A dislodged mural thrombus from an abdominal aortic aneurysm most commonly affects which locations?

• A. Brain and heart
• B. Pelvis organs and lower extremities
• C. Lungs and liver
• D. Kidneys and spleen

Answer: (B)

Embolization from a mural thrombus in an abdominal aortic aneurysm travels downstream through the arterial circulation, so it tends to lodge in the first large distal vessels encountered after the aorta splits into the iliac arteries. The common iliac arteries feed the pelvis and, as the vessels continue into the internal and external iliac and then the femoral arteries, these end-arterial beds are the most frequent sites for emboli. Thus the pelvis organs and the lower extremities are the location most commonly affected. Emboli reaching the brain or heart would have to enter the carotid or coronary arteries, which is less typical for an aortic-origin thrombus, and pulmonary involvement is not a usual consequence of systemic arterial emboli. Kidney and spleen infarcts can occur but are less common than limb and pelvic involvement.