Keeping donated livers “alive” with a machine prior to transplants boosts the chances of a successful operation, a landmark trial has found.
Usually livers are kept in ice prior before the surgery, but many become damaged and unusable as a result.
For this study, scientists put them in a perfusion machine, pumping the organs with blood, nutrients and medicines.
More of these “warm” livers went on to be transplanted and showed less damage than the “cold” ones, the trial found.
Scientists said the study could help to reduce the significant proportion of people who die waiting for a new liver and potentially “transform” how organ transplants are carried out.
The randomised controlled trial involved 222 liver transplants in seven European centres.
It compared liver transplants where the organs were first preserved in an ice box with those kept “alive” outside the body using a so-called normothermic perfusion machine.
Out of the 220 transplants scientists analysed, the study found there was 50% less tissue damage in the “warm” livers – a key marker of how likely the organ is to survive as well as the transplant patient themselves.
Scientists were also able to successfully transplant more of the warm livers than cold ones.
Just 16 out of 137 warm livers needed to be discarded compared with 32 out of 133 cold ones, meaning 222 transplants were able to go ahead. All but two were analysed by the team.
Prof Peter Friend, one of the authors of the study in the journal Nature and one of the inventors of the machine, said currently about a third of donated livers could not be used for transplantation due to a range of factors.
These include livers taken from elderly people or those in poor health, which were more likely to fail, damage occurring while the organ was removed from the donor’s body and damage sustained while being kept in ice.
About 20% of patients die while waiting for a liver transplant, he said.
Keeping the liver “alive” outside the body helps it recover from the damage it suffers during the process of being removed from the donor’s body, authors said.
“There’s a huge issue in terms of the [high] number of patients compared to donor organs, and yet we’re not using all of the donor organs that are available,” Prof Friend told the BBC.
“If we can go some way towards utilising the livers that are not transplanted it would have a major impact.”
BBC medical correspondent Fergus Walsh
There are machines that can keep the heart beating and nourished outside the body.
I have witnessed one of these heart-in-a-box machines in operation – and could see – and even touch – a pig’s heart beating under the plastic covers.
There are also machines that can keep kidneys preserved at body temperature.
There has been such significant progress in this field that this trial may signal the beginning of the end of keeping donor organs on ice – although it could be several years before every transplant centre has this technology.