A donated liver may be a whole liver, a reduced liver or a split liver.
- A whole liver is exactly as you’d imagine, the entire liver.
- A reduced liver is when only a part of the liver is used. This is more common in liver transplants in children.
- A split liver is when either a right or left lobe is used. Usually, the larger right lobe transplants are used for adult recipients, and the smaller left lobe is used for children, or an adult with a small body size.
Both a reduced and split liver will grow over time to a full-sized liver.
Most donor livers in the UK come from people who have died. These people will all have died from a terrible brain injury. For example from a stroke or physical damage from an accident. There are two types of donor depending on how it was determined that they had died.
Donation after brain death (DBD) means the person has been declared dead through brain testing. When this happens, the person will still be on a machine to help them breath and their heart will still be beating. So their liver is still getting blood and oxygen until the moment it is removed.
Donation after circulatory death (DCD) means the person could not be tested for brain death. Instead they were declared dead after their heart stopped beating. This can potentially have more risk. Because the supply of blood, oxygen and essential nutrients to the liver is interrupted when the donor’s heart stops beating. So the cells in the liver can start to deteriorate. However, livers can be preserved in what’s called a perfusion machine and this technology is still developing. You might like to ask your transplant team what they use in your centre.
You can find out more about perfusion machines and the different types of donor by reading our blog here.
There are other risks to consider. Some livers are likely to work for longer than others, for example because of health problems the donor had. It is also possible for diseases to be passed to you through a donor liver. All donated livers carry some risk, but generally this is much lower than the risks of your liver disease.
Your transplant team will talk you through your choices and explain what these could mean for you. This is your personal choice and they will support you whatever you decide to do.
A healthy liver is the only organ in the body that can (under the right circumstances) re-grow a lost part, which is why a living donor can donate part of their liver.
The person will need to have a number of tests before they can be considered to make sure they’re healthy enough to donate and their liver is working properly. These include:
- blood tests
- scans and X-rays
- urine tests
- heart tests
- liver tests
Living donors will also have a psychological assessment because donating part of your liver is a big decision, which can be an emotional process. The assessors must ensure there isn’t a risk of harm to their mental health.
The living donor will also be assessed by an independent assessor on behalf of the Human Tissue Authority to discuss the reasons for donating and to make sure they understand the process. The Human Tissue Authority will need to approve the donation in order for the operation to happen.
A Living Donor Coordinator will guide them through the entire process and be on hand to answer any questions.
DBD livers are matched to people using a set of criteria called the Transplant Benefit Score (TBS).
The TBS will take into account 7 characteristics from the donor, which are matched with 21 characteristics from you. Donor characteristics include things like:
- their age
- existing health conditions, such as diabetes
- blood group
Things about you that will be considered will include:
- your age
- health conditions
- results of tests that were done as part of your transplant assessment
Your ethnic background, and the ethnic background of the donor are not part of the TBS criteria. The donor and recipient do not need to have the same ethnic backgrounds because liver transplants require a less specific match than some other types of transplant.
When a donated liver becomes available, it will go to the person with the highest TBS score. But the final decision to accept the organ still rests with you and your transplant surgeon.
DCD livers are matched to people by transplant teams based on things including your blood group, size, weight, need and waiting time.
The waiting list isn’t like being in a queue where everyone is seen in a set order. The liver is matched to the person who needs it most at that time and who will get the most benefit from that particular liver. The right liver goes to the right person at the right time.