by percutaneous nephroscopy or retrograde ureteroscopy. All patients had an indwelling ureteral stent postoperatively. Follow-up evaluation included renal ultrasound and nuclear scans. Excretory urography was performed in several patients. In this preliminary study, the success rate was lower in patients with vessels in a lateral position at the UPJ. The endoscopic approach did not alter the success rate. These factors should be considered in treating primary UPJ obstruction with endoluminal incision.