Why Does a Baby Need the Fontan Procedure? Without medicines and a series of three surgeries to rebuild the heart, babies with hypoplastic left heart syndrome (HLHS) won't survive. The left side of the heart can't be fixed, so the goal of the surgeries is to rebuild parts of the heart and "redirect" the way blood flows. The last surgery in the series is the Fontan procedure. Children get this after the Glenn procedure, usually when they're 18 to 36 months (3 years) old. Until now, blood low in oxygen from the lower part of the body has mixed with blood high in oxygen. What Is the Fontan Procedure? The Fontan procedure is a type of open-heart surgery. The goal is to: Make blood from the lower part of the body go directly to the lungs. This lets the blood pick up oxygen without having to pass through the heart. In babies with hypoplastic left heart syndrome, low-oxygen blood from the lower part of the body mixes with high-oxygen blood. After the Fontan procedure, low-oxygen blood and high-oxygen blood no longer mix. This lets the heart deliver only high-oxygen blood to the body. What Happens During the Fontan Procedure? The Fontan procedure involves redirecting blood flow from the lower body to the lungs. In the Fontan procedure: The inferior vena cava (IVC) is disconnected from the heart and routed directly to the pulmonary artery. Usually a large tube called a "conduit" is added to make the connection. Often, a small hole or "fenestration" is created between the Fontan conduit and the right atrium. This lets some blood still flow directly back to the heart and acts as a "pop-off" valve as the lungs get used to the extra flow from the lower part of the body. This hole can be closed later with a cardiac catheterization procedure. Blood from the lower body now goes to the pulmonary artery, and then to the lungs, without having to go to the heart. The right ventricle remains the main pump and now just sends blood coming back from the lungs with oxygen out to the body. After the Fontan procedure, blood high in oxygen and blood low in oxygen are separated. That means more oxygen can get to the body. What Happens After the Fontan Procedure? Children who have the Fontan procedure usually spend 1 to 2 weeks in the hospital to recover. They get-around-the-clock care and monitoring. They also get medicines to help the heart and improve blood flow. What Else Should I Know? Many children thrive and do well after heart surgery. They'll need to get lab tests often and occasional catheterizations. To help keep your child as healthy as possible: Go to all doctors visits. Give all medicines as directed. Follow the guidelines from your care team. Sometimes, the three heart surgeries may not totally fix all heart problems or the right ventricle can tire out over time. In these cases, a child may need a heart transplant. Back to Articles Related Articles Hypoplastic Left Heart Syndrome (HLHS) Hypoplastic left heart syndrome (HLHS) is a birth defect of a baby’s heart. The left side of the heart doesn’t grow as it should, making it smaller and weaker than normal. Read More Hypoplastic Left Heart Syndrome Surgery: The Norwood Procedure The Norwood procedure is open-heart surgery done as the first of three surgeries to treat hypoplastic left heart syndrome (HLHS). Read More Hypoplastic Left Heart Syndrome Surgery: The Glenn Procedure The Glenn procedure is open-heart surgery done as the second of three surgeries to treat hypoplastic left heart syndrome (HLHS). Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.