Localised thrombus in the distal aortic arch: its aetiology analysed by three-dimensional mould model of the thoracic aorta.

Isolated thrombus of the thoracic aorta without aneurysmal change or dissection is a relatively rare event. A case presenting with aortic thrombus and successive distal embolism is reported herein and the aetiology of the thrombus of the distal aortic arch is analysed by a three dimensional aortic model. A 61-year-old man suffered acute ischaemia in his right leg on January 26, 1994. Enhanced computed tomography (CT) showed a localized thrombus in the distal aortic arch expanding towards the descending aorta, and partial infarction of the left kidney and the spleen. Angiography demonstrated abrupt occlusion of the right superficial femoral artery. Immediate anticoagulation with heparin and coumadin was administered, and the thrombus in the aorta disappeared following 1 month of this medical treatment, leaving the renal and splenic infarction unchanged. The unresolved occlusion of the superficial femoral artery and the popliteal artery was treated with a bypass from the right superficial femoral artery to the peroneal artery using a reversed saphenous vein graft. The mould model of the thoracic aorta was reconstructed from CT, and the thrombus was found to be at the most distal and medial site of the lesser curvature of the aortic arch. This specific location is referred mostly as the site for thrombus formation in the literature. The case is reported briefly and the risk of this specific region of the thoracic aorta for thrombus formation is discussed using this mold model.