Abdominal aortic aneurysm with inferior vena cava compression in association with deep venous thrombosis.

Deep venous thrombosis (DVT) of the lower extremity may be caused by external compression of the inferior vena cava (IVC) by a neighboring mass. A 55-year-old male presented with 8 months of intermittent left lower extremity swelling and signs of chronic venous stasis. Duplex ultrasound showed extensive DVT in the left leg. Subsequent imaging revealed a 4.2 cm infrarenal abdominal aortic aneurysm (AAA) compressing the IVC. In cases of chronic, unilateral DVT, work-up should include imaging for an anatomic cause. AAA is a rare cause of IVC compression with DVT, and is most commonly related to inflammatory AAAs. Previously reported cases of IVC compression by non-inflammatory AAAs have been secondary to large aneurysms (greater than 6 cm). This case illustrates that smaller AAAs lacking hemodynamically significant IVC obstruction may be found in association with DVT.