Insights into Arch Vessel Development in the Bovine Aortic Arch

A bovine arch is the most common aortic arch variant, characterized by a common origin of the innominate artery and the left common carotid artery. Data have shown that children with bovine arch anatomy and coarctation are at a significantly higher risk of recoarctation following coarctation repair. This study aims to explain the higher coarctation rates, assess the branching of the arch vessels, understand their embryologic origins, and delineate the patterns of displacement of the arch vessels in bovine versus normal anatomy. This retrospective study reviewed the medical records of 178 infants (< 1-year-old) who had a chest CT Angiogram (58) or CT (120) at our institution between 2007 and 2017. Multiplanar reconstruction software was used to obtain the best image plane to display the sinotubular junction, innominate artery, left common carotid artery, and left subclavian artery. We measured the distances between the branches as HV1, HV2, and HV3. All distances were standardized to body surface area and sinotubular junction diameter, which is a novel method. Bovine arches were found in 32.6% of patients. The total arch length of both arch anatomies was similar. HV3 is longer in bovine arches. HV1 + HV2 and HV2 + HV3 are longer in the normal arches than the bovine arches. The left subclavian artery moves proximally, and the innominate artery moves slightly distally to form the bovine arch and decreasing the clamping distance for coarctation repair. Aortic arch distances were similar when standardized to either sinotubular junction diameter and body surface area.