Chronic Ureteral Compression From a Thrombosed Iliac Artery Aneurysm: A Manifestation of Aortoiliac Aneurysmal Disease.

Ureteral obstruction caused by iliac artery aneurysms is uncommon and typically results from acute aneurysmal expansion or rupture. We describe a rare presentation in which chronic external compression from a large, thrombosed iliac artery aneurysm led to persistent left-sided hydronephrosis requiring serial ureteral stent exchanges in a 69-year-old male patient. The patient had an extensive vascular history, including prior aortoiliac aneurysm repair, and was not a candidate for further surgical intervention. Sequential CT imaging consistently demonstrated a stable, multilobulated thrombosed internal iliac artery aneurysm displacing the left ureter into a tortuous course. This case highlights an unusual mechanism of chronic ureteral obstruction and underscores the importance of recognizing vascular causes in patients with recurrent obstruction and complex vascular anatomy.