Subclavian Steal and Vertebral Basilar Insufficiency

This 60-year-old smoker presented with several episodes of dizziness with intermittent brief loss of consciousness while waxing his car. He also reported left arm claudication with similar activities. He is a smoker and limits his activities because of leg discomfort while walking. He does not have coronary artery disease. This case demonstrates vertebral basilar insufficiency related to left subclavian artery steal phenomenon. This patient has complete occlusion of his left subclavian artery, which explains his arm claudication.There was flow reversal between the vertebral artery and the mid subclavian artery. Normally, the vertebral artery carries blood into the brain in an antegrade direction. In this case, because his subclavian artery is occluded, blood flow into the left arm is depends on reversal of blood flow from the posterior cerebral circulation into the arm itself. As a result, vertebral basilar insufficiency results as the metabolic and physiologic demands of the left arm require increased blood supply. To meet this demand, the subclavian artery steals blood from the brain via the vertebral artery system. This patient's contralateral vertebral artery is highly stenosed making him dependent on the left vertebral artery.

His problem was corrected by crossing the completely occluded left subclavian artery and deploying a stent to maintain its patency. At the beginning of the procedure, there was a 60-mmHg blood pressure difference between the upper left and right arms. This gradient was completely abolished after successful deployment of the stent.