Pulmonary artery sling.

Pulmonary artery sling is a rare cause of respiratory distress the embryological origin of which is not known. Two patients with this abnormality, both of whom are now thriving, are described. Surgery was necessary at the age of 5 1/2 years in one child, who also had an atrial septal defect. The other child, at the age of 2 years, shows improvement of her wheezing, cough, and breathlessness despite having had neither surgical nor medical treatment.