Hypoplastic Aortic Arch

What is hypoplastic aortic arch?

Hypoplastic aortic arch, also called aortic arch hypoplasia (AAH), is a congenital heart defect that affects part of your baby’s aorta. The aorta is a major artery that sends blood out of your baby’s heart to the rest of their body. This artery has a cane-like shape, and healthcare providers call the “handle” of the cane the aortic arch.

Babies with aortic arch hypoplasia have an underdeveloped aortic arch. This means the opening (lumen) of your baby’s aortic arch is narrower than it should be. As a result, it’s harder for blood to flow to the lower part of their aorta (descending aorta) and out to their body.

Who does it affect?

Aortic arch hypoplasia can occur on its own, but it most often occurs in babies who have another congenital heart condition called coarctation of the aorta. This is a narrowing of your baby’s aorta that forms in their descending aorta, near their ductus arteriosus (a fetal blood vessel). When these two conditions happen together, your baby has “coarctation of the aorta with aortic arch hypoplasia.” This is a term you may hear your baby’s healthcare provider use. It means there’s narrowing in an extended portion of your baby’s aorta, not just at one point.

Babies with AAH may also have other heart conditions, including:

• Atrial septal defect (ASD).
• Atrioventricular septal defect.
• Bicuspid aortic valve and aortic valve stenosis.
• Hypoplastic left heart syndrome (HLHS).
• Patent ductus arteriosus (PDA).
• Shone’s syndrome, or multilevel obstruction in the left side of their heart.
• Ventricular septal defect (VSD).

The presence of multiple congenital heart conditions matters because it affects treatment. Your baby may need a specific type of surgery or care plan due to their complex, unique heart anatomy. Some babies with AAH need treatment for several conditions that obstruct normal blood flow through their heart.

What are hypoplastic aortic arch symptoms?

Babies who have coarctation of the aorta with aortic arch hypoplasia usually show symptoms soon after birth. These can include:

• Fast pulse.
• Fatigue.
• Gray or pale skin.
• Heavy sweating.
• Irritability.
• Rapid or labored breathing.
• Trouble with feeding.
• Weak pulse in lower body (at their femoral artery).

What causes aortic arch hypoplasia?

AAH is a congenital heart defect, meaning it’s present at birth. Researchers continue to explore what causes congenital heart defects.

AAH happens when your baby’s aortic arch doesn’t form properly during the early weeks of pregnancy.

How is aortic arch hypoplasia diagnosed?

Healthcare providers use imaging tests to diagnose this condition, typically soon after birth.

Tests that diagnose AAH include:

• Cardiac computed tomography (CT) scan.
• Magnetic resonance angiogram (MRA).
• Transthoracic echocardiogram (TTE).
• Cardiac catheterization.

These tests show the anatomy of your baby’s heart in great detail. They reveal if your baby has other heart defects, and they help your baby’s care team plan the most appropriate treatment.

To diagnose AAH, healthcare providers look at the size of your baby’s aortic arch. Specifically, they look at its diameter, or the width of its opening (lumen). They compare this number with the diameter of other parts of your baby’s aorta, like the ascending or descending aorta. Providers use these numbers to calculate whether the aortic arch diameter is too narrow.

Anatomy of the aortic arch

You may hear your baby’s provider talk about different sections, or segments, of the aortic arch when they diagnose this condition. You might wonder, How can the aortic arch have different segments? Isn’t it already one section of the larger aorta?

Yes, the arch is just one small section of the aorta (it’s the “handle” of the cane). But all the sections of your aorta, including your aortic arch, give rise to many arteries that branch off in different directions. Your aorta is like a main road that has many side streets connected to it. Healthcare providers use the different arteries as landmarks that signal the start or end of a certain segment of your aortic arch. This roadmap is helpful when diagnosing and treating AAH.

Here are some segments of your baby’s aortic arch that you might hear their provider mention:

• Proximal transverse arch: This is the segment between your baby’s brachiocephalic (innominate) artery and left common carotid artery. It’s the part closest to their heart.
• Distal transverse arch: This is the segment between their left common carotid artery and left subclavian artery.
• Aortic isthmus: This is the segment between their left subclavian artery and ductus arteriosus (fetal blood vessel).

Your baby’s provider will identify where your baby’s aortic arch is narrowed, and the extent of the narrowing. This information guides the treatment plan.

What is the treatment for hypoplastic aortic arch?

Babies with a hypoplastic aortic arch need heart surgery to repair the condition. Your baby’s surgeon will explain the specific type of surgery your baby needs. Surgical strategies vary depending on the anatomy of your baby’s heart and other defects that need repair. Your baby may need an incision along the left side of their chest called a thoracotomy, or an incision down the middle of their chest called a sternotomy.

A common surgical technique is resection with extended end-to-end anastomosis. This surgery helps babies who have coarctation of the aorta with aortic arch hypoplasia. A surgeon removes the narrowed portion of your baby’s aorta and joins the lower part (descending aorta) to an elongated incision in their aortic arch.

Surgery improves blood flow in your baby’s aorta. As a result, your aorta can supply enough oxygen-rich blood to nourish your baby’s organs and tissues.

How can I prevent this?

It may not be possible to prevent congenital heart defects like aortic arch hypoplasia. But following your healthcare provider’s guidance on how to have a healthy pregnancy can help lower the risk of AAH or other defects.

In general, you should avoid:

• Alcohol.
• Smoking, vaping and all tobacco products. Also, avoid secondhand smoke.
• Recreational drugs, especially cocaine.

It’s important to visit your provider for your prenatal checkups. Plus, work with your provider before and during pregnancy to manage any health conditions you might have.

What is the outlook for my baby?

Your baby’s healthcare provider is the best person to ask. This is because many factors impact your baby’s outlook, including the presence of other congenital heart defects.

In general, babies treated for aortic arch hypoplasia may have the following issues down the road:

• Recurrent narrowing of their aorta.
• High blood pressure (hypertension).
• Problems feeding or swallowing (due to injury to a specific nerve).

Talk to your baby’s provider about these risks and how to manage them.

How do I take care of my baby after their surgery?

Each baby has unique needs. Talk to your child’s healthcare provider to learn more about managing their short-term and long-term care.

Questions to ask include:

• How should I care for my child at home?
• What medications does my child need?
• Does my child need any therapies to help with physical or neurological function?
• Does my child have any activity restrictions?
• When is it safe for my child to go to daycare? What special instructions should I give the daycare?
• Will my child need other treatments or surgeries?

A note from Cleveland Clinic

Parenting is hard no matter what. But navigating medical care for a child with a heart condition like hypoplastic aortic arch (AAH) brings new challenges every day. You may feel overwhelmed by medical lingo or treatment plans. That’s normal and you’re not alone. Ask your child’s healthcare provider to connect you with resources and support groups. Building a supportive community for yourself and your family can help you manage stress and keep up with the pace of your child’s needs.