Adachi-Williams type CG plus type H aortic arch anomaly and implications for development of cervicothoracic...

It is unclear whether the development of the branches of the subclavian artery is dependent on the proximal part of this artery, since great vessel formation is partly regulated by haemodynamic stress. For example, the vertebral artery that usually arises from the subclavian artery might be affected by anomalies in the aortic arch branches. This uncertainty is partly due to the limited reports of highly anomalous cases of proximal and distal branching morphologies. Here, we report the case of an Adachi-Williams type CG plus H aortic arch found during dissection, and discuss the development of the cervicothoracic circulation.

We report an aberrant right subclavian artery that arose from the aorta distal to the left subclavian artery, via a retroesophageal course, whereas the right and left common carotid arteries arose from a short common trunk from the aorta (the carotid trunk) (Adachi-Williams type H). In addition, the left vertebral artery arose directly from the aortic arch between the carotid trunk and the left subclavian artery (Adachi-Williams type CG). Anomalies in the branching arteries from this aberrant right subclavian artery (the right vertebral artery, internal thoracic artery, thyrocervical trunk, costocervical trunk and thoracoacromial artery) were unidentifiable. The right vagus nerve directly innervates the laryngeal muscles without forming the recurrent nerve.

The development of an aberrant right subclavian artery might affect haemodynamic stress in both the proximal and distal regions of the anterior limb region. The distal branching morphology, however, was normal, suggesting independence from proximal and distal vasculature development. Since the concomitance of Adachi-Williams types CG and H is rare, rather than sequentially develop, the distal arteries develop in a fine-tuned manner to adapt to anomalies in the proximal arteries.