Children's Hospital Colorado

Truncus Arteriosus

What is truncus arteriosus?

Truncus arteriosus is a rare type of congenital birth defect in which the two major arteries of the heart (the aorta and the pulmonary artery) fail to separate during development. Instead, there is only one large vessel coming from the heart.

The valve arising from the single blood vessel, called the truncal valve, is often abnormal. The valve can be thickened and narrowed which can block the blood as it leaves the heart. The truncal valve can also leak, causing blood that leaves the heart to leak back into the heart across the valve.

The large artery, known as the truncus arteriosus, has one valve that carries blood from both ventricles. Almost every child with this heart condition will also have a hole between the ventricles, known as a ventricular septal defect (VSD). This condition results in too much blood going to the lungs and can result in irreversible damage to the heart and the arteries of the lungs.

Who is at risk for truncus arteriosus?

Truncus arteriosus is a congenital heart defect, meaning it develops as a child is growing in the womb. While doctors do not know exactly what causes truncus arteriosus, there are several common risk factors that may increase the chances of a baby being born with a heart condition.

Prenatal diagnosis is important, as babies with truncus arteriosus may have additional organ or chromosomal abnormalities such as DiGeorge syndrome, also known as 22q11.2 Deletion Syndrome. This and other genetic syndromes require specialized treatment from the experts at the Colorado Fetal Care Center and Children's Hospital Colorado.

Get to know our pediatric experts.

Sarah Kelly, PsyD

Sarah Kelly, PsyD

Patient ratings and reviews are not available Why?

John S. Kim, MD

John S. Kim, MD

Patient ratings and reviews are not available Why?