Patent Ductus Arteriosus (aka PDA Ligation) | The ductus arteriosus does not close--a blood vessel that allows blood to go around the baby's lungs before birth. Soon after the infant is born and the lungs fill with air, the ductus arteriosus is no longer needed. PDA leads to abnormal blood flow between the aorta and pulmonary artery, two major blood vessels that carry blood from the heart.
