A to Z: Pulmonary Artery Sling

May also be called: PAS, Aberrant Left Pulmonary Artery

Pulmonary artery (pul-muh-NAIR-ee AR-tuh-REE) sling is a rare condition children can be born with, in which the left pulmonary artery comes out of the right pulmonary artery and passes between the trachea (TRAY-kee-uh) and the esophagus (ih-SAH-fuh-gus) to reach the left lung.

More to Know

The pulmonary artery carries oxygen-poor blood from the right ventricle of the heart to the lungs. Normally, the pulmonary artery splits in two just after leaving the heart to form the right and left pulmonary arteries. Both arteries are supposed to pass in front of the trachea as they carry blood to the lungs. The trachea, or windpipe, is the main airway from the nose and mouth to the lungs.

When someone has a pulmonary artery sling (PAS), the left pulmonary artery comes out of the right pulmonary artery a short distance from the heart. To reach the left lung, the left pulmonary artery passes in between the trachea and the esophagus, which carries food and fluids from the mouth to the stomach. A pulmonary artery sling typically doesn’t cause any trouble with blood flow, but it can cause serious breathing problems as the artery pushes against the trachea. Sometimes children also have trouble feeding.

Severe cases of PAS can cause life-threatening problems in babies. Other children with PAS may have no issues and may only learn they have PAS when the condition is found by accident later in life. Treatment for PAS involves surgery to detach the left pulmonary artery from the right pulmonary artery and reattach it to the pulmonary artery stem in front of the trachea.

Keep in Mind

Cases of PAS that cause no problems may never need to be repaired. Severe cases may require open-heart surgery in the first months of life. Fortunately, if the condition is discovered and treated early enough, the long-term outlook for anyone born with a PAS is good.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.