Over a dozen different aortic arch great vessel configurations have been described in humans. I’ve illustrated the two most common types in this diagram. The “normal” aortic arch gives rise to three “great vessels.” From proximal to distal, these arteries are the innominate (which, in turn, gives rise to the right common carotid, RCC, and the right subclavian, RSA), the left common carotid (LCC), and the left subclavian (LSA).
In the second most common configuration, the LCC arises from the innominate artery. This latter configuration is often incorrectly labeled as a “bovine arch.” In reality, a TRUE bovine arch (ie, what’s actually found in cattle) has a single vessel from the aortic arch which gives rise to the innominate artery, LCC, and LSA. These bovine variations typically have no clinical significance, but they are sometimes associated with aortic dissection, embolic phenomena, and other cardiovascular abnormalities.
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