Interrupted Aortic Arch

What is Interrupted Aortic Arch (IAA)?

An interrupted aortic arch (IAA) is a complete interruption, or gap, in the aorta that prevents normal blood flow through the heart. There are three types of IAA, based on where the gap in the aorta occurs.

Interrupted Aortic Arch Types

Type A: This is a complete interruption in the aorta that occurs after the left subclavian artery branch. 30-40% of babies with IAA have Type A. 

Type B: This is a complete interruption in the aorta that occurs between the left common carotid artery and the left subclavian artery branch. Type B can be related to possible genetic conditions. 50-60% of babies with IAA have Type B. 

Type C: This is a complete interruption in the aorta between the innominate artery and the left common carotid artery.  Only about 4% of babies with IAA have Type C.

See illustrations that show an example of a heart with IAA

Causes of IAA

IAA happens very early in a baby’s development, usually between the 5th and 7th week of fetal development. Doctors do not know exactly what causes this defect, but it is usually associated with other heart conditions as well as some genetic disorders such as DiGeorge syndrome (22q11.2 deletion syndrome). 

IAA is a relatively rare defect—only 1% of all congenital heart defects are IAA. However, it is almost always associated with other cardiac defects, such as ventricular septal defect, patent ductus arteriosus, bicuspid aortic valve, subaortic stenosis, aortopulmonary window, truncus arteriosus, d-transposition of the great arteries, double outlet right ventricle, atrioventricular septal defect, or single ventricle.

Symptoms of IAA

Babies with IAA have poor circulation and weak or absent pulse on the lower half of their body and in some cases, the left arm. 

Within the first three days after delivery, the ductus arteriosis—a blood vessel that allows for circulation during fetal development—will typically close. In babies with IAA, when this vessel closes, the blood flow to the body is stopped. Early diagnosis and intervention for IAA is critical for the baby’s survival.

How is IAA treated?

The only treatment for IAA is surgical repair of the aorta to allow for healthy blood flow. Babies with IAA will be admitted to the ICU immediately after birth. Then, the care team will decide on timing for surgery.

Receive expert care at Children’s Mercy

Our Heart Center team includes many pediatric cardiology specialists who will work together to care for your child. Your child’s care team may include: 

• Pediatric cardiologists
• Surgeons 
• Nurse practitioners 
• Respiratory therapists 
• Nurses 
• Sonographers
• Child Life specialists 
• Social workers 
• Psychologists 
• Chaplains 
• Music therapists
• Additional Fetal Health Center staff 

Children with congenital heart conditions like IAA will need continued care from a cardiologist throughout their lifetime. 

Read more about the Heart Center and Fetal Health Center at Children’s Mercy.