Abnormal development of fourth aortic arch derivatives in the pathogenesis of tetralogy of Fallot.

Aortic arch (AoA) anomalies were studied in 233 patients with tetralogy of Fallot (TOF) of whom some had coexisting pulmonary atresia (PA). There was a 23% incidence of a right AoA in patients without PA, 21% in those with both PA and persistent ductus arteriosus (PDA), and 50% in those with PA and major aortopulmonary collateral arteries (MAPCAs). There was a 5% incidence of an aberrant subclavian artery in patients without PA and a 16% incidence in those with PA and MAPCAs. In this cohort an elongated ascending aorta was observed both with and without high aortic arch. These aortic arch anomalies were frequently associated with PA and MAPCAs.