Anomalous origin of left pulmonary artery from aorta with tetralogy of Fallot in an adult: what is protecting the lung?

Anomalous origin of one-branch pulmonary artery from aorta (AOPA) is a rare congenital anomaly. Uncorrected, it leads to rapid and frequently irreversible pulmonary hypertension. Association with tetralogy of Fallot is very rare and poses a problem of variable pulmonary vascular resistance. Surgical correction involves closure of ventricular septal defect, relief of right ventricular outflow obstruction, and reconstruction of the pulmonary confluence. The AOPA lung appears to be protected from irreversible vascular changes even in adulthood by unknown mechanisms.