Partial anomalous left pulmonary artery: new evidence on the development of the pulmonary artery sling.

Clinical and angiographic data of a child with a unique form of partial anomalous left pulmonary artery are reported. Because the anomalous pulmonary artery does not run posterior to the trachea, this malformation is not associated with airway obstruction, as are all other forms of anomalous left pulmonary artery described to date. This case strengthens our understanding of the development of the pulmonary artery sling.