'Supercooled' Livers Help to Extend Preservation of Donated Organs

Keeping donated organs safe for transplantation can be a quite complicated. For instance, once an organ is cut off from oxygen, it immediately begins to deteriorate. However, cooling can typically help reduce deterioration by up to 12 hours. Now, a recent study in published in the journal Nature Medicine reveals that a new system could extend preservation by up to four days.

"To our knowledge, this is the longest preservation time with subsequent successful transplantation achieved to date," said Korkut Uygun, PhD, of the MGH Center for Engineering in Medicine (MGH-CEM), co-senior author of the report. "If we can do this with human organs, we could share organs globally, helping to alleviate the worldwide organ shortage."

For the study, researchers worked to transplant rat livers that were preserved for four days, thanks to a process called "supercooling." The technique works to extend organs' preservation by slowing metabolism. However, the process is not without its problems.

For instance, extreme cooling could also lead to damaged organ tissues. To reduce this risk, researchers advice MGH-CEM protocol that involves using polyethylene glycol (PEG), which protects membranes, and a glucose derivative known as 3-OMG that's used in liver cells.

After the organs were removed from the donors, the livers were then attached to a machine perfusion system that supports basic body function. They were stored with 3-OMG and flushed with UW and PEG solutions and stored for either 72 or 96 hours at 21 degrees Fahrenheit before the temperature was decreased for three hours in room temperature solutions.

"This ability to assess the livers prior to transplantation allows us to determine whether the supercooled organ is still good enough for transplantation," said study co-author Bote Bruinsma, MSc, of the MGH-CEM. "Even among the livers preserved for four days, if we had only used those in which oxygen uptake, bile production and the flow of perfusion solution were good, we would have achieved 100 percent survival."

By reducing the damage that can occur during preservation and transportation, researchers said they hope to reduce the long waiting lists of transplants around the globe.