Chilled donor organs last longer

Chilled donor organs last longer

07/01/2014

Thousands of people are waiting for a life-saving transplant. A big problem with medicine is that donor organs can only be kept for a short time. US researchers have now succeeded in significantly extending the shelf life of rat livers.

Extend shelf life of donor organs

Thousands of patients are waiting for a life-saving transplant in Germany. But matching donor organs are scarce. In addition, the time factor is a problem because a removed organ must be transplanted relatively quickly to continue to function. In the future, a new process could dramatically extend the shelf life of donor organs. US physicians have been able to preserve livers for four days with a sophisticated, extreme-cooling method, but only in rats so far. The cooling of the organs will be for this „supercooling“ combined with the supply of nutrients and oxygen. As the researchers around Korkut Uygun from Harvard Medical School in Boston in the journal „Nature Medicine“ could write something could be defused, if the success can be transferred to humans.

Falling donation readiness and short shelf life

Hundreds of thousands of people are waiting worldwide for a donor organ. In Germany there are about 11,000 seriously ill patients who could possibly save a transplant. But the willingness to donate is steadily decreasing in this country. Although a recent survey by the Federal Center for Health Education (BZgA) found that 68 percent of Germans agree to donate their organs after death, only 28 percent of Germans have an organ donor card. In addition to the lack of donors, there is also the problem of the short shelf life of organs removed in transplantation medicine. These are cooled since the 1980s at temperatures around the freezing point in solutions that reduce the metabolism. As the US researchers write, you can get donor livers up to twelve hours.

Cooling organs also carries risks

If this time span could be extended, recipients from a larger radius could be selected and better prepared for the operation. Cooling of organs, however, also carries a number of risks, from ice formation to damage to cells. The US researchers have now tested a method for rats that significantly extends the preservation of livers. They first attached the removed organs to a perfusion system, which provides the tissue with oxygen and nutrients. In addition, the physicians treated the livers for cold protection with the glucose compound 3-OMG (3-O-methyl-D-glucose) and cooled them with polyethylene glycol as antifreeze and another solution to four degrees Celsius. Finally, they stored the organs at minus six degrees Celsius for 72 or 96 hours, before gradually raising the temperature again.

Liver transplantable for four days

All recipient animals survived for at least three months after 72 hours of storage. The survival rate for the preservation of 96 hours was only 58 percent. Co-author Bote Bruinsma is quoted in a statement from the University: „Even among the four days of stored livers, we would have achieved a survival rate of 100 percent if we had only taken those in which oxygen uptake, fluid formation and perfusion flow were good.“ In addition, the authors write: „To our best knowledge, this is the first preservation technique that keeps livers transplantable after four days.“

Long way to the application on humans

They emphasized that the transferability of the method to humans would increase the number of successful liver transplants. „The longer we can store donor organs, the greater the chance that a patient will get the best possible match and that doctors and recipients are optimally prepared for the operation“, Rosemarie Hunziker of the National US Institutes of Health (NIH) said. „This is a crucial step to improve organ storage for transplantation.“ However, it is still a long way to the application to humans, as the researchers acknowledge. On the one hand, this is because human liver cells differ from those in rodents. In addition, the risk of frost damage is due simply because human livers are much larger than those of rats.

(Ad)