Aortic Stenosis

Nemours Cardiac Center at Nemours/Alfred I. duPont Hospital for Children

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Children’s heart conditions can’t be prevented, but a lot can be done to improve and often completely repair their hearts at any age. Thanks to advanced technology and the pediatric heart experts at the Nemours Cardiac Center (based at Nemours/Alfred I. duPont Hospital for Children), most children born with a heart problem — even newborns only hours or days old — can be quickly diagnosed and treated right when it matters the most. At the Cardiac Center, we specialize in early detection and repair of congenital heart defects (also often called, “congenital heart disease”).

If your child’s been diagnosed with aortic stenosis, we’re here to ease your concerns, answer your questions, and give your child the best possible chance for a healthy future.

What Is It?

The aorta is the large blood vessel that delivers oxygen-rich blood from the left ventricle to the aorta. Separating the aorta from the left ventricle is a valve — the aortic valve — which consists of three relatively thin flaps called “leaflets.” When the heart contracts this valve opens, allowing blood to flow out to the body. As the ventricle relaxes and fills with blood, the valve closes, which prevents blood from washing back into the ventricle.

Types of Aortic Stenosis

Aortic stenosis refers to a narrowing of one of the following:
  • aortic valve (this type of aortic stenosis is called “aortic valve stenosis”)
  • the region in the left ventricle (called the “left ventricular outflow tract”)
  • below the valve (this is called “subvalvar aortic stenosis”; the aorta directly above is called “supravalvar” and below is called “subvalvar”)
  • the aorta directly above the valve (this is called “supravalvar aortic stenosis”)

Aortic valve stenosis may be caused by the valve simply being smaller than normal and not growing appropriately, even though the valve itself functions normally. More commonly, the valve itself is abnormal. It may have only two leaflets (a “bicuspid valve”) or occasionally only a single leaflet (a “unicuspid valve”). Most children with a bicuspid valve don’t need surgery. But sometimes the valve leaflets are stuck together or are thicker than normal and the valve can’t open completely, resulting in aortic valve stenosis.

Subvalvar stenosis is a narrowing in the left ventricle below the valve. This may be the result of a problem in the muscle of the left ventricle (called “hypertrophic cardiomyopathy”) or from the build-up of abnormal scar-like tissue (a “subaortic membrane”) on top of the muscle in that area. The cause of subaortic membranes isn’t clear, but they tend to get larger over time and may obstruct or interfere with the function of the aortic valve, resulting in a leak (this is called “aortic insufficiency” or “aortic regurgitation”).

Supravalvar stenosis often occurs with genetic syndromes such as Williams syndrome, but may happen on its own or following earlier cardiac surgeries.

No matter what the cause, aortic stenosis leads to abnormally high pressure in the left ventricle, causing the left ventricular wall to thicken (this is called “hypertrophy”).

How Does the Heart Normally Work?

When your child has a congenital heart defect, there’s usually something wrong with the structure of the heart. In order to understand your child’s condition, it can help to know how the heart should work normally.
Learn More About Normal Cardiac Anatomy »

Nemours’ experts at also offer these helpful resources to help both you and your child understand how the heart works:

How & When Is It Diagnosed?

We may use a variety of tests to measure the severity of the obstruction.

These often include:
  • echocardiogram (“echo”), a completely safe and painless test that uses ultrasound (sound waves) to build a series of pictures of your child’s heart
  • catheterization, performed by inserting a thin plastic, flexible tube (called a “catheter”) into an artery and vein that lead to the heart. Cardiac catheterization is done under sedation with local anesthesia or under general anesthesia, depending on your child’s age and condition.

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How & When Is It Treated?

With aortic stenosis, a thick ventricular wall can eventually result in a stiff heart that can’t relax to allow blood into the ventricle. Children with aortic stenosis should be monitored with imaging studies including echocardiogram (“echo”) and cardiac catheterization. During tests, we’ll look for any leakage of the aortic valve, and perform a repair if the valve leakage increases (which can happen in children with a subaortic membrane).

We usually delay surgery to repair aortic stenosis for as long as possible. But we’ll perform surgery before the high pressure in the left ventricle causes permanent thickening and damage to the muscle.

Types of Surgical Repair for Aortic Stenosis

There are many types of surgical repair for aortic stenosis. The type of surgery a child requires is determined by many factors, including:

  • the location of the obstruction, whether it’s at the valve (valvar), above the valve (supravalvar) or below the valve (subvalvar)
  • the child’s age and size
  • the function of other valves in the heart
  • whether the child has had previous heart surgery
  • other medical conditions

The options for repair of aortic stenosis include:

Balloon valvuloplasty or valvotomy: A valvuloplasty involves inserting a catheter (a tiny, hollow tube) through an artery (usually in the leg) leading to the heart. A balloon at the end of the catheter is then inflated to stretch the valve open and reduce the level of obstruction. Balloon valvotomy is used primarily when the obstruction is located at the level of the valve itself.

Aortic valve repair: Valve repair involves preserving the child’s valve leaflets — repairing them, so they can open and close appropriately. Although this often doesn’t last as long as replacing the valve, the advantage of aortic valve repair is that children’s valves can still grow with them as they get older.

Aortic valve replacement: Valve replacement involves using an artificial valve or a valve from a donor to replace the child’s non-functioning valve. There are multiple options for different types of valve replacement — which your Nemours Cardiac Center surgeon can explain — including:

  • mechanical valves made of carbon
  • valves made of animal tissue (called “bioprosthetic” or “tissue” valves)
  • donated human valves (called “homografts”)

None of these valves grow with a child. So that means children either must be big enough for the valve to last into adulthood, or they’ll need additional procedures to replace the valve with a bigger version.

Ross procedure: The Ross procedure is done in order to replace an aortic valve with a new valve that can grow with a child. Instead of taking an artificial valve, the pulmonary valve (which sits between the right ventricle of the heart and the pulmonary artery — the large blood vessel that delivers oxygen-poor blood to the lungs) is taken out and used to replace the non-functioning aortic valve. An artificial valve is then used to replace the pulmonary valve. This is done because growth and function of the pulmonary valve is less important than growth and function of the aortic valve. Children can grow into adulthood with a pulmonary valve that doesn’t work (or doesn’t work well). Although this is a larger operation, it allows the new aortic valve to grow as the child grows into adulthood.

Subaortic membrane resection: In patients with a subaortic membrane (scar-like tissue causing an obstruction below the valve “subvalvar”), it’s usually necessary to remove the membrane from the muscle of the heart and the aortic valve leaflets. Occasionally, we may also perform a resection of muscle (called a “myectomy” or “myotomy”) to enlarge the opening below the valve.

Left ventricular myectomy: When the obstruction of the flow from the heart into the aorta is caused by abnormal thickness of the muscle, we may perform a resection of the thick muscle to enlarge the opening and allow blood to move freely from the heart to the aorta.

Repair of supravalvar stenosis and patch aortoplasty: When the obstruction to blood flow is located in the aorta above the valve, we may use a variety of techniques to make that area wider. Our cardiac surgeons will often try to use a child’s own tissue in order to preserve as much potential for growth as possible. But, at times, we’ll use a patch to increase the size of the blood vessel. The patch may be one of the following:

  • from the child’s own tissue (usually the sac around the heart, called the “pericardium”)
  • tissue from the sac around the heart of a cow (called the “bovine pericardium”)
  • human tissue (called a “homograft”)
  • artificial tissue such as polytetrafluoroethylene (“PTFE” or Gore-Tex)
  • woven tissue (Dacron)

All of these options are safe and work well for the children we treat. Your child’s Nemours Cardiac Center heart surgeon will usually determine, in the operating room, which kind of patch will work best for your child.

Learn More About Heart Surgery »

How Will It Affect My Child Long Term?

The biggest challenge for children with aortic stenosis is that the problem can reoccur as they grow. This may happen for a variety of reasons, including scar tissue or a valve (such as a mechanical valve) that doesn’t grow as the child gets bigger. So children may need multiple operations.

To monitor how the repaired or replaced aortic valve is working and to determine whether children need any additional procedures as they grow, we usually use:

  • echocardiogram (“echo”), a completely safe and painless test that uses ultrasound (sound waves) to build a series of pictures of your child’s heart
  • catheterization, performed by inserting a thin plastic, flexible tube (called a “catheter”) into an artery and vein that lead to the heart. Cardiac catheterization is done under sedation with local anesthesia or under general anesthesia, depending on your child’s age and condition.

If your child has aortic stenosis, know that at the Nemours Cardiac Center we’re here to give your child the very best, most comprehensive and compassionate care. Our goal is to guide your family, from start to finish, through your child’s heart defect journey — and to help your child live the healthiest, most fulfilling life possible.

Learn More About Congenital Heart Defects »

Why Choose Us

From our outcomes to our family-centered care, find out all of the reasons why your child’s heart will be in good hands at the Nemours Cardiac Center. Learn More »

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Information for Patients

Outpatient Services and Inpatient Units: (302) 651-6660

After 5 p.m. and Weekends:

Cardiac Intensive Care Unit: (302) 651-6644
General Inpatient Unit, 2B: (302) 651-6690


+1 (302) 651-4993

Michael's Aortic Stenosis Story

Meet Michael, who was 6 weeks old when he was diagnosed with aortic stenosis and treated by the pediatric heart experts at the Nemours Cardiac Center.