Human livers can now be kept alive and functioning outside the body on a new machine, British scientists reveal in a world first which they say will double the numbers of livers available for transplant.
LONDON, ENGLAND, UK (MARCH 15, 2013) (REUTERS) - A donated human liver has been kept alive, warm and functioning outside a human being on a newly-developed machine and then successfully transplanted into patients in a medical world first.
A British team of doctors, engineers and surgeons announcing the achievement on Friday (March 15) said it could be common practice in hospitals across the developed world within a few years, up to doubling the number of livers available for transplant.
So far the procedure has been performed on two patients on Britain's liver transplant waiting list and both are making excellent recoveries, the medical team told a news conference.
"We have taken something which used to be very simple technology, placing an organ on ice and around it recreated the environment that it would normally encounter within the human body," said Constantin Coussios, a professor of biomedical engineering at Oxford University and one of the machine's co-inventors.
"A warm preserved organ is very, very different to something stored on ice. It has to be kept warm, it is now breathing and burning sugar just as it would within the body, so it needs to be fed, it needs to be oxygenated, blood needs to be circulated around it," he said.
Currently livers destined for transplant are kept "on ice" in a process which cools them to slow down their metabolism and does not keep them functioning as they would inside a body.
This system has worked for several decades, but can also often lead to livers becoming damaged and rendered unfit for use in patients who need them.
Surgeons say keeping livers "on ice" beyond 14 hours starts becoming risky, although they can last up to 20 hours.
Hepatitis infection, alcohol abuse and drug-induced cholestasis - a blockage in the flow of bile from the liver - can all cause liver failure. Some patients with liver cancer can also benefit from a transplant.
Experts say up to a quarter of these patients die while they are waiting. At the same time, more than 2,000 livers are discarded every year because they are either damaged by oxygen deprivation or do not survive the cold preservation process.
The new technology, developed by Coussios together with Peter Friend, director of the Oxford Transplant Centre, preserves the liver at body temperature and "perfuses" it - supplying it with oxygenated red blood cells to keep it alive.
The device can keep a liver functioning normally - just as if in a person, with blood circulating through its capillaries and bile being produced - outside the body for 24 hours or more.
"Our expectation is that the liver will function more rapidly and more reliably," said Professor Nigel Heaton, liver transplant surgeon at King's College Hospital who performed the two trial surgeries.
"Effectively because the organ hasn't been cooled down and then has to be re-warmed, but is coming into the patient straight from a warm environment, it would tend to work from the very moment it is implanted," said Coussios.
The results from the first two transplants using the new technology, carried out inLondon last month, suggest the device could be useful for all patients needing liver transplants.
The new device could also mean livers which would otherwise be discarded as unfit for transplantation could be preserved and made viable - potentially as much as doubling the number of organs available for transplant.
The first person to receive a transplanted liver kept alive on the OrganOx system was 62-year-old Briton Ian Christie. He is still recovering from the surgery but said in a statement he was getting better day by day. "I just feel so alive," he said.
Christie was told last year he had cirrhosis of the liver and had only 12 to 18 months to live unless he got a transplant. "I was placed on the waiting list but...I was very worried."
Having been through the surgery, he said: "I feel better than I've felt for 10 to 15 years, even allowing for the pain and wound that's got to heal."
The team now plans to run a pilot trial with 20 more liver transplant patients at KCH. Coussios said successful results of that trial would allow them to apply for marketing authority, meaning the device could be on the market by as early as 2014.