Major aortopulmonary collateral artery
Major aortopulmonary collateral arteries are arteries that develop to supply blood to the lungs when native pulmonary circulation is underdeveloped. Instead of coming from the pulmonary trunk, supply develops from the aorta and other systemic arteries.
Pathogenesis and anatomy
Major aortopulmonary collateral arteries develop early in embryonic life but regress as the normal pulmonary arteries develop. In certain heart conditions the pulmonary arteries do not develop. The collaterals continue to grow, and can become the main supply of blood to the lungs. Though it is usually associated with congenital heart diseases with decreased pulmonary blood flow, like tetralogy of Fallot or pulmonary atresia, it may be seen sometimes in isolation. In the latter case, it is termed as isolated aortopulmonary collateral artery. In these cases, it may be one of the causes of congestive cardiac failure in neonates.The pulmonary arteries stem from the right side of the heart and usually carry deoxygenated blood from the body to the lungs. The collateral arteries carry blood which has already been oxygenated by the lungs, so they are of little use in helping the body to get oxygen.