A baby with truncus arteriosus has one main heart artery instead of two. This congenital heart defect often occurs along with a ventricular septal defect (hole in the heart). Blood with and without oxygen mixes, making the heart work harder. Surgery during infancy can correct these problems. These children need more surgeries as they grow.
Truncus arteriosus (TRUN-kus are-teer-e-OH-sus) is a congenital heart defect (heart condition that’s present at birth). A baby with truncus arteriosus has one large artery (instead of the usual two arteries) for blood to flow in and out of the heart. These babies also have a single truncal valve instead of two valves to control this blood flow.
Truncus arteriosus is a life-threatening condition. It requires surgery shortly after birth.
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The heart and the arteries are part of the body’s circulatory system. A healthy heart should have a pulmonary artery (sends blue blood to the lungs) and an aorta (sends red blood to the body). A pulmonary valve and an aortic valve are two of the four valves that control blood flow through the heart.
Typically, blood flows from the right side of the heart through the pulmonary artery to the lungs to get oxygen. This oxygenated blood then flows to the left side of the heart and through the aorta to the rest of the body. Because a baby with truncus arteriosus only has one artery leading out of the heart, blood with and without oxygen mixes together.
Babies with truncus arteriosus also have ventricular septal defects (VSD). A VSD is a hole in the heart wall (septum) that separates the lower ventricles, or chambers, of the heart.
These two congenital heart defects allow too much blood to go into the lungs while not enough blood reaches the rest of the body. This forces the heart and lungs to work harder.
Truncus arteriosus is a rare birth defect (congenital disability). It occurs in approximately 1 in 10,000 births and affects baby boys and girls equally. Healthcare providers diagnose about 250 babies with this heart condition every year.
Other heart conditions associated with truncus arteriosus include:
In the uterus, all fetuses start with one large blood vessel (the truncus) that branches from the heart. As the fetus develops, the truncus divides into the pulmonary artery and aorta. When this split doesn’t happen, truncus arteriosus occurs. Not having the separation also leads to the VSD.
Experts are still trying to determine why some fetuses develop this type of congenital heart defect. It’s possible that certain gene changes play a role. About 1 in 3 children with truncus arteriosus also have a chromosomal disorder called DiGeorge syndrome. In addition to heart defects, this condition causes immune system problems and developmental delays.
A family history of congenital heart defects may increase the risk of a child having truncus arteriosus.
Certain factors that occur during pregnancy may also play a role. These include:
Newborns with truncus arteriosus often show signs of distress soon after birth because the heart is working too hard to pump blood.
Signs of truncus arteriosus include:
A prenatal ultrasound that takes place during pregnancy sometimes detects this heart defect. If an ultrasound indicates a potential problem, you may get a fetal echocardiogram. This type of ultrasound produces images of the fetal heart.
After your baby is born, a healthcare provider may use an echocardiogram to diagnose truncus arteriosus.
Untreated truncus arteriosus can lead to:
Babies with truncus arteriosus need heart surgery within the first weeks of life. There are several procedures to correct truncus arteriosus. The most common procedure is called a Rastelli repair. The surgery involves:
A newborn may also need:
Children with truncus arteriosus have a higher risk of developing a serious bacterial heart infection called endocarditis. Your child may need to take antibiotics before seeing the dentist or getting surgical procedures. Your child may need cardiac catheterizations (a procedure to look inside the heart) and repeat surgery to either address the truncal valve (new aortic valve) and/or the artificial tube used to make the new pulmonary artery.
Truncus arteriosus occurs for no known reason. There isn’t anything you can do to prevent it. For a healthy pregnancy, people should limit alcohol consumption (or not drink at all) and check with healthcare providers before taking medications.
After surgery, most children enjoy full, active lives. Your child may be able to play certain sports but should probably avoid high-impact activities. Talk to your healthcare provider about what activities are safe for your child.
Children with this heart condition need to see a heart specialist (pediatric cardiologist) for ongoing care. They will need to see a cardiologist throughout their life and will need to transition care to an adult congenital cardiologist around their 18th birthday. This doctor monitors your child’s heart health to quickly detect problems like leaky heart valves.
A child will need two to three surgeries to replace the artificial pulmonary artery with larger tubes as their heart and body grow. If the truncal valve thickens and becomes leaky, your child may get an artificial valve. Some people need another conduit and valve replacement procedure during adulthood.
Rarely, the artificial artery narrows or becomes blocked. Your child’s provider may perform a catheter-based procedure using a balloon device to open it up. Or the provider may place a stent (tiny tube) into the artery to keep it open.
You should call your healthcare provider if your child experiences:
You may want to ask your healthcare provider:
A note from Cleveland Clinic
Truncus arteriosus is a rare but serious congenital heart defect. It often occurs along with a ventricular septal defect or hole in the heart. These heart conditions allow blood with and without oxygen to mix. The heart must work harder to get oxygenated blood to the body. A baby with truncus arteriosus needs surgery soon after birth to correct the problem. Your child will need more heart surgeries as they grow. Most children with this heart defect live long, happy lives after surgical treatment.
Last reviewed by a Cleveland Clinic medical professional on 08/17/2021.
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