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How scientists keep livers alive for one week outside human body


A surgeon connects the donor liver to the perfusion machine CREDIT: USZ

The chances of losing patients with severe liver diseases or cancer to death are set to decline as scientists have developed a machine that repairs injured human livers and keep them alive outside the body for one week.

The new perfusion technology, which is a major breakthrough in transplant medicine, may increase the number of available organs for transplantation and save the lives of many patients suffering from severe liver disease or a variety of cancers.

Global estimate shows that 844 million people have Chronic Liver Diseases CLD), with a mortality rate of two million deaths yearly, according to the National Center for Biotechnology Information (NCBI).

Also, according to the National statistics in the United Kingdom, liver diseases have been ranked as the fifth most common cause of death, killing around 11,000 people in England each year and has increased by 25 percent in the last decade, due to poor diet.

Another estimate recognise the liver disease as the second leading cause of mortality among all digestive diseases in the United States.

The NCBI further estimates that recent trends in morbidity and mortality indicate that patients with acute or chronic liver failure constitute five percent of all hospitalisations for cirrhosis.

Meanwhile, for those who have end-stage liver disease, transplant is the only option if they must survive.

According to experts, around 400 people are waiting in Britain for a liver at any one time, but one in 10 dies before an organ becomes available, or will need to be removed from the transplant list because their condition has deteriorated to the point where an operation is no longer possible.

But with the new innovation, researchers say the machine can save many lives of patients suffering from severe liver disease or a variety of cancers, and give surgeons more time to check that the organ used is the most suitable.

Until now, livers could be stored safely outside the body for only about eight to 10 hours on the ice, or 24 hours if hooked up to a special perfusion device, severely limiting how far they can be transported.

In 2018, there were about 975 liver transplants carried out, but a further 599 organs were rejected, meaning four in every 10 donated is wasted. But the new system could allow hundreds of discarded livers to be used.

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich in Switzerland, who developed the machine, said donor livers can also be kept alive for a week and repaired using the machine, which has the potential to ‘dramatically improve’ organ transplantation in Britain.

The researchers in University of Zurich further proved that the machine not only keeps the organs alive for seven times as long, but also repairs damage in livers that would normally have been rejected.

This, the researchers said, means that around 60 percent of diseased or injured livers could now be used, as the new machine keeps the liver alive by mimicking most core body functions close to physiology.

The corresponding study, which was published in the scientific journal Nature Biotechnology, showed that injured livers could regain full function using the machine.

The inaugural study showed that six of ten perfused poor-quality human livers, declined for transplantation by all centers in Europe, recovered to full function within one week of perfusion on the machine.

The next step will be to use these organs for transplantation. The proposed technology opens a large avenue for many applications offering a new life for many patients with end-stage liver disease or cancer, according to scientists.

Chairman of the Department of Surgery and Transplantation at the University Hospital Zurich (USZ), Prof. Pierre-Alain Clavien explained that when the project Liver4Life started in 2015, livers could only be kept on the machine for 12 hours.

Clavien said the seven-day successful perfusion of poor-quality livers now allows for a wide range of strategies, which include, repair of preexisting injury, cleaning of fat deposits in the liver or even regeneration of partial livers.

“The success of this unique perfusion system – developed over a four-year period by a group of surgeons, biologists, and engineers – paves the way for many new applications in transplantation and cancer medicine helping patients with no liver grafts available”

“The idea is that we trick the liver, and let it believe it is still in the body. We’ve spent four years trialling this in pigs and now we are ready to use these organs in humans, hopefully, this year.

“In the future, for patients with liver cancer, we may be able to take a section of the liver, grow it bigger and transplant it back into the patient. And it should work for other organs as well.”

Also commenting on the research, Chief Executive at The British Liver Trust, Pamela Healy, said: “Sadly, there continues to be a shortage of livers viable for transplant and hundreds of people die each year while on the waiting list.

“This device has the potential to dramatically improve transplant outcomes, allowing livers that were previously thought to be unsuitable to be used and increase the time that livers are able to be kept.

“Ultimately, this could lead to a reduction in waiting list times and mortality rates from advanced liver disease.”
Medical Director of Organ Donation and Transplantation for NHS Blood and Transplant, Prof. John Forsythe, said: “To be able to keep a liver functioning for a week is amazing, it allows time for natural recovery of the organ as well as medical interventions which could make an initially unusable organ, transplantable.

“There are currently 408 patients, including 38 children, waiting for a liver transplant in the UK. With the law around organ donation changing later this year in both England and Scotland and research like this, we hope to help more of these patients receive a lifesaving gift.”

Explaining the project further, Professor of Process Engineering at ETH Zurich, Philipp Rudolf von Rohr, said: “The Liver4Life project was developed under the umbrella of Wyss Zurich institute, which brought together the highly specialized technical know-how and biomedical knowledge of experts from the University Hospital Zurich (USZ), ETH Zurich and the University of Zurich (UZH).

On the challenges faced, Rohr said: “The biggest challenge in the initial phase of our project was to find a common language that would allow communication between the clinicians and engineers.”

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