Fontan Procedure

The Fontan procedure is a life-changing heart surgery that helps children born with only one working heart chamber survive and grow. This operation, usually performed when children are between 18 months and 5 years old, creates a new pathway for blood to flow through the body, allowing children with complex heart defects to live into adulthood.

Table of contents

• What Is the Fontan Procedure?
• Why Is the Fontan Procedure Done?
• How the Fontan Procedure Works
• Types of Fontan Procedures
• The Staged Surgical Approach
• What Happens During Surgery
• Recovery and Hospital Stay
• Life After Fontan Surgery
• Long-Term Follow-Up Care
• Possible Long-Term Complications

What Is the Fontan Procedure?

The Fontan procedure is a type of open-heart surgery designed to help children who were born with only one working lower heart chamber, called a ventricle (a pumping chamber of the heart).^[1] This surgery improves blood flow in people who have a single ventricle (one working heart chamber instead of two), which happens because of several birth defects of the heart.^[2]

The procedure was first introduced in 1968 by doctors Francis Fontan and Eugene Baudet from France to treat patients with a condition called tricuspid atresia (when the valve between the upper and lower right heart chambers doesn’t form).^[7] Since then, the surgery has evolved and helped many thousands of children with different types of heart problems survive into adulthood.^[3]

Children who need this surgery usually have it when they’re 18 to 36 months old, though it can be performed in children between ages 2 and 15, most commonly between 3 and 5 years old.^[1][2] Each year, healthcare providers in the United States perform about 1,000 Fontan procedures, and an estimated 50,000 to 80,000 people worldwide have had this operation.^[2]

Why Is the Fontan Procedure Done?

The Fontan procedure is done for children who are born with heart problems where one of the heart’s ventricles or one of the main valves doesn’t form properly before birth.^[2] These conditions are often called single ventricle defects (heart problems where only one pumping chamber works properly). Single ventricle defects occur in about 5 out of every 100,000 births.^[4]

The Fontan procedure can treat several heart conditions, including:^[2][4]

• Hypoplastic left heart syndrome (the most common reason for a Fontan procedure, where the left side of the heart is too small)
• Tricuspid atresia (when the valve between the upper and lower right chambers doesn’t form)
• Double outlet right ventricle (when both major blood vessels come from the right ventricle)
• Hypoplastic right heart syndrome (when the right side of the heart is too small)
• Pulmonary atresia with intact ventricular septum (when the valve leading to the lungs doesn’t form)
• Unbalanced atrioventricular canal defects
• Severe Ebstein’s anomaly
• Double inlet left ventricle
• Heterotaxy syndrome (when some organs aren’t in their normal locations)

• Heart
• Heart ventricles
• Pulmonary artery
• Inferior vena cava
• Superior vena cava
• Right atrium
• Lungs

How the Fontan Procedure Works

In a normal heart, there are four chambers: two upper chambers called atria (receiving chambers) and two lower chambers called ventricles. Normally, the right ventricle pumps blood to the lungs to get oxygen, and the left ventricle pumps the blood with oxygen to the body.^[1]

When one ventricle is too small or doesn’t work, the other ventricle has to do all the work. It has to pump both oxygen-poor blood to the lungs and oxygen-rich blood to the body. The blood that it pumps to the body is a mix of oxygen-rich blood and oxygen-poor blood. The body can’t grow and thrive properly if it doesn’t get enough oxygen.^[1]

The Fontan procedure lets oxygen-poor blood from the lower part of the body go straight to the pulmonary artery (the blood vessel leading to the lungs) for oxygen instead of going through the heart first.^[2] This blood flows in a passive way, without a pumping ventricle to move it. After the blood picks up oxygen in the lungs, it returns to the heart, and the single working ventricle only has to pump oxygen-rich blood to the body.^[2]

This way, the single ventricle only pumps blood to the body and only pumps blood with high oxygen to the body. There is no more mixing of oxygen-rich blood and oxygen-poor blood.^[1]

Types of Fontan Procedures

There are different variations of the Fontan procedure. The two main types used today are:^[4][7]

Extracardiac conduit: In this approach, a Gore-Tex tube is placed outside the heart to direct blood flow from the lower part of the body to the lungs. This type of procedure doesn’t involve working directly inside the heart, so there is a lower chance of problems. It is often chosen because it’s simpler and has a lower risk of causing arrhythmias (abnormal heart rhythms).^[4]

Lateral tunnel: In this approach, doctors create a tunnel inside the heart to reroute blood from the lower body to the lungs. While it involves working inside the heart, this method lets the tunnel grow with the child, making it a better choice for some children. However, it may have a slightly higher risk of arrhythmias than the extracardiac conduit.^[4]

Doctors will choose the best approach based on the child’s specific heart anatomy, the surgeon’s experience, and the individual needs of each patient.^[4]

The Staged Surgical Approach

The Fontan procedure is usually the third and final surgery in a series of operations for children with single ventricle heart defects.^[2][5] This staged approach is designed to gradually redirect blood flow and allow the child’s body to adapt.

Before having the Fontan procedure, children usually need to have at least one or two other procedures first:^[2][5]

Stage 1: Norwood procedure or similar operation (performed within several days of birth): This first operation ensures that blood flow is controlled enough to prevent damage to the heart and lungs, and that enough blood reaches the lungs to keep the child alive until the second operation.^[5]

Stage 2: Glenn procedure or hemi-Fontan (usually occurs within six months of birth): During this surgery, the superior vena cava (the large vein that carries oxygen-poor blood from the upper body to the heart) is disconnected from the heart and attached to the pulmonary artery. After this operation, oxygen-poor blood from the upper body goes to the lungs without passing through the heart.^[2][5]

Stage 3: Fontan procedure (usually performed between ages 2 and 5): This final surgery completes the process by directing blood from the lower body to the lungs as well.^[6]

Other procedures that may be done before the Fontan include the Blalock-Taussig-Thomas (BTT) shunt or pulmonary artery band.^[2]

What Happens During Surgery

During the Fontan procedure, the surgeon performs the following steps:^[1]

The surgeon disconnects the inferior vena cava (IVC) (the large vein that carries blood from the lower body) from the heart and connects it to the pulmonary artery using a tube called a conduit. The surgeon may also make a small hole between the conduit and the right atrium. This hole, called a fenestration, lets some blood still flow back to the heart. It prevents too much blood from flowing to the lungs right away, giving them time to adjust.^[1]

Doctors can close the fenestration later by doing a cardiac catheterization procedure (a procedure where a thin tube is inserted into blood vessels to reach the heart).^[1]

Not every child is a good candidate for the Fontan procedure. The child’s healthcare provider will check to make sure they’re suitable for the surgery. For example, their working ventricle needs to be strong enough to pump well, and the lungs have to be healthy enough to receive blood flow without a pumping action.^[2]

Recovery and Hospital Stay

Children who have the Fontan procedure usually spend 1 to 2 weeks in the hospital to recover.^[1] They get round-the-clock care and monitoring. They also receive medicines to help the heart and improve blood flow, and they will keep taking some of these medicines at home.^[1]

During the hospital stay, the care team teaches parents how to care for their child at home. Children usually can go home when they are feeding well, growing well, and gaining weight.^[1]

Life After Fontan Surgery

The Fontan surgery makes it possible for babies with complex heart defects to survive childhood and into adulthood. However, this surgery is not a cure.^[13] Most people live another 30 years or more after surgery.^[2]

Many children thrive and do well after heart surgery. People with Fontan surgery can be very active with few limitations, though they should participate in regular exercise as guided by their doctor.^[13] Regular exercise is very important for keeping healthy. Both the heart muscle and the breathing muscles help the blood flow properly in people with Fontan surgery, and stronger muscles make for better blood flow to the body overall.^[13]

For people with Fontan surgery, it is important to find an exercise activity that they can do regularly, though sometimes they may need to exercise at their own pace. The type of exercise activity should be discussed with their heart doctor.^[13] Studies have shown that high rates of physical activity are associated with improved quality of life in adults with Fontan circulation.^[19]

At home, parents should follow the care team’s instructions about giving medicines, attending follow-up doctor visits, and watching for signs like blueness of the lips or nails.^[1]

Long-Term Follow-Up Care

People who have had the Fontan procedure need lifelong specialized follow-up care.^[13] They’ll need to see a cardiologist (heart doctor) regularly and get tests such as:^[1]

• EKGs (tests that record the electrical activity of the heart)
• Echocardiograms (ultrasound pictures of the heart)
• Lab tests
• Occasional cardiac catheterizations

Cardiac catheterization is a procedure that lets cardiologists check how the heart is working and perform some types of treatments.^[1]

Excellent dental hygiene is very important for keeping the heart healthy. Normal bacteria in the mouth can be very harmful if they get into the heart. The best way to protect the heart is by keeping the mouth and teeth healthy through regular brushing, flossing, and visiting the dentist at least once a year. Some patients are advised to take antibiotics before dental procedures.^[13]

Women with Fontan surgery can become pregnant, but pregnancy is considered higher risk and requires specialized care. These women need to be followed by specialized heart and obstetric doctors throughout their pregnancy. Discussing family planning and birth control methods is an important part of healthcare for people with Fontan surgery. Some birth control methods are not safe for women with Fontan surgery. In general, progesterone-only birth control methods are preferred to reduce the risk of blood clots.^[13]

Possible Long-Term Complications

Long-term complications after Fontan surgery are common, and ongoing specialized follow-up is needed to keep people as healthy as possible for as long as possible.^[13] The procedure is associated with several potential complications due to the unique way blood flows through the body.^[3]

Common long-term complications include:^[10][13]

• Heart rhythm problems (arrhythmias), which may feel like skipped beats or a racing heart
• Blood clots
• Heart failure (when the heart muscle becomes weak)
• Low blood oxygen levels
• Kidney problems
• Liver congestion or cirrhosis (scarring of the liver)
• Increased pressure in the veins that bring blood back to the heart
• Protein-losing enteropathy (a condition where protein leaks from the digestive system)
• Plastic bronchitis (formation of rubbery material in the airways)

If a patient with Fontan surgery experiences new symptoms such as decreased ability to exercise, fatigue, shortness of breath, or changes in heart rhythm, they should contact their heart doctor right away.^[13]

Despite these challenges, specialized care centers provide comprehensive, multispecialty management to monitor and treat any issues that affect the heart, lungs, liver, and kidneys. These specialized clinics offer regular screenings and continuous monitoring to help identify potential issues before they become severe complications.^[8]