The normal left aortic arch courses from the ascending aorta to the left,
upwards and backwards in relation to the trachea. The aortic arch branches into the
right innominate, left common carotid and the left subclavian artery in sequence. The
aortic arch is divided into the proximal transverse arch and the distal transverse arch
and the aortic isthmus. Abnormalities of the aortic arch involve obstructive lesions, e.g.
coarctation of the aorta, and abnormalities of branching and position of the aortic arch
and the latter are topic of this article. Branching and position abnormalities of the aortic
arch have clinical meanings: mechanical compression of airway and esophagus by
forming a vascular ring or sling, association with cardiac abnormalities, and association
with chromosomal abnormalities. This chapter describes anatomical, genetical and
echocardiographic features as well as clinical postnatal implications of abnormalities of
branching and position of the aortic arch.
Keywords: Aortic arch, Echocardiography, Fetus, Prenatal diagnosis, Vascular ring.