Subclavian artery aneurysm: an unusual manifestation of Takayasu's arteritis.

Complications of Takayasu's arteritis are typically ischemic in nature because of progressive arterial narrowing, with aneurysm formation occurring as a late sequela. A 30-year-old Black woman with Takayasu's arteritis presented with a progressively enlarging and tender pulsatile mass at the base of the right neck. Upper extremity pulses were intact. Chest computed tomography and aortography demonstrated a 6-cm aneurysm of the right subclavian artery, which originated at the takeoff from the innominate artery, which was also ectatic. There was no evidence of occlusive disease. An operation was performed via the median sternotomy with transverse extension into the supraclavicular area. The distal innominate artery, proximal common carotid artery and entire subclavian artery were resected and replaced with a bifurcated stretch ePTFE graft. The aneurysm was without thrombus or atherosclerosis and all vessels were extremely thick-walled. Pathology revealed healed/healing nonspecific arteritis. Aneurysm formation is an unusual complication of Takayasu's arteritis. Previously reported sites of aneurysm formation include the thoracic and abdominal aorta, the innominate, carotid and superior mesenteric arteries, but not the subclavian artery. Of 28 patients enrolled in a recent clinical protocol at the National Institutes of Health with Takayasu's arteritis, none had aneurysm formation. The authors report surgical repair of a large aneurysm of the right subclavian artery in a young Black woman with Takayasu's arteritis.