Single ventricle physiology is typically treated through a series of two or three palliative (non-curative) surgeries in the first few years of life. Children with these heart defects require lifelong cardiac care to ensure they have every opportunity to lead healthy lives as they grow. Unfortunately, many children will require additional operations or cardiac catheter-based procedures, complex testing, multiple hospitalizations, and frequent outpatient follow-up. Our single ventricle team is uniquely equipped to help these patients and their families face these challenges both inside and outside the hospital.
The First Operation: Aorto-pulmonary Shunts, Pulmonary Artery Banding or Stage 1 Norwood Procedure
In the first several months of life, it’s important for the body to have a balanced circulation such that the amount of blood flow to the lungs matches the blood flow to the rest of the body. The amount of blood flow to the lungs determines the baby’s oxygen levels and the blood flow to the rest of the body provides nutrients and oxygen to all the vital organs. Some babies are born with their circulation already balanced. Others will need an operation in the first several weeks of life to help get to a better balance.
Some babies with single ventricle physiology may require additional blood flow to the lungs. A surgical shunt procedure may be performed to direct some extra blood from the body to the lungs.
Other babies may have too much circulation to the lungs and require a pulmonary artery banding procedure to restrict the blood flow to the lungs.
Patients with hypoplastic left heart syndrome and other defects with a small left heart and aorta require additional surgery to enlarge the aorta, which is done through a surgical operation called the Stage 1 Norwood procedure. The Norwood procedure is performed as soon as the baby is physically ready after birth. The heart typically works very hard after this surgery, and these babies require careful monitoring and feeding support.
The Second Operation: The Bidirectional Glenn Procedure
In the typical heart, the superior and inferior vena cavae normally carry the blue (deoxygenated blood) from the upper and lower parts of the body back to the heart. In this second operation, the Glenn procedure, the superior vena cava is connected directly to the pulmonary arteries so that blue blood from the upper body drains directly into the lungs, bypassing the heart. If a prior surgical shunt was performed, this shunt is taken down.
The Glenn procedure is usually performed around four to six months of age, depending on the health of the child and the specific heart defect. This surgery relieves part of the single ventricle’s volume and workload, but the child will still be considered “blue.”
There are also some children who required a shunt or a pulmonary artery band shortly after birth may still be able to have their heart separated into the more typical four chambers. This is called a “biventricular repair”. While these children often also require future procedures and surgeries, they will not need the Fontan procedure and are no longer considered to have single ventricle heart disease.
The Third Operation: Fontan Procedure
The third step in the stages of single ventricle surgeries connects the inferior vena cava, the blood vessel that carries deoxygenated blood from the lower body, to the pulmonary arteries. In our center, this is typically performed using an extracardiac Gore-Tex® tube graft and is called the extracardiac Fontan operation. The procedure allows all the blue blood returning from the body to bypass the heart and go directly to the lungs to pick up oyxgen. After the now red (oxygenated) blood returns to the heart, the single functional ventricle pumps it to the body. After this procedure, the child will be “pink” and typically have oxygen saturation of more than 90%.
Physicians usually wait until a patient is a few years old or weighs about 30 pounds before performing the Fontan surgery. After recovering and being discharged from the hospital, patients initially have follow-up appointments every several months to make sure they have fully recovered from surgery.
Step 4: Beyond the Fontan
After children have their Fontan operation, they will require ongoing cardiac follow-up throughout life and may require additional procedures or surgeries later in childhood or adulthood to ensure their vital organs are still functioning properly. These patients are at risk for heart rhythm issues, blood clots, Fontan-associated liver disease, kidney dysfunction, and respiratory problems. These problems can develop over time, so it is important for patients followed in our Single Ventricle Follow-Up Clinic to be monitored closely. The clinic provides a centralized place for patients with a failing Fontan to have:
Hepatology (liver) surveillance
Medication changes and adjustments
Fontan exercise consultations
Personalized nutrition consultations
Unfortunately, despite tremendous medical advances, the heart or other vital organs may start to show signs of decreased function at some point in patients’ journeys, which we call “Fontan Failure” because it means that the body is no longer tolerating the Fontan circulation. In addition, because of the inefficiency of the Fontan circulation, the heart may not be able to pump enough blood to the body and vital organs, a condition called heart failure. Failing Fontan care can be provided by the Single Ventricle Center of Excellence Team that works closely with the Pediatric Heart Failure and Heart Transplant Program in the Single Ventricle Follow-Up Clinic. Lurie Children’s is known internationally for this care because of Lurie Children’s physicians’ extensive experience, the support staff’s expertise in their respective areas, and the facilities’ state-of-the art equipment and technology.
The Fontan procedure has changed a lot since it was first introduced in the 1970s. Some adult patients may have an older version of the operation called an aortopulmonary Fontan, rather than the type of Fontan procedure we perform today. Those patients may require a special type of Fontan revision called a “Fontan Conversion Procedure” which converts their anatomy to the more modern version of the Fontan. This often improves problems with the heart rhythm and with the pumping efficiency and may help patients to avoid or delay a heart transplant. The internationally respected Fontan Conversion and Arrhythmia Surgery program at Lurie Children’s is among the largest in the world. Learn about Lurie Children's Fontan Conversion Program.