Presentation
Confusion and headache. Past history of SAH secondary to ruptured MCA aneurysm complicated by vasospasm.
Patient Data
Incidental note of common origin of left common carotid and brachiocephalic trunk ('bovine arch') and thyroidea ima artery arising from the lateral aspect of the aortic arch, coursing between the left common carotid artery and left brachiocephalic vein to supply the inferior lobes of the thyroid.
Case Discussion
Aortic arch variants are common, occurring in ~30% of the population. Bovine arches are present in about 15% of the population. In the setting of potential neurointervention (e.g. for treatment of aneurysms or vasospasm) recognition of these are important because variant anatomy can complicate access to the carotid or vertebral arteries.