Prostaglandin E2 (PGE2) is known to be a potent endogenous vasodilator of the ductus arteriosus (DA), which is an essential bypass artery between the aorta and the main pulmonary artery. In some types of congenital heart diseases (CHDs) such as hypoplastic left heart syndrome or pulmonary atresia, blood flow through the DA is required for systemic or pulmonary circulation. Life-threatening conditions such as shock and severe acidosis would progress when the DA constricts a few hours to days after birth. Therefore, PGE1, a synthetic analog of PGE2, is widely used to maintain DA patency in neonates with ductus-dependent CHDs. Although there are considered to be no serious side effect of PGE1 for short-term use, fever and apnea are known to be common side effects. Administration of PGE1 is thought to be a palliative treatment before surgical intervention. However, in some cases, PGE1 might be continuously required for a longer duration. Therefore, long-term side effects of PGE1 should be taken into account.
The vessel characteristics of the DA are morphologically different from the adjacent arteries, which are the aorta and the main pulmonary artery. Physiological intimal thickness is well developed in the DA during a perinatal period. Elastic fibers in the medial walls are sparse and the internal elastic lamina is fragmented in the DA.