Introduction:
Pulmonary atresia is considered a birth defect. In babies with this condition, the blood flow to the lungs gets affected, resulting in difficulty picking up oxygen for the body. In this condition, the valve responsible for the blood flow from the heart to the lungs does not form correctly.
What Is Pulmonary Atresia?
Pulmonary atresia is a congenital heart defect. The heart has four chambers. When the heart squeezes, the right ventricle (the lower right pumping chamber) gets contracted, pushing the blood out to the lungs. The valve present in this chamber is called the pulmonary valve. This valve helps prevent the blood from leaking back into the heart chamber between the beats.
In this type of condition, the pulmonary valve is not formed properly. It may be sealed and cannot be opened. Many children exhibit ventricular septal defect (VSD). A VSD is a hole in between the lower chambers of the heart. When there is a combination of pulmonary atresia and VSD, it is called the tetralogy of Fallot with pulmonary atresia. In such cases, there may be a smaller-than-normal right ventricle or a defective tricuspid valve (valve) between the heart's upper and lower right chambers.
In this condition, the blood cannot flow from the heart to the lungs. Hence, oxygen cannot be supplied to the body. Pulmonary atresia is considered to be life-threatening, and it is estimated that it can affect one out of every 10,000 newborns.
What Are the Causes of Pulmonary Atresia?
The exact cause of pulmonary atresia is not known. It is thought to be caused by changes in genes or chromosomes, the combination of genes, and other factors. Other factors may include different things in the environment that come into contact with the mother, like what she eats, drinks, or uses a few medicines.
Pulmonary atresia may be seen among those with abnormal genes or chromosomal defects. Some children with Di George’s syndrome or velocardiofacial syndrome may exhibit a greater risk for pulmonary atresia.
What Are the Signs and Symptoms of Pulmonary Atresia?
Signs and symptoms of pulmonary atresia may be noticed immediately after the baby’s birth. Symptoms include,
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Cyanosis - a bluish tint to the skin, lips, and nails.
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Extreme weakness.
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The skin may be cool, pale, or clammy.
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Problems related to breathing.
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Problems related to feeding.
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Irritability may be observed.
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Heart murmur (heart sounds appear abnormal).
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Extreme sleepiness may be observed.
How to Diagnose Pulmonary Atresia?
The diagnosis of pulmonary atresia is usually done shortly after birth. However, before the birth of a child, some healthcare providers may do standard screening tests like ultrasound. If they suspect it, they may perform a fetal echocardiogram. This test makes use of sound waves to look at the fetal heart.
After the baby is born, healthcare providers check the heart with a stethoscope. If they find abnormal sounds in the heart, they may advise following tests.
These include,
Pulse Oximeter: This method is noninvasive and helps to know the amount of oxygen present in the baby’s blood.
Chest X-ray: This technique provides an image of the inside of the baby’s chest using painless X-rays.
Electrocardiogram: It is a non-invasive method that helps measure the heart's electrical activity. This also measures if any stress is present in the heart muscles.
Echocardiogram: It is a noninvasive imaging method that takes a moving picture of the heart and its valves. This technique uses harmless sound waves.
Cardiac Catheterization: This method is considered to be invasive. In this technique, a small, flexible tube is inserted into the blood vessel in the baby’s groin. Then this tube is moved through the heart. A contrast dye may be used to create a stronger image of the heart.
What Is the Treatment for Pulmonary Atresia?
The treatment of pulmonary atresia depends on its severity and how it affects the child’s general health, age, and medical history.
Treatment includes short-term treatments and surgeries.
Short-Term Treatments:
This includes medications and a balloon atrial septostomy.
Medications: An IV drug called Alprostadil is given to children with pulmonary atresia. This drug helps by preventing the ductus arteriosus that connects the aorta to the pulmonary artery. This prevents it from starting to close as it normally does within a few hours to days after birth. Keeping open the ductus arteriosus helps oxygen-poor blood flow from the baby’s aorta to the pulmonary artery. From the pulmonary artery, the blood reaches the lungs to pick up oxygen.
Balloon Atrial Septostomy: In this method, cardiac catheterization is used to enlarge the opening in the septum (the wall between the right and left atrium). This helps improve the blood flow to the lungs.
Surgeries:
The need for surgery depends on many factors, like
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The size of the right ventricle and
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The size of the pulmonary artery.
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The ability of the right ventricle to push the blood.
Surgery for Pulmonary Atresia With VSD: In this surgery, the VSD is closed, and the donated artery and valve are placed between the child’s right ventricle and pulmonary artery. This helps the blood flow from the right ventricle into the pulmonary artery and from there to the lungs.
Surgery for Pulmonary Atresia Without VSD: In this type of defect, the right ventricle is poorly developed. In such cases, there is a need for a series of three operations. These are to be performed within the first few years of life.
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The shunt or tube is placed directly from the aorta or one of its branches to the pulmonary artery in the first operation. This surgery ensures sufficient lung blood flow during the first few months of life.
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The second operation will be done between 4 and 8 months of age. This procedure is called the bidirectional Glenn or hemi-Fontan procedure. In this procedure, the shunt placed in the first operation is removed. After this, the superior vena cava is a major vein that carries deoxygenated blood from the upper part of the body to the heart, and the pulmonary artery is connected. This helps in allowing the blood to flow directly from the superior vena cava to the pulmonary artery. This, in turn, helps in the blood flow to the lungs.
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The third operation is done between 3 and 6 years of age. This procedure is known as the Fontan procedure. The inferior vena cava and the pulmonary artery are connected in this procedure.
What Are the Complications of Pulmonary Atresia?
The complications of pulmonary atresia include,
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After the operation, the baby has to remain in the hospital for one or two weeks and sometimes in the intensive care unit.
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There may be a requirement for a ventilator and heart monitor.
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It may pose feeding problems.
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Presence of delay in growth.
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Abnormal heart rhythms are observed.
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Heart failure may result.
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Liver disease may occur.
Complications should be monitored very closely, and some may need a heart transplant.
Pulmonary atresia may be fatal if no treatment is given. This happens due to low oxygen levels. Many surgeries are needed at different ages to manage the situation.
Conclusion:
Pulmonary atresia is a defect present from birth. In this condition, due to the defect in the formation of heart valves, there may be a low level of oxygen in the body. Hence, knowing about pulmonary atresia, its causes, symptoms, management, and complications becomes important. Knowing about the condition helps identify the problem early, and this, in turn, leads to effective treatment.
