Interruption of the aortic arch and coarctation of the aorta: pathogenetic relations.

The pathologic anatomic features and associated cardiac anomalies of 63 cases of interruption of the aortic arch (IAA) type A (54 reported and 9 observed) and 145 cases of type B (124 reported and 21 observed) were analyzed and compared with those seen in 57 autopsy cases of infant coarctation of the aorta (CA). There was no significant sex predominance within the 3 groups and the prognosis without surgery was uniformly poor. Ventricular septal defect was much more common in IAA type B than in type A or CA. Anomalous origin of the subclavian artery and DiGeorge syndrome were commonly associated with IAA type B but were rare in type A and CA. Transposition of the great arteries and double-inlet left ventricle are less common in IAA type B than in types A and CA. On the basis of these findings and the observation by Le Lièvre and Le Douarin that neural crest cells contribute significantly to the formation of the visceral arch system and associated organs, we postulate that IAA type B may be a manifestation of a developmental error involving the neural crest, as is the DiGeorge syndrome. We believe IAA type A and CA to be closely related anomalies that may be prenatally acquired and pathogenetically distinct from IAA type B.