The two arches surround the esophagus and trachea which, if sufficiently constrictive, may cause breathing or swallowing difficulties despite medical therapies. A less common<unk>  is present with a right aortic arch instead of the usual left-sided aortic arch. This compresses the esophagus and trachea because of the persistence of a ductal ligament (from fetal circulation) that may connect between the aorta on the front and the left subclavian artery posteriorly going to the left arm.
Vascular ring
Omphalolith
Persistent cloaca
Vascular malformation
Skin tag
Rachischisis
Bone malrotation
Omphalocele