Pulmonary Atresia: Causes, Symptoms, Treatment, Surgery, Diagnosis

Pulmonary Atresia is the name given to a potentially serious congenital heart defect that normally develops within the first trimester of the pregnancy in the fetus. In this condition, there is abnormal development of the pulmonary valve of the heart. The pulmonary valve is found between the right ventricle and the pulmonary artery. The function of the pulmonary valve is to carry deoxygenated blood to the lungs where it gets oxygenated and goes back to the heart from where it is pumped to the rest of the body in order for the organs to carry out their functions.

The pulmonary valve works as a one way door where the blood goes to the lungs through the pulmonary artery, but cannot go back to the pulmonary valve. What happens in Pulmonary Atresia is that there is an abnormality in the opening of the pulmonary valve such that blood is not able to pass through this valve and go the lungs to get oxygenated.

In majority of the cases if a child has Pulmonary Atresia, there is always an opening in the ventricular wall. This opening is called as ventriculoseptal defect. The blood escapes through this opening and is pumped to the rest of the body.

Another way through which this blocked blood goes out of the pulmonary valve is through a hole between the left and right atria. These are two ways through which blood makes it out through the pulmonary valve and is inadvertently pumped to the rest of the body. Since the blood that is pumped to the body is devoid of any oxygen since it is not able to reach the lungs it does not allow the other organs to function normally due to lack of oxygen resulting in the many vital organs malfunctioning due to Pulmonary Atresia.

In some cases, there is a connection between the aorta and the pulmonary artery known as ductus arteriosus, which allows some blood to pass through it and get to the lungs to get oxygenated. This ductus arteriosus unfortunately closes within a few hours or days after birth. As a result of the low oxygen within the body, most babies with Pulmonary Atresia are born with a bluish discoloration of the skin pointing towards a heart defect and with further investigation getting a diagnosis of Pulmonary Atresia.

As stated, Pulmonary Atresia develops within the first trimester of pregnancy meaning that the defect develops within the first 8 to 10 weeks of fetal development. The exact cause of this condition is not known, but some studies suggest a genetic link to the development of Pulmonary Atresia. In majority of the cases, there is no cause found for the development of Pulmonary Atresia.

In most of the cases of Pulmonary Atresia, the symptoms are evident soon after the delivery of the child with a bluish skin discoloration indicating that there is not enough oxygen within the body. In some cases, it may take a few hours to a few days for the symptoms to become evident of Pulmonary Atresia.

Some of the symptoms of this condition include:

• Bluish discoloration of the skin.
• Rapid breathing or shortness of breath.
• Easy fatiguing.
• Problems with feeding.
• Sweating while feeding.
• A clammy skin which feels cool to touch.

As soon as the symptoms classic for Pulmonary Atresia present, the physician may order a series of tests to confirm the diagnosis of Pulmonary Atresia. These tests include:

X-ray: An x-ray of the chest will clearly show an abnormality within the pulmonary valve indicating towards a diagnosis of Pulmonary Atresia.

Electrocardiogram: This is a test which checks whether the heart is functioning normally or not. This test will clearly show an abnormality in which the heart’s function point towards a cardiac condition causing the symptoms.

Echocardiogram: This test uses sound waves to get detailed images of the heart which makes it easier for the physician to identify any abnormality. This test will clearly show a defect in the pulmonary valve confirming the diagnosis of Pulmonary Atresia. In cases where there is a family history of Pulmonary Atresia, then a fetal echocardiogram of the abdomen can be performed to check whether the fetus has this heart defect or not.

Cardiac Catheterization: This is yet another way to diagnose Pulmonary Atresia. In this test, a thin flexible tube with a minature camera in it is inserted through the groin into the heart to get detailed information about any defects present in the heart. This test also confirms the diagnosis of Pulmonary Atresia.

Pulmonary Atresia is an emergent medical condition that requires immediate treatment. The front line treatment for Pulmonary Atresia is surgery to correct the defect.

Initially, prior to surgery medications like prostaglandin may be given which prevents the closure of ductus arteriosus so that at least some oxygenated blood flows through the body till the time a permanent fix in the form of which surgery to perform is formulated by the physician. There are two ways through which Pulmonary Atresia can be treated either with catheterization or proper surgical procedures.

Some of the ways to treat Pulmonary Atresia through the catheterization technique are:

Radiofrequency Ablation with Balloon Valvotomy: This procedure is basically done in those patients who have fused cusps of the valves which do not allow the valve to open up. In this procedure, radiofrequency ablation is used to create a hole in the center of the valve and then a balloon is used to open up the fused cusps of the valve so that the valve is opened and blood is able to flow through it to the lungs smoothly.

Balloon Atrial Septostomy: A small amount of blood escapes through the foramen ovale and gets oxygenated in cases of Pulmonary Atresia. This hole usually closes soon after birth. In this procedure a balloon is used to widen the hole which allows more blood to flow through it and get oxygenated.

Stents: In this procedure, a stent may be placed within the ductus arteriosus to prevent it from closing such that more blood is allowed to travel through it to the lungs to get oxygenated.

These above procedures may be successful in treating cases of Pulmonary Atresia but a heart surgery is basically a permanent fix for this condition. Some of the surgical procedures done for treatment of Pulmonary Atresia are:

Shunting: In this procedure, a bypass is created from the aorta to the pulmonary artery through which blood passes easily and goes to the lungs to get oxygenated. However, the downside of this procedure is that babies outgrow this shunt within a short span of time and the symptoms start to appear again of Pulmonary Atresia.

Fontan Procedure: This is a procedure that is done in cases where the pulmonary valve is way too small to be repaired. In this procedure, a separate path is created for the blood to flow directly from the heart to the pulmonary artery from where they go to the lungs and gets oxygenated. This is yet another successful way of treating children with Pulmonary Atresia.

Heart Transplant: This is the last resort and done in cases where the heart is far too damaged to repair and is done to save the child from complications of Pulmonary Atresia.