A prospective study of endoluminal ultrasound versus computerized tomography angiography for detecting crossing vessels at the ureteropelvic junction

Purpose: Crossing vessels at the ureteropelvic junction are associated with bleeding complications and a higher risk of failure after endopyelotomy. We compared computerized tomography (CT) angiography and endoluminal ultrasound far detecting crossing vessels before planned endopyelotomy. Materials and Methods: Preoperatively patients underwent CT angiography. Intraoperative evaluation included retrograde ureteropyelography, endoluminal ultrasound and ureteroscopy, Intraoperative findings were used to direct treatment. Results: Endoluminal ultrasound detected 19 crossing vessels in 14 of 20 patients (70%), while CT detected 9 crossing vessels in 7 (35%). Endoluminal ultrasound identified a septum between the ureter and renal pelvis in 7 patients (35%) but CT demonstrated none. On the basis of imaging findings we selected 5 patients for pyeloplasty, and endoluminal ultrasound accurately predicted the absence or presence of crossing vessels in all 5. CT angiography was accurate in 3 patients. However, in 2 patients a total of 4 vessels were missed by CT. A total of 15 patients underwent endopyelotomy with no bleeding complications. The presence or absence of a septum on endoluminal ultrasound was confirmed in all patients. Imaging findings altered the treatment chosen in 4 patients and changed the direction of the incision at the ureteropelvic junction in another 4. Clinical and radiographic success was achieved in all 13 patients (100%) with adequate followup. Conclusions: Endoluminal ultrasound was more sensitive than CT angiography for identifying crossing vessels and septa. Treatment based an endoluminal ultrasound findings may decrease complications and improve the results of minimally invasive treatment for ureteropelvic junction obstruction.