What you should learn about Pulmonary Atresia?

Pulmonary Artery I

What is pulmonary atresia?

Pulmonary atresia is a birth defect of the heart in which the pulmonary valve that controls blood flow from the heart to the lungs does not form at all. In babies with this defect, no blood can flow from the right ventricle to the lungs. Because a baby with pulmonary atresia needs surgery soon after birth, this birth defect is considered a serious congenital heart disease.

In normal babies, the right heart carries oxygen-deprived blood from the heart to the lungs via the pulmonary artery. The oxygen-rich blood that flows back from the lungs to the left ventricle can then be pumped from the left ventricle to the rest of the body. In babies with pulmonary atresia, the pulmonary valve, which normally controls blood flow through the pulmonary artery, is not formed, so blood cannot travel directly from the right ventricle to the lungs.

In pulmonary atresia, because blood cannot flow directly from the right ventricle to the pulmonary artery, blood must bypass the unformed pulmonary valve using other routes. The foramen ovale, which usually closes after a baby is born, is a natural opening between the left and right chambers of the heart that usually stays open during fetal life to allow blood to flow to the lungs. In addition, your doctor may prescribe medication to keep your baby's ductus arteriae open after birth. The ductus arteriosus is an important channel that supplies blood to the lungs before a baby is born, and is usually closed after birth.

However, pulmonary atresia does not threaten the developing fetus because the mother's placenta provides the oxygen needed because the baby's lungs are not yet functioning; Once the baby is born, its lungs must now provide the oxygen it needs to survive, but the pulmonary artery is closed, preventing blood from the right ventricle from getting into the lungs. Because of this, cyanosis occurs in newborns. Pulmonary atresia can usually be diagnosed soon after birth.

Types of pulmonary atresia

There are usually two types of pulmonary atresia, depending on whether the baby has a concurrent ventricular deficiency.

1.Pulmonary atresia with intact interventricular septum: When the fetal heart is developing, very little blood flows in and out of the right ventricle, so the right ventricle is not fully developed and remains small. If the right ventricle is stunted, there is a problem with the heart pumping blood to the lungs. Also, the artery that carries blood out of the right ventricle is thin, because the pulmonary valve is not formed.

2. Pulmonary atresia with ventricular septal defect: In this form of pulmonary atresia, ventricular septal defect (VSD) allows blood to enter and exit the right ventricle (RV). Therefore, during pregnancy, the blood flowing into the right ventricle helps with the development of the ventricle, so it is usually not as small as when the interventricular septum is intact and the pulmonary artery is atresia. Pulmonary atresia with ventricular septal defect is similar to tetralogy of Fallot. However, in tetralogy of Fallot, pulmonary valve (PV) does indeed form, although it is small and blood cannot pass through it - this is called pulmonary valve stenosis. Therefore, pulmonary atresia with ventricular septal defect is like a very serious tetralogy of Fallot.

The treatment of pulmonary atresia

In some cases, blood flow can be improved by using a cardiac catheter. During this process, doctors can use balloons to dilate the valve, or they may need to place a stent to keep the arterial catheter open.

In most cases of pulmonary atresia, infants may require surgery shortly after birth. During surgery, doctors widen or replace the pulmonary artery valve to expand the passage to the pulmonary artery. If the baby has a ventricular septal defect, the doctor will also place a patch at the ventricular septal defect to close the hole between the two lower chambers of the heart. These actions will improve blood flow to the lungs and other parts of the body. If an infant with pulmonary atresia has right ventricular hypoplasia, he or she may need phased surgical treatment, similar to surgical repair of left ventricular hypoplasia syndrome.