Donated livers are a scant and precious resource, both in England and around the world.
Therefore, the assessment process that decides who can have a liver transplant is a lot stricter than for most medical treatments.
Under UK regulations you are usually only considered a suitable candidate for a liver transplant if:
- without a liver transplant, it is highly likely that your expected lifespan would be shorter than normal or your quality of life is so poor as to be intolerable, and
- it is expected that you have at least a 50% chance of surviving for at least five years after the transplant with an acceptable quality of life
Calculating the risk of death
Transplant centres use a scoring system to calculate the risk of a person dying if a transplant is not performed.
In the UK, the system is known as UKELD (United Kingdom Model for End-Stage Liver Disease).
The UKELD is based on the results of four tests:
- the INR test – a blood test that assesses whether your blood is clotting normally (excessive liver damage can make it harder for the blood to clot)
- serum creatinine test – a blood test that checks whether your kidneys are filtering a waste product known as creatinine from your blood (impaired kidney function is often associated with severe liver disease)
- serum bilirubin test – a test used to measure levels of a waste product called bilirubin in your blood (one of the liver’s main functions is to remove bilirubin from your blood, so high levels would indicate significant loss of liver function)
- serum sodium test – a test used to measure levels of sodium in your blood (unusually low levels are often the result of scarring of the liver)
These scores are then multiplied and added together in a certain way to produce a final score.
A UKELD score of 49 would mean that you have a 9% chance of dying in the next year. It is the minimum score you would need to be added to the waiting list for a liver transplant. The higher your UKELD score and your risk of death, the higher up the waiting list you will be.
Assessing quality of life
Assessing your quality of life can be a subjective process. Different transplant centres may have different criteria or opinions.
However, most experts in liver disease would accept that the following signs and symptoms represent a decline in quality of life that many people would find intolerable:
- swelling of the abdomen due to a build-up of fluid (known as ascites), which fails to respond to treatment
- persistent and debilitating shortness of breath
- damage to the liver that is now affecting the normal workings of the brain (hepatic encephalopathy), resulting in mental confusion, reduced levels of consciousness and, in the most serious of cases, coma
- persistent itchiness of the skin that fails to respond to treatment (for reasons that are still unclear, itchy skin is a common symptom of liver disease)
- persistent liver pain that cannot be controlled by treatment
Estimating survival rates
There is no UKELD-style scoring device to estimate your likelihood of surviving for at least five years after a liver transplant.
The assessment of your likely survival rate is based on your individual circumstances and associated factors, such as:
- your age (although transplants have been successful in people aged over 70)
- whether you have another serious health condition, such as heart disease
- how likely a donated liver would remain healthy after the transplant
- your ability to cope (physically and mentally) with the effects of surgery and the side effects associated with immunosuppressant medication
A number of tests will also be carried out to assess your health and your likelihood of survival. These tests are described below.
- Chest X-rays can help to determine how well your heart and lungs are working.
- Lung function tests measure how much oxygen is moving in and out of your lungs.
- An electrocardiogram (ECG) measures the electrical activity of your heart using electrodes placed on your skin, and a computer.
- Pulse oximetry measures the amount of oxygen in your blood using a sensor placed on your fingertip or toe.
- Duplex ultrasonography (a type of ultrasound scan) shows how blood is flowing through the body; it can be a useful way of diagnosing conditions that can affect your blood vessels such as atherosclerosis (hardening and narrowing of the arteries).
- Coronary angiography (a dye that shows up on X-rays is injected into the blood vessels near your heart) can often detect problems with your heart, such as coronary heart disease.
Contraindications
'Contraindications' are the reasons why a person should not have a particular treatment because it would not be safe or effective.
There are two types of contraindications:
- an absolute contraindication – when a treatment should never be given whatever the circumstance
- a relative contraindication – where it is usually not recommended that a treatment be given, though there will be times when an exception can be made
Absolute contraindications
Absolute contraindications for liver transplants are listed below.
- Being HIV positive.
- Having irreversible brain damage.
- Having an infection – it would be necessary to wait for the infection to pass.
- Having multiple organ failure that would not be helped with a liver transplant.
- Having cancer in another part of the body (with the exception of skin cancer).
- Abusing alcohol – most transplant centres only consider a person for transplant if they have not had alcohol for at least three months.
- Abusing drugs – most transplant centres would only consider a person for transplant if they had attended a drug rehabilitation course and had remained free from drugs for at least six months (some transplant centres will accept people who are currently taking the heroin substitute methadone).
- Having a serious heart and/or lung condition such as heart failure (where the heart is unable to pump blood properly around the body) or chronic obstructive pulmonary disease (COPD), a serious lung condition that can cause breathing difficulties.
- Having a serious mental health or behavioural condition that means you would be unlikely to be able to comply with the medical recommendations regarding life after a liver transplant. Examples of such conditions include psychosis (where a person cannot tell the difference between reality and their imagination) or bipolar disorder (manic depression).
Relative contraindications
Relative contraindications for liver transplant include:
- kidney failure – where the kidneys have lost most or all of their function
- extensive weight loss due to poor health and/or malnutrition
- advanced liver cancer – by the time the cancer has spread beyond the liver into surrounding tissue, it is usually too late to cure the cancer with a transplant
- an active hepatitis B infection that is not responding to medication
- a blood clot in one of the main blood vessels near the liver
Having one of these relative contraindications does not automatically mean a transplant cannot go ahead. But two or more contraindications would make it unlikely.
