Therapeutic considerations in congenital absence of the right pulmonary artery. Use of internal mammary artery as a preparatory shunt.

Congenital unilateral absence of a pulmonary artery is rare. When present, it is usually associated with other cardiac malformations. In this communication an infant with coarctation of the aorta, ventricular septal defect and absent right pulmonary artery is reported. After correction of the first two defects, due to persistent respiratory difficulty, the infant had exploration of the right pulmonary hilum in hopes of finding a pulmonary artery remnant and re-establishing blood flow to that lung. A small hilar vessel supplying all three lobes of the right lung was found and as a first stage, to enhance pulmonary arterial growth, a palliative systemic to pulmonary artery shunt was performed utilizing a large internal mammary artery. This is the first report of a case in which the internal mammary artery is used in an infant to establish systemic to pulmonary arterial flow in congenital unilateral absence of a pulmonary artery.