Headache & Pain
Headache attributed to disorder of homeostasis
Jul. 13, 2022
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Right subclavian steal with steno-occlusive disease of the innominate artery (pattern 1). Simplified schematic of the aortic arch and great vessels showing one possible collateral pathway to supply the right arm in the face of severe steno-occlusive disease of the innominate (brachiocephalic) artery (light green box). Flow is reversed in the right vertebral artery, and consequently blood is “stolen” from the vertebrobasilar circulation. Generally, this is compensated by increased antegrade flow in the left vertebral artery. Flow is reversed in the proximal right subclavian artery to supply the right common carotid artery. (Contributed and modified by Dr. Douglas Lanska. Greatly modified from original sketch in Owen E. A Manual of Anatomy for Senior Students. London and New York: Longmans, Green, and Co., 1890.)