The two common iliac arteries arise from the bifurcation of the abdominal aorta at the level of the fourth lumbar vertebra. Each runs approximately 5 cm inferolaterally before dividing into the external and internal iliac arteries at the sacroiliac joint level. The right common iliac artery is slightly longer than the left and crosses anterior to the left common iliac vein before dividing.
Common iliac artery aneurysms (CIAAs) are found in 20-30% of abdominal aortic aneurysm patients and must be measured during planning for endovascular aortic repair to determine seal zone adequacy. Occlusive disease at this level is a component of aortoiliac (Leriche) syndrome, producing bilateral claudication, buttock pain, and erectile dysfunction. The left common iliac vein is compressed beneath the right common iliac artery in May-Thurner syndrome, predisposing to left iliofemoral deep vein thrombosis.
Aneurysmal dilation exceeding 1.5 cm in diameter, usually associated with aortic aneurysm, often asymptomatic until rupture or thromboembolism occurs; repair is indicated at approximately 3 cm diameter or when symptomatic, with endovascular or open surgical options.
Bilateral aortoiliac occlusive disease producing the classic triad of bilateral claudication, absent femoral pulses, and erectile dysfunction from ischaemia of the internal iliac territories; treated with aortoiliac reconstruction or endovascular revascularisation.
