A female patient aged 78 years with a huge aneurysm of the proximal left subclavian artery (Fig. 1) underwent surgery; after opening of the aneurysm, the entry was closed under circulatory arrest and a prosthetic bypass graft was placed between the ascending aorta and the left subclavian artery (Fig. 2).
Volume-rendered image of CT (computed tomographic) angiography shows a huge saccular aneurysm measuring 11 × 9 × 8.5 cm located at the origin of the left subclavian artery from the aortic arch. Such a huge aneurysm of the intrathoracic subclavian artery is rare. It also demonstrates the occlusion of the left common carotid artery and the left internal carotid artery. There is 75% stenosis of the left subclavian artery after the branching of the left vertebral artery and 50% stenosis of the right subclavian artery after the branching of the right vertebral artery. After the occurrence of left arteria cerebri media infarction 8 years before the operation, the patient had dysarthria and sensorimotor paralysis, which remained at the time of operation. Furthermore, the patient had progressive stridor due to the compression of the trachea by the aneurysm. In view of severe impairment of venous return due to the compression of the bilateral brachiocephalic veins, collateral venous pathways were identified in the chest wall. The aneurysm had enlarged progressively compared with its size 3 years before the operation (5.5 × 5.4 cm). An: aneurysm; BCA: brachiocephalic artery; LSCA: left subclavian artery.
Operative photographs of an aneurysm of the proximal left subclavian artery. (A) Under hypothermic low-flow cardiopulmonary bypass (16°C), the aneurysm was opened after ligation and transection of the occluded left common carotid artery. (B) After closure of the entry of the aneurysm with running sutures under circulatory arrest, a prosthetic bypass graft (woven double-velour vascular graft, 12 mm in diameter) was placed from the ascending aorta to the left subclavian artery at the exit of the aneurysm. Asterisk denotes the entry of the aneurysm. 
denotes the exit of the aneurysm. Black and white arrows indicate the cut-end of the left common carotid artery. An: cavity of the aneurysm; Ao: ascending aorta; PA: main pulmonary artery.
