Supercooled Donor Livers last 3-Times Longer for Transplants

Organ donations save so many lives. What was once a medical rarity has become commonplace. Kidneys are the most commonly transplanted organ followed by livers.

Donated Organs only stay viable for a few hours on ice at around 4 degrees Celsius (39.2 degrees Fahrenheit) according to a Harvard Medical School news release, because the ice can begin to damage the tissue. Supercooling organs at much lower temperatures could greatly extend the time that they are viable.

There are many more people who need transplants and are waiting on lists then organs that are available. There are currently over 113,000 people waiting for transplants in the US. Sometimes there isn’t a suitable match found for a patient or an organ is available but there isn’t a matched patient close enough to use it, so thousands of organs are discarded every year.

Now, researchers in a Harvard Medical School study that was conducted at Massachusetts General Hospital in Boston have developed a new technique that uses chemicals that prevent organs from freezing at subzero temperatures. In a report published in September 2019 in Nature Biotechnology, they preserved five  human livers in this new supercool storage system for three times as long – from nine to 27 hours – as keeping the livers on ice.

The chemicals used included trehalose and glycerol, to stave off ice formation and to protect the cells at this very low, –4 degrees Celsius (24.8 percent Fahrenheit), temperature. The chemicals were administered by using a machine perfusion system according to the study. The device is essentially, “an artificial body for the liver,” said the study’s co-author Reinier de Vries, a medical doctor and mechanical engineer at Harvard Medical School and Massachusetts General Hospital in Boston.

The device was scaled up from one designed to work on the livers of small rats in a previous study.

The livers were sealed in a bag and stored in a special cooler for 20 hours and then the chemicals were flushed out and the organs were warmed to room temperature. The entire process took 27 hours.

During this experimentation with the livers, we got absolutely no ice formation for the duration of storage,” said study coauthor Shannon Tessier, a biomedical engineer also at Harvard and Massachusetts General. Ina procedure that simulated a transplant, the livers functioned completely normal.

The extra time the technique can buy could make the difference between success and failure of a liver transplant, Tessier said. “A lot of times when an organ becomes available, there may not be a good match nearby—so in terms of allocation, when you add that extra amount of time, that means you can search a wider distance which means you have a better chance of not only finding a good match, but an excellent match.”

The next step according to Tessier will be to use the supercooling set up on large animal livers and then to transplant them to prove that the process works before any clinical trials are possible.

This kind of deep-chill technology “would be huge for transplantation,” Jedediah Lewis, president and CEO of the Organ Preservation Alliance in Berkeley, California told Science News.

Increasing the time that an organ can be successfully transplanted will allow more organs to get to the people who need them. It will also decrease the cost of the procedure as organs may not have to be airlifted to patients and that will be a big incentive for hospitals and insurance companies. This new supercooling method has the potential to save many lives.