Hemitruncal sling: a newly recognized anomaly and its surgical correction.

A new type of vascular ring formed by a hemitruncal pulmonary artery is described. Early reimplantation of the hemitruncal pulmonary artery resulted in resolution of the respiratory distress, protection of the pulmonary arterial bed from obstructive vascular disease, and preparation of the pulmonary artery for future surgical correction.