Pulmonary artery sling

Pulmonary artery sling (PAS) is a rare congenital vascular anomaly where the left pulmonary artery (LPA) originates abnormally from the right pulmonary artery (RPA) instead of the main pulmonary artery. This aberrant course causes the LPA to pass between the trachea and esophagus. PAS caused by an embryological malformation and is frequently associated with other congenital anomalies, particularly affecting the airway and heart. Advanced imaging techniques such as CT, MRI, echocardiography, and bronchoscopy are essential for diagnosing PAS and identifying associated abnormalities. Surgical repair in early childhood is the standard treatment, aimed at relieving airway compression and correcting the other associated defects.

The term "vascular sling" comes from the configuration where the LPA compresses distal trachea and right mainstem bronchus as it courses between the trachea and esophagus to reach the left lung. This anomaly is classified as a type of vascular ring, though it does not form a complete ring around the airway and esophagus.

Pulmonary artery sling was originally written about in 1897 by Glaevecke and Doehle. The first known case PAS was diagnosed and surgically repaired in 1953 by Dr. Willis J. Potts at Lurie Children's Hospital (formerly Children's Memorial Hospital). He performed the procedure on a 5-month-old infant. Although the surgery was technically successful, follow-up imaging revealed limited blood flow to the left lung, highlighting the early challenges of managing this complex anomaly.