Fontan associated liver disease FALD
What is it? What does it mean?
The normal heart has four chambers two of which are pumps or ventricles. The pump on the right-side pumps blue blood to the lungs where it picks up oxygen. The pump on the left works at a higher-pressure pumping oxygen filled red blood around the body.
Patients with a Fontan circulation only have one pump (single ventricle). They typically undergo several operations with the final one being the Fontan surgery. This surgery enables the one pumping chamber, to pump oxygen filled blood around the body. The blood that needs to return to the lungs, to pick up oxygen, will need to flow there without a pump behind it. This is the basis of the Fontan circulation.
Because there is no pump driving the blood to the lungs it moves slowly, if the resistance to blood flow in the lung blood vessels is high it makes it difficult for the blood to flow to the lungs. This creates a ‘back’ pressure throughout the body (like a traffic jam), to the gut and liver. It can also cause back pressure upwards through the chest, head and neck which can affect breathing and cause headaches. In certain cases, people with a Fontan circulation appear cyanosed (blue) at times, not everyone with a Fontan circulation is blue.
Cardiac teams will try to reduce the back pressure with medications and by inserting a fenestration in the Fontan heart during surgery, which acts a pressure relief valve. As the heart grows the fenestration often closes naturally or is closed surgically.
The liver is an essential organ, performing multiple functions necessary to sustain life. It is also a gland because it makes proteins and hormones that other parts of the body need. It is situated under the ribs on the right side of the body.
The liver has many roles including:
- removing toxins (harmful substances) from the blood.
- removing old red blood cells.
- producing bile, a fluid that helps the body digest (break down) food.
- metabolizing proteins, carbohydrates, and fats so your body can use them.
- producing substances to help blood clot.
- regulating the amount of blood in the body.
- storing energy in form of glucagon and vitamins to be used by the body later.
How is the Liver affected by the Fontan Circulation?
In Fontan patients the liver can become congested because there is no right sided heart pump to keep blood moving through it smoothly. It happens in all patients with a Fontan circulation but the degree to which it happens can vary.
Fortunately, the Liver is a very forgiving organ so even though congestion happens in most cases it will cope.
The high pressure in a Fontan circulation affects the liver in a variety of different ways, the term used to describe these effects is Fontan Associated Liver Disease, FALD.
This happens when the Fontan circulation causes abnormal blood flow characteristics in the liver which over time will result in liver fibrosis, this causes the liver to form a lot of dead scar tissue.
Over time fibrosis can become permanent (cirrhosis); this may affect how well the liver is able to do its job. It can be detected on blood tests and scans of the liver.
Also, the changes in the liver can cause fluid to accumulate in the abdomen, this is called ascites
Abnormalities in the liver can lead to pressure on the spleen (an organ in the abdomen which helps the immune system to work).
In some patients, abnormal growth of the liver cells can occur which often appear as ‘lesions’ on scans. These lesions can be benign (non-cancerous) but in a small number of cases a cancer can develop in the liver (this is important to find early, as prompt treatment with either keyhole or open surgical procedures can be curative.
Here we will try to explain what surveillance and monitoring should take place
The effect of the high pressure a Fontan circulation creates in the body’s organs needs to be monitored at regular intervals. Research at different congenital cardiac centres has shown that over time organs begin to struggle to cope with this higher pressure, especially the liver.
It is for this reason that people with a single ventricle have routine observation of their Fontan circulation and their liver.
How often should the liver be monitored?
Each cardiac centres monitoring plan is slightly different but in most cases children’s heart centres monitoring of the liver starts at the age of fourteen or ten years after the Fontan
In the adult clinic, screening is likely to be more often, most typically once a year but in some cases, it may be more frequent.
If any issues are identified at the liver screening in adult clinic, then the cardiac team will refer for expert advice to a liver team, this team are known as ‘hepatologists.’ They will perform any tests or additional scans needed to monitor the liver.
As mentioned before the type of tests you undergo will depend on your individual cardiac centres. Tests may include:
Blood tests to look at your blood counts, kidney and liver function, iron levels and how well your blood can clot.
This is a scan like your echocardiogram, where you have ‘jelly’ on your abdomen. The scan then looks at the organs you have in your abdomen, specifically your liver. It looks at where your liver is in your abdomen as some people can have their liver on their left side. It looks at the shape and size of the liver. This scan will also check your kidneys and pancreas. It takes about 15-20minutes.
Fibro scan or elastography
This is a specific scan done on the liver. You lie on a bed in the clinic, jelly is placed on a probe, then placed on your skin near your liver to take pictures, it feels funny like someone is giving you a ‘tickle.’ A fibro scan looks to see how well your liver moves, if it is ‘stiff’ or ’wobbly,’ it also looks at the pressure in your liver which is always higher in people with a Fontan circulation. It tells your medical team how well your liver is coping with your Fontan circulation. It takes about 5-10 minutes.
MRI or CT of the liver
This is not done for all patients. It may be done if the abdominal ultrasound cannot provide enough information or if you are preparing for an operation or being assessed for heart transplant. The images taken will give your team a more in depth look at the liver as well as your heart and Fontan circulation, and any extra blood vessels you might have
And your normal heart Investigations
The cardiac team will perform:
- Twelve lead ECG – electrocardiogram. This looks at the rate and rhythm of your heart
- ECHO- echocardiogram. Looks at the heart function and how well your Fontan circulation is working.
They take between 15 and 30mins.
Sometimes one or all these tests can show us that your liver is struggling or not coping very well with your Fontan circulation. If this is the case your medical team will explain to you that they have found, how they are going to monitor it and what you need to do to look after your heart and liver in the future.
Medical Research Medical teams in the UK are working together to create a clear FALD pathway. This will mean that routine monitoring tests will begin at the same age for all patients and the tests will be the same in all units.
Is there anything I can do to help keep my child’s or my liver healthy?
People with a Fontan circulation all have a risk of liver disease, and it may not be possible to completely control any changes caused by their circulation. However, it is always helpful to keep as fit as possible to help the Fontan circulation and any of the organs it might affect.
Maintain a healthy weight. Excessive weight puts a strain on the heart and the liver.
Eat a balanced diet.
Exercise regularly. Within the exercise plan set out by your cardiac team.
Drink alcohol responsibly. Alcoholic beverages can create many health problems. They can damage or destroy liver cells and scar your liver.
Avoid the use of illicit drugs. prescribed or pharmacy approved medication can still cause some damage to the liver too.
Practice safe sex. Unprotected sex or sex with multiple partners increases your risk of hepatitis B and hepatitis C.
Wash your hands. Use soap and warm water immediately after using the bathroom, when you have changed a diaper, and before preparing or eating food.
Follow directions on all medications. For example, Paracetamol is a good pain killer if you keep within the recommended doses. If you take too much it can affect the liver
Get vaccinated. There are vaccines for hepatitis A and hepatitis B.
Who should I ask if I have questions?
Always feel free to ask questions of your cardiac team or if you have been referred to them your liver team.
Lorna Carruthers RGN, BSc Practice Development
ACHD Nurse Specialist and SVH Adult Service lead for Little Hearts Matter
Dr Louise Coats
Consultant Adult congenital heart disease cardiologist at the Freeman Hospital in Newcastle.
Suzie Hutchinson RGN, RSCN
Chief Executive and Service Lead for Little Hearts Matter
Dr Paul Clift
Consultant cardiologist at University Hospitals Birmingham