[Ureteral obstruction secondary to iliac artery aneurysm]

A 65-year-old woman was seen in September, 1986, because of general malaise and dull pain in the left flank. Physical examination was unremarkable. Murmur was not heard over the abdomen. An excretory urogram showed left hydronephrosis and a retrograde pyelogram showed extrinsic obstruction at the level of the transverse process of the 5th lumbar spine. Computed tomography (CT) showed a mass with irregular calcification in its center. The mass was assumed to be located in the left iliac artery and as it was enhanced homogeneously, iliac aneurysm was suspected. Angiography revealed an aneurysm of the left iliac artery involving common, external and internal iliac arteries. The patient was treated by ligation of aneurysm, aorto-femoral graft bypass and ureterolysis. Histopathological findings showed aneurysm due to atherosclerosis. A postoperative excretory urogram showed improvement of hydronephrosis. Ureteral obstruction due to iliac aneurysm is unusual but it should be considered when performing differential diagnosis of extrinsic ureteral obstruction. CT is a useful diagnostic tool and aortography should be done to make a final diagnosis. Treatment is based on resection or ligation of aneurysm with ureterolysis.