Vascular ring anomaly constricts the esophagus. This is a situation
in which the fetal blood vessels are still present when they should not
be. The most common form of this is a persistent right aortic arch, but
there are other possible ring anomalies. The vessel passes over the esophagus
and captures it between the persistent aortic arch and other structures,
constricting it. This can be cured surgically if many cases. In some cases,
the esophageal motility is permanent impaired and it is necessary to feed
liquid or semi-solid meals from a standing position for life.