Visible Human anatomy helps one become more familiar with normal anatomic relations. It can be helpful when coming across unexpected anatomical varients. This featured movie involves a patient who was evaluated by EUS for chest masses which were lying against the aorta. Review of her CT scan suggested that this patient had a vascular anatomic variant consisting of a right sided aorta, and a right sided aortic arch. The right carotid artery and the right subclavian artery arose directly off the arch. The left carotid artery arose from the ascending part of the aortic arch and wrapped around the esophagus anteriorly, while the left subclavian artery arose from the descending aorta posteriorly, wrapping the esophagus in a vascular ring. The patient had no symptoms from this, although the term dysphagia lusoria can be applied to swallowing problems which occur from a vascular ring. The abnormal anatomy did not prevent successful biopsy and further staging by EUS.

Right sided aortic arch with aberrant subclavian artery was recently described to occur approximately 1 in 300 exams in a pediatric echocardiography database.¹ Suggesting it is unusual but should be seen in a busy EUS practice. Familiarity with the normal anatomic features helps when one is faced with these type of unusual cases.

The movie shows models of the normal aortic arch, then selected images of trans axial cross sections. This is followed by some selected CT images and radial array EUS features of this vascular process.

References:

1. Ramaswamy P, Lytrivi ID, Thanjan MT, Nguyen T, Srivastava S, Sharma S, Ko HH, Parness IA, Lai WW. Frequency of aberrant subclavian artery, arch laterality, and associated intracardiac anomalies detected by echocardiography. Am J Cardiol. 2008 Mar 1;101(5):677-82. <Related link>