Interrupted Aortic Arch (IAA)

What Is Interrupted Aortic Arch (IAA)?

Interrupted aortic arch (IAA) is a rare heart condition that occurs when a section of the curved part (arch) of the aorta is missing. The middle section of the aortic arch (transverse aortic arch) supplies blood to a child’s head and arms. In IAA, an upstream section of the aortic arch doesn’t connect to the downstream section. The downstream section continues normally as the descending aorta, carrying blood to the lower body.

This gap or interruption means oxygen-rich blood can’t flow from your baby’s heart to their lower body in the usual way. Instead, blood must flow through a small blood vessel called the ductus arteriosus into the descending aorta. 

Most babies have a ductus arteriosus while in the womb. This blood vessel normally closes on its own a few days after birth. While it is open, it may still deliver enough blood to a baby’s body for a few days. But once the blood vessel closes, and blood can’t flow to the lower part of the body, a baby will become critically ill. 

To prevent this from happening, healthcare providers give an IV medication called prostaglandin E1 (PGE1). It keeps the ductus arteriosus open to preserve blood flow to the body. This is a temporary treatment until heart surgery takes place to close the gap.

What Is the Aorta?

The aorta is the largest blood vessel in the body. It carries blood from the heart to the rest of the body. The aortic arch is the curved, u-shaped segment at the top of the heart that connects the ascending and descending parts of the aorta. 

What Are the Complications of IAA?

IAA is a critical, life-threatening condition that requires surgery soon after birth. Some babies also have other congenital heart defects that require treatment, usually during the same surgery. These conditions include:

• Blockage to blood flow from the heart’s left lower chamber (ventricle)
• Ventricular septal defect or VSD (opening or hole between the heart’s lower chambers)

What Are the Types of IAA?

The location of the missing arch segment determines the type of IAA. Types include:

• Type A: The gap is between the ductus arteriosus and the left subclavian artery, which carries blood to your baby’s left arm, head and neck. 
• Type B: This most common type occurs when there’s a gap between the left subclavian artery and the left common carotid artery, which carries blood to the left side of the head, neck and brain. IAA type B is strongly associated with 22q11.2 deletion syndrome (also called DiGeorge syndrome). This genetic condition can affect multiple body systems, including the heart. 
• Type C: This least common type occurs when there’s a gap between the left common carotid artery and the brachiocephalic (innominate) artery, which carries blood to the upper right side of your child’s body.

What Causes IAA?

Experts don’t know the exact cause of IAA. The condition occurs early in pregnancy while a baby’s cardiovascular system is still forming. It affects approximately 1 percent of all babies born with congenital heart disease. IAA is most common in children who have DiGeorge syndrome. 

What Are the Signs and Symptoms of IAA? 

IAA is often diagnosed while a baby is still in the womb. Newborns receive medication to prevent symptoms.

When IAA is undiagnosed, symptoms typically appear within a baby’s first two weeks as the ductus arteriosus starts to close. Your baby may have:

• Difficulty breathing or rapid breathing
• Extreme fatigue
• Fast heart rate
• Feeding issues and failure to thrive
• Fewer wet diapers (low urine output)
• Profuse sweating
• Skin that’s paler or cooler than normal

How Is IAA Diagnosed?

A prenatal ultrasound often detects IAA. If your unborn baby has a potential heart problem, your OB-GYN will refer you to a maternal-fetal medicine (MFM) doctor and a fetal cardiologist. MFM doctors (perinatologists) specialize in high-risk pregnancies. Fetal cardiologists manage congenital heart problems before babies are born. 

To make your care more efficient at Lurie Children’s, you will see both subspecialists in one single location and appointment visit at The Chicago Institute for Fetal Health. Here, you will undergo a fetal echocardiogram (echo) to view your unborn baby’s heart. You may also receive other fetal imaging tests to help your doctors develop the most comprehensive treatment plan for you.

Diagnosing IAA in Newborns

If doctors know your baby will be born with IAA, they order different cardiac imaging tests. These tests determine the type of IAA and help guide treatment decisions. These tests may include: 

• Transthoracic echocardiogram (TTE) 
• CT scan
• Electrocardiogram (ECG/EKG) 
• MRI

In rare cases, a baby may receive an IAA diagnosis after childbirth. All newborns undergo a critical congenital heart disease (CCHD) screen before leaving the hospital. This screening test measures oxygen levels in the blood. It sometimes detects IAA and other previously undiscovered heart issues. Occasionally, doctors diagnose a baby with IAA after they develop symptoms from decreased blood flow to the body. They may also detect a heart murmur.

How Is IAA Treated?

Newborns with IAA require heart surgery to reconnect the two separated parts of their aorta. At Lurie Children’s, a team of doctors cares for babies with IAA, including specialists in:

• Fetal and pediatric cardiology
• Neonatal and cardiac intensive care 
• Neonatal cardiac surgery 

The entire team will review your baby’s tests from before and after they’re born. They guide your family on the best timing and precise details of surgery, which usually takes place in the first couple of weeks. 

Newborns with IAA stay in the Regenstein Cardiac Care Unit (CCU) at Lurie Children’s before and after surgery and through discharge. The CCU is a highly specialized hospital unit uniquely designed to meet the needs of babies with congenital heart disease from birth until they go home. 

Presurgical Care

Soon after birth, your baby will start on an IV of PGE1 to keep the ductus arteriosus open. An open or patent ductus arteriosus (PDA) helps oxygenated blood reach the lower body. During this time, your baby may receive oxygen through a ventilator or nasal cannula (flexible tube) to help minimize stress on their body and take pressure off their heart and lungs. They may also receive IV nutrition.

In the days before surgery, your baby will receive additional imaging tests to make sure other organs, such as their brain and kidneys, are working as they should. Your baby’s care team will review these test results and work together to develop a comprehensive treatment plan.

Neonatal Heart Surgery

Neonatal heart surgeons at Lurie Children’s have deep expertise in correcting IAA. The exact surgical details depend on the type of IAA and whether there are any additional heart defects. Your child’s care team will make sure you understand the surgical treatment plan. 

Generally, surgery for IAA involves:

• Connecting and closing the gap between the upstream and downstream portions of the aorta to form a continuous, uninterrupted aortic arch
• Closing the hole between the left and right ventricles to correct VSD (if needed)
• Correcting other heart defects (if needed)

After Heart Surgery

After surgery, your baby recovers in our CCU. Each baby’s recovery is unique. Most babies stay in the hospital for at least two weeks to give them time to get stronger, adjust to the new blood circulation and wean off breathing support. Once your baby’s cardiovascular system is stable, the focus shifts toward getting your newborn home. 

Your child’s care team will ensure your baby:

• Breathes without additional support
• Grows and gains weight 
• Is on a stable regimen of medications, if needed

At Lurie Children’s Hospital, an ear, nose and throat (ENT) doctor (also called an otolaryngologist) performs a scope procedure to view your baby’s vocal cords. Surgery and breathing support may affect a child’s ability to feed, swallow and make sounds (talk). If your baby has vocal cord issues, we’ll work with you to ensure safe feedings. In some cases, a baby may go home with a nasogastric tube to receive nutrients until their vocal cords heal.

As you prepare to take your baby home, we’ll partner with you to ensure your family has adequate support and medical supplies. We also schedule follow-up appointments. Before discharge, your baby will also receive additional testing required for all newborns, regardless of whether they have a congenital heart defect. 

What Is Lurie Children’s Approach to Caring for Children With IAA?

Lurie Children’s is among a select few healthcare systems in the region with a dedicated Complex Congenital Heart Disease (CCHD) Care Center. Your family benefits from:

• Continuum of care: We manage CCHDs from before birth throughout childhood. When the time comes, older children transition to Lurie Children’s Adult Congenital Heart Disease (ACHD) Program.
• Heart surgery expertise: Heart surgery takes place at our Level I Children’s Surgery Center. This highest-level distinction from the American College of Surgeons (ACS) reflects our commitment to patient safety, exceptional outcomes and quality care.
• Dedicated heart team: The cardiologist providing care during your baby’s hospital stay will serve as your family’s primary contact. A different pediatric cardiologist will oversee your child’s care after they go home. 
• Support for your family: While your baby is in the CCU, a case manager will help to schedule and coordinate appointments after discharge. Your family also has access to spiritual care services (chaplains), social workers and palliative care specialists. 
• Neurodevelopmental services: Our NICU-Cardiac Neurodevelopmental Program (NCNP): Child & Adolescent Clinic is among a select few programs of its kind nationally. We help children with congenital heart defects — who have a higher chance of neurodevelopmental issues — reach their potential.
• Genetic counseling for families: Families affected by DiGeorge syndrome and IAA benefit from genetic testing and counseling at our Cardiovascular Genetics Center (CVGC).
• Help with feeding and speech issues: Our speech therapists manage feeding, speech and swallowing problems. We also have registered dietitians who help ensure that children with IAA are growing well. They can also help with weaning off of tube feeding.

The Heart Center at Lurie Children’s 

The nationally recognized Heart Center at Lurie Children’s is one of a select few in the country with a dedicated program for children with complex congenital heart defects. Newsweek and U.S. News & World Report rate our pediatric cardiology and cardiac surgery programs among some of the best in the country. Your family receives compassionate care starting in pregnancy that goes throughout your child’s youth and into their adulthood.

Learn more about our Heart Center