Pulmonary atresia

Pulmonary atresia with ventricular septal defect

Pulmonary atresia (uh-TREE-zhuh) with ventricular septal defect (VSD) is a heart problem present at birth (congenital heart defect).

In this pulmonary atresia, the valve between the heart and lungs (pulmonary valve) is not fully developed. Blood can't flow from the right lower heart chamber (right ventricle) to the lungs. In pulmonary atresia with ventricular septal defect (VSD), there's also a hole between the two pumping chambers of the heart.

The VSD allows blood to flow into and out of the baby's right ventricle. Some blood may also flow through a natural opening called the ductus arteriosis. The ductus arteriosus typically closes soon after birth, but it can be kept open with medications.

The lung artery and its branches can be very small or nonexistent in babies with pulmonary atresia. If these blood vessels are missing, other arteries form on the body's main artery (aorta) to provide blood flow to the lungs. These arteries are called major aortopulmonary collateral arteries (MAPCAs).

Pulmonary atresia with ventricular septal defect is a life-threatening condition. A baby with pulmonary atresia doesn't get enough oxygen. Medications and one or more procedures or surgeries are needed to help the heart work better and repair the congenital heart defects.

Diagnosis

Pulmonary atresia with ventricular septal defect is typically diagnosed at birth or soon after. Tests that may be used to diagnose pulmonary atresia with ventricular septal defect include:

• Pulse oximetry. A small sensor attached to a hand or foot measures the amount of oxygen in the blood. Pulse oximetry is simple and painless.
• Chest X-ray. A chest X-ray shows the shape and size of the heart and lungs.
• Echocardiogram. Sound waves are used to create images of the beating heart. An echocardiogram of the mother's belly before delivery (fetal echocardiogram) can be used to diagnose pulmonary atresia.
• Electrocardiogram (ECG or EKG). This quick and simple test measures the electrical activity of the heart. Sticky patches (electrodes) with sensors detect the heartbeat. A monitor connected to the wires prints or displays results. An ECG can show how fast or slow the heart is beating. It can help diagnose irregular heart rhythms (arrhythmias).
• Cardiac catheterization. A heart doctor (cardiologist) threads a thin tube (catheter) through a blood vessel in the arm or groin to an artery in the heart and injects dye through the catheter. This makes the heart arteries show up more clearly on an X-ray.
• Cardiac CT scan. This test uses a series of X-rays to create pictures of the heart and blood vessels. It can help reveal the shape of the heart and lungs and determine if major aortopulmonary collateral arteries (MAPCAs) are present. Knowing about the MAPCAs is important for planning treatment.

Treatment

Babies with pulmonary atresia with ventricular septal defect need immediate treatment. Treatment may include medications and one or more surgeries or procedures.

Surgeries or other procedures

A baby with pulmonary atresia with ventricular septal defect (VSD) typically needs one or more surgeries or procedures to improve blood flow and heart function. Treatment depends on the structure of the pulmonary arteries and whether or not there are major aortopulmonary collateral arteries (MAPCAs).

Surgeries or other procedures to treat pulmonary atresia with ventricular septal defect may include:

• Catheter procedures for the pulmonary artery branches. This procedure is done to look at the baby's heart and possibly reconstruct the blood vessels coming off the pulmonary artery. A balloon on the tip of the catheter may be used to widen any narrowed areas. A rigid tube (stent) may be placed in a vessel between the aorta and pulmonary artery (ductus arteriosus) to keep it open and let blood flow into the lungs.
• Systemic-to-pulmonary artery shunt. This surgery may be needed in the first few days of life to increase blood flow to the lungs. It creates a connection (shunt) for blood to flow using a small synthetic tube. An example is the Blalock-Taussig shunt (BT shunt).
• Neonatal complete repair. If a baby's heart has well-developed pulmonary arteries and no MAPCAs, a surgeon can perform a complete repair at one time during the first 4 weeks of life. During the complete repair surgery, the ventricular septal defect is closed and a tube with an artificial valve is placed between the right lower heart chamber (ventricle) and the pulmonary artery.
• One-stage complete repair. Also called unifocalization, this procedure is done to connect all the MAPCAs together to create new pulmonary arteries. The surgeon then completes the repair with closure of the VSD. A tube graft (with or without a valve) is used to make a connection between the right lower heart chamber and the pulmonary artery. This procedure is usually done between 4 and 6 months of age.
• Staged unifocalization. If the MAPCAs are small or have multiple areas of narrowing, surgery to connect them may be done in stages. This allows the arteries to grow before the complete repair. A small shunt from the aorta to the newly created pulmonary arteries allows the blood to flow to the lungs. After a few months, cardiac imaging tests are done to determine whether the baby is ready for the complete repair.

Babies with pulmonary atresia with ventricular septal defect (VSD) need regular checkups by a cardiologist with training in pediatric congenital heart disease.