The bovine aortic arch variant, frequently known as the bovine arch, is an abnormality in the aortic arch branching of the human heart. The variant is characterized by a deviation in the standard branching pattern, which normally involves separate origins for the three major branches: the brachiocephalic — or innominate — artery, the left common carotid artery, and the left subclavian artery. In the bovine arch variant, either the brachiocephalic artery and the left common carotid artery share an origin, or the left carotid artery is positioned as a branch of the brachiocephalic artery.
The name is an incorrect correlation to the anatomy of a true bovine heart, in which a single brachiocephaleic trunk branches into bilateral subclavian arteries and a bicarotid trunk. The configuration called the "bovine arch" in the human heart is actually rare among cattle. Although the source of the incorrect term is unknown, it persists as a common misnomer despite widespread awareness of the erroneous description among the medical community. Many professionals have suggested or adopted a variety of alternative naming standards for the condition.
Although this type of arch is one of the most common cardiac variants, it is still relatively rare in humans, with occurrences reported in 15% of patients observed in the medical community. Statistics show a higher rate of the aortic arch variant among Africans and African-Americans. In cardiac radiology, the arch is referred to as a normal variation on the common configuration. Although the variant is generally considered insignificant by the medical community, some experts have proposed a connection between the bovine arch and thoracic aortic aneurysm (TAA). Other studies have linked the condition with a possible predilection for blunt injury to the innominate artery, in which a higher occurrence of the condition was discovered during post-injury setting.
Currently there is no "cure" for the bovine arch variant, although theoretical possibilities for non-damaging corrective transplants and grafts have been proposed. The unusual configuration of the arch has led to some reported difficulties with aortic treatments, such as carotid artery stenting. This procedure uses non-invasive methods to treat blockages and other cardiac complications that could lead to strokes. The procedure utilizes a catheter to perform a non-surgical entry into the artery in an attempt to correct narrowed areas. Using transradial carotid artery stenting in cases of bovine arch anatomy allows access via either the left or right arm, depending on the method used.