Left carotid steal. A new observation.

A patient had an occlusion of the left subclavian artery just proximal to the takeoff of a previously placed subclavian-carotid graft. This caused reversal of flow in the graft and a symptomatic steal of blood via to the intracranial arteries. An axilloaxillary graft restored forward flow. In a second patient, a steal occurred from the right carotid and vertebral systems into the distal carotid system of the left side that has been isolated by a proximal carotide artery occlusion from arteriosclerosis. A saphenous vein, used as a bypass from the subclavian to the carotid artery, restored normal flow. Thus, the carotide system may be the low-pressure area responsible for the steal, although this is rarer than the subclavian.