Importance of absent ductus arteriosus in tetralogy of Fallot with absent pulmonary valve syndrome.

Tetralogy of Fallot without pulmonary valve syndrome is almost always associated with an absent ductus arteriosus. Patients with right aortic arch and retroesophageal left subclavian artery have a vascular ring if the left ductus arteriosus or its remnant and the Kommerell diverticulum are present. We report the cases of 2 infants in whom the role of an absent ductus arteriosus or its remnant is noteworthy. Both patients had a combination of tetralogy of Fallot with absent pulmonary valve syndrome and right aortic arch with retroesophageal left subclavian artery without a vascular ring. The absence of the ductus arteriosus has a role in the pathogenesis of tetralogy of Fallot with absent pulmonary valve syndrome. The absence of a ductus arteriosus in the right aortic arch with retroesophageal left subclavian artery precludes a vascular ring.