More than 30,000 people in Europe and the United States are waiting for a live-saving liver transplant, 25 percent of which will die on the waiting list. But with current transplant methods, 2,000 donated livers are discarded when they are either damaged by oxygen deprivation or don’t survive the cooling process.
Donor organs are put on ice until they are transplanted in order to slow their metabolism, but the process often damages the organs, rendering them unusable. A new technology out of Britain promises to revolutionize the transplant process by circulating red blood cells through donated organs, allowing them to remain warm until they can be transplanted. Livers, for example, function normally while in the machine, regain color and produce bile. While livers must be transplanted within 12 hours of extraction under current methods, the technology can preserve them outside the human body for at least 24 hours.
Scientists are currently conducting a clinical trial at the liver transplant center at King’s College Hospital in the UK. There they have connected donated human livers to the new device, which raises their temperature to 98.6 degrees Fahrenheit. Oxygenated red blood cells are then circulated through the livers’ capillaries and the organs function normally while attached to the machine. Using this process, two livers were successfully transplanted into study participants last month.
“These first clinical cases confirm that we can support human livers outside the body, keep them alive and functioning on our machine and then, hours later, successfully transplant them into a patient,” said one of the machine’s inventors, Oxford engineering professor Constantin Coussious. “The device is the very first completely automated liver perfusion device of its kind: the organ is perfused with oxygenated red blood cells at normal body temperature, just as it would be inside the body, and can for example be observed making bile, which makes it an extraordinary feat of engineering.”
Cousious said watching the machine work, when a cold grey liver grew flushed with color once attached and began functioning as it would in the body, was “astounding.
“What was even more astounding was to see the same liver transplanted into a patient who is now walking around.”
While the two pilot transplants only preserved the livers for as long as 10 hours, researchers have conducted other experiments on the machine that preserved functioning organs for as long as 24 hours. The additional time allotted to surgeons would open up new options for transplant patients.
“There is always huge pressure to get a donated liver to the right person within a very short space of time,” said King’s’ College Hospital consultant liver transplant surgeon Wayel Jassem, who performed the pilot operations. “For the first time, we now have a device that is designed specifically to give us extra time to test the liver, to help maximize the chances of the recipient having a successful outcome. This technology has the potential to be hugely significant, and could make more livers available for transplant, and in turn save lives.”
The initial King’s College Hospital trial of 20 patients is currently underway, with almost double on the waiting list. Additional trials involving 300 patients will also be conducted to test the technology against conventional treatments and gauge how well the device improves poor-quality organs. Ultimately, the Oxford team believes the technology could lead to double the number of transplants in the future, not only involving the liver, but also pancreas, kidney, bowel and lungs.