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 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 had been isolated by a proximal carotid artery occlusion from arteriosclerosis. A saphenous vein, used as a bypass from the subclavian to the carotid artery, restored normal flow. Thus, the carotid system may be the low-pressure area responsible for the steal, although this is rarer than the subclavian.
Shumacker HB, Isch JH. Left Carotid StealA New Observation. Arch Surg. 1975;110(4):399-401. doi:10.1001/archsurg.1975.01360100041008