What to Know About the Fontan Procedure

Medically Reviewed by Dany Paul Baby, MD on April 27, 2022

Children are sometimes born with heart problems (congenital heart diseases). Heart surgeons can correct many of them to restore a normally working heart. 

Some children, for instance, are born with only one working ventricle. While it sometimes isn't possible to create two working ventricles surgically, the Fontan procedure is a palliative surgery that reduces the mixing of de-oxygenated and oxygenated blood. It reduces the work of the heart and provides a better oxygen supply to the body. 

The Fontan procedure is an open heart surgery requiring several days of hospital stay and lifelong follow-up and medication.

Congenital Heart Problems in Children

Many children are born with congenital heart disease (CHD). Some of these conditions, like small atrial and ventricular septal defects, cause only minor problems and resolve on their own.

A few children, though, are born with major defects. These often make survival difficult or impossible without surgery. In some congenital heart diseases, the child has only one working ventricle instead of two. Some of these are:

  • Hypoplastic left heart syndrome
  • Tricuspid atresia
  • Double outlet right ventricle

Usually, the blood from all over the body returns to the heart's right side through the two vena cavas. Blood with a low oxygen content is pumped to the lungs by the right ventricle. Oxygenated blood returns to the left side of the heart through the pulmonary veins. The left ventricle pumps it to all the parts of the body. 

When there is only one working ventricle, the blood from the lungs and the body are mixed together and pumped out. Consequently, tissues and organs all over the body get blood with low levels of oxygen. 

Ideally, surgeons operate to create a biventricular heart — a heart with two functioning ventricles. This would return the circulation's physiology to normal. This isn't possible for all children with CHD, though. Sometimes, the heart is so malformed that a biventricular heart cannot be surgically created.

In such cases, surgeons perform a Fontan procedure. It provides partial relief to the child's heart and body.

What Is a Fontan Procedure?

The Fontan procedure is a form of open heart surgery. If your child needs it, it will probably be performed between ages 18 and 36 months. 

The inferior vena cava brings blood from the lower half of the body. As part of the Fontan procedure, it is disconnected from the heart and joined to the pulmonary artery. 

A tube, or conduit, may be needed. This directs low-oxygen blood away from the heart and to the lungs. This blood gets oxygenated in the lungs and returns to the heart. The heart then pumps oxygen-rich blood to all the organs and tissues. 

The Fontan procedure is the third of three surgical procedures for children with hypoplastic left heart syndrome and other severe anomalies. The first step is a Norwood procedure. It is followed by the Glenn procedure.

The Fontan procedure doesn't restore the heart to normal. It is considered palliative surgery, but long-term outcomes are improving. 

Girls who had the procedure in childhood, for instance, have gone on to have pregnancies and successfully deliver children.

After the Fontan Procedure

The Fontan procedure is a major surgery lasting several hours. It alters the structure of the heart and the great blood vessels. Bloodflow in the heart and lungs is redirected. 

Your physician will keep your child in the hospital for several days. During this time, they will monitor your child's heart and circulation and how it is adapting to the changes brought about by the Fontan procedure. 

Your physician will discharge you when your child is eating and growing well. They will want you to bring your child back, though, for regular checks and testing. Some children may have problems affecting the heart, lungs, and other systems in later life. Blood clots frequently occur. Your child may require lifelong medication to prevent clotting.

Your physician will monitor your child for any complications. Children who receive a Fontan procedure are at risk for many complications because of their abnormal circulation, including:

  • Heart failure
  • Atrioventricular valve regurgitation (backflow through the heart's valves}
  • Arrhythmia (disturbance of the heart's rhythm)
  • Protein-losing enteropathy (a digestive system disorder)
  • Plastic bronchitis (a disorder affecting the air passages in the lungs).

Some children need further surgery to correct problems and complications. Some children may even require a heart transplant.

Norwood Procedure

Children with CHDs that have only a single working ventricle are very sick at birth. The Norwood procedure is performed soon after birth to give these babies a chance at survival. It is the first of the three-step surgery for such CHDs. It involves connecting the aorta and pulmonary arteries and enlarging the underdeveloped aorta. The two upper chambers of the heart are joined by removing the muscular wall between them.

The Norwood procedure is a very risky surgery, and some babies do not survive it. It is done on babies with CHDs that would not let them live for long. This surgery makes sure that blood reaches the lungs. The right ventricle pumps blood to both the lungs and the body after this procedure.

Glenn Procedure

The Glenn procedure is the second operation in the three-step surgery for the hypoplastic left heart syndrome. It is usually done at about 6 months of age. It is an open heart surgery and takes several hours.

The superior vena cava is disconnected from the heart and joined to the pulmonary artery. This diverts the low-oxygen blood returning from the upper half of the body to the lungs.

The Glenn procedure reduces the low-oxygen blood entering the heart. The organs and tissues all over your baby's body start getting blood with higher oxygen content. This procedure also reduces the strain on the heart.

Fontan Procedure Outcomes

With modern anesthesia and heart-lung machine support, more than 90% of children recover from this surgery. Hospitals that perform a large number of such procedures have mortality figures as low as 3%. Though it is not a complete repair of the defect, the Fontan procedure produces twenty-year survival rates in 84% of cases. 

The Fontan procedure does not restore the normal structure of the heart. The systemic circulation, which supplies the entire body, is dependent on the right ventricle. This ventricle is not normally as strong as the left ventricle. 

Heart failure occurs in some children who have had the Fontan procedure. Other problems may include arrhythmias (disorders of the rhythm of the heart) and increasing resistance in the lung blood vessels. 

Babies born with severe CHDs like the hypoplastic left heart syndrome previously had poor life expectancy. Most of them would not see their first birthday. The development of the Norwood, Glenn, and Fontan procedures, though, has improved outcomes for many such children.

Show Sources

Children's Wisconsin Hospital: "Fontan procedure," "Glenn procedure," "Norwood procedure."
Circulation: "Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association," "The Fontan Procedure."
John Hopkins Medicine: "Hypoplastic Left Heart Syndrome Surgery: The Glenn Procedure."
Nemours Children's Health: "The Fontan Procedure."

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