Examining the obstructed ureter with intraluminal sonography.

PURPOSE: Intraluminal sonography was used to define, differentiate and direct better treatment of obstructing ureteral lesions.

MATERIALS AND METHODS: A total of 63 patients with a history of ureteral obstruction and suspected stricture were accrued for evaluation. All patients underwent retrograde contrast imaging, ureteroscopy and intraluminal sonography as part of a diagnostic algorithm. Specific sonographic criteria to differentiate lesions and stricture types were developed. Associated complicating variables defined on sonography included foreign bodies, submucosal stone fragments, ureteral wall fibrosis, mass lesions and adjacent vasculature. Endoscopic treatment was then performed with ultrasound guidance if technically feasible.

RESULTS: A total of 63 ureters were evaluated with the preoperative diagnosis of ureteral stricture disease. All ureters were narrowed on contrast imaging in the segment where a stricture was suspected. On sonography 24 ureters (36%) had wall fibrosis with normal periureteral tissues. In general these strictures did well with endoscopic incision. Of the 67 ureters 13 (19%) were thickened or had edematous walls with normal architecture and without fibrosis. These patients all did well with expectant therapy. In contrast, 7 ureters (10%) were obstructed by segmental retroperitoneal fibrosis which did not respond to minimally invasive therapies. In addition, 8 ureters (12%) were obstructed by ureteral wall scarring and periureteral fibrosis, and required open surgical intervention. Ten ureteral strictures had adjacent vasculature, and endoscopic incisions under ultrasound guidance were directed safely away from these structures without associated morbidity. Calculi, stone fragments and foreign bodies embedded in the ureteral wall with associated inflammation were defined with sonography and responded to endoscopic therapies. The intraluminal sonographic diagnosis of ureteral endometriosis was made in 6 patients with a range of lesions from bright, hyperechoic blood filled cysts to an inhomogeneous fluid filled scar involving the wall and periureteral tissues. Primary ureteral carcinoma was also demonstrated in 2 patients after other diagnostic techniques failed. In 1 of these patients intraluminal sonography directed biopsies diagnosed submucosal tumor. Finally, 1 patient had a small periureteral urinoma on intraluminal sonography which was missed on other imaging studies.

CONCLUSIONS: Intraluminal sonography is useful in patients with ureteral obstruction of unclear etiology as well as for selecting patients who may benefit from minimally invasive therapies and safely directing these treatments.