Neonatal right lung emphysema due to pulmonary artery sling.

Pulmonary artery sling is a rare variant of vascular ring where the left pulmonary artery arises from the right and loops behind the trachea or right bronchus causing airway compression. A 40-day-old infant had been mechanically ventilated since birth for severe hypercapnia and right lung emphysema. Left pulmonary artery reimplantation was successfully performed.