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Fontan Operation

Fontan Operation: What it is, Symptoms, Causes and Risk Factors, Diagnosis, Treatments | National Heart Centre Singapore

Fontan Operation - What is it for

The Fontan operation is the last stage of a series of operations to create a pathway for poor-oxygen blood to bypass one of the ventricles and drain directly into the lungs. This procedure is usually performed on patients who only have one effective ventricle to pump blood to both the body and lungs. 


In a healthy heart, the left side of the heart pumps oxygen-rich blood to the rest of the body while the right side pumps oxygen-poor blood to the lungs. 

The normal heart has 4 pumping chambers, the left and right atria (upper chambers) and the left and right ventricles (lower chambers). The right ventricle pumps oxygen-poor blood to the lungs while the left ventricle pumps oxygen-rich  blood to the body. However, babies with certain complex congenital heart conditions are born with only one functional ventricle while the other one is usually underdeveloped and may exist with a non-functional valve. Since only one ventricle is pumping normally, both oxygen-rich and oxygen-poor blood get mixed in this chamber. As such, the blood that is pumped to the rest of the body has much lower oxygen levels than normal. 

The aim of the Fontan operation is thus to separate the oxygen-poor blood from the oxygen-rich blood. Oxygen-poor blood is directed to the blood vessels leading to the lungs, which allows the single ventricle to only pump oxygen-rich blood to the body. This procedure should increase the blood flow into lungs, reduce the workload of the single ventricle and improve exercise tolerance of patients. 

In most patients with complex congenital heart diseases, the Fontan operation is usually performed during childhood. However, it is possible to find un-operated adults who are suitable for the Fontan operation later on in life. These patients will need careful assessment of their heart and blood circulation before surgery. Most patients will be well for many years after the Fontan operation though there are some patients who may develop complications, especially those who completed the procedure at a later age.

Fontan Operation - Symptoms

Fontan Operation - How to prevent?

Fontan Operation - Causes and Risk Factors

Fontan Operation - Diagnosis

Fontan Operation - Treatments

Fontan Operation - Preparing for surgery

Fontan Operation - Post-surgery care


Possible complications of Fontan operation 

  • Arrhythmias
Arrhythmias (abnormal heart rhythm) may develop and are more likely in those patients operated at a later age. Some types of Fontan operations also carry a higher risk of arrhythmias due to enlargement and scarring of the atrium, causing problem with the heart’s electrical conduction. Treatment options may include medication, insertion of pacemaker and radiofrequency ablation procedure.
  • Protein losing enteropathy (PLE)
Some Fontan patients may develop a condition called Protein-Losing Enteropathy (PLE) where protein is lost through the gut. This is a very serious condition and the exact cause is unknown. Generally, the treatment involves taking medication and for severe cases, a transplant may be necessary.
  • Fluid retention issues
Some patients might have problems with fluid retention in the abdomen or lower part of the legs. 

Post-procedure care


Blood thinning medication 
All patients who have had Fontan operation are prescribed blood-thinning medication by the cardiologist. Some patients may be required to take warfarin, a blood thinning medication which helps to reduce the risk of blood clot formation. These patients will require blood-thinning level (INR- International Normalised Ratio) to be monitored regularly. This medication must not be stopped abruptly without your cardiologist’s instructions. 

Exercise
Simple and moderate exercise – light jogging, cycling, swimming, brisk walking and yoga – may be well tolerated and is encouraged. Regular exercise may improve the general well-being of patients. However, do avoid competitive and contact sports especially for patients on warfarin.

Prevention of endocarditis
Dental care and hygiene is very important in prevention of endocarditis (infection of the inner layer of the heart). Patients are advised to go for regular dental check-up. Antibiotic prophylaxis (taking preventive antibiotics) is needed to prevent endocarditis before any surgical or dental procedures. Antibiotics may also be required for risky procedures such as body piercing or tattooing.

Liver complications
Patients who have had Fontan operation are at risk for liver cirrhosis (hardening of the liver tissues) or even liver tumours. They are referred to the liver specialist who will do regular scans and gastroscopes to monitor their condition. 

Vitamin D
Studies have shown that patients with Fontan operation often have low vitamin D levels and might need oral vitamin D replacement. 

Family planning and pregnancy
It is important to choose a safe and effective contraception, as not all options are suitable. Do discuss the different methods of contraception with the cardiologist.

Women who have undergone the Fontan operation carry a higher risk in pregnancy due to the physiological heart and circulation changes after surgery. In particular, patients who are contemplating pregnancy and also taking warfarin should have a prior discussion with their cardiologist as warfarin can cause serious fetal abnormality.

Additionally, for those who have had the Fontan operation, there is a higher chance of passing the congenital heart defect to their offspring. These patients need careful planning and assessment with close follow-up care jointly by the obstetrician and the cardiologist. Do consult the cardiologist prior to starting a family.  

National Heart Centre Singapore (NHCS) and the Department of Obstetrics & Gynaecology from Singapore General Hospital run a monthly specialised joint Cardiac-Obstetric Clinic on the last Monday morning of the month to see all pregnant patients with heart disease. Over the last 10 years, we have managed 200 to 300 pregnant patients with varying severity of cardiac problems through their pregnancy with successful outcomes.

Employment
It is possible for patients who have undergone the Fontan operation to get a full-time or part-time job. However, they should avoid jobs that require heavy labour and carry a higher risk of injury, especially for patients under warfarin therapy.

Maintaining a healthy lifestyle 
Acquired heart disease such as coronary artery disease and enlargement of the heart will pose additional risk to the Fontan patient’s health. It is important to maintain an overall good health with regular exercise and a well-balanced diet.

Follow-up care
All patients with Fontan operation require life-long follow-up with regular assessments.

  • Updated on 2022-11-13T16:00:00Z

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