Scientists are saying they have found a way to triple the amount of time a human liver can be safely stored, giving doctors and transplant recipients far more flexibility in pursuing treatment.
The current method stores livers at just four degrees Celsius. This, doctors say, is the most appropriate temperature for storing a liver before irreparable damage can occur from cells freezing. But at this temperature, these vital organs can only remain viable for approximately nine hours.
For the new technique, medical technicians can “supercool” these organs—without the use of ice storage—to an astonishing temperature of negative four (-4) degrees Celsius without jeopardizing tissue integrity. This means transplant livers can be saved, stored, and transported, for up to 27 hours.
Co-lead study author Reinier de Vries explains, “With supercooling, as the volume increases it becomes exponentially more difficult to prevent ice formation at sub-zero temperatures. Before, there were a lot of experts who said, ‘well this is amazing in small rats, but it will not work in human organs,’ and now we have successfully scaled it up 200 times from rat to human livers using a combination of technologies.”
Indeed after restoring each of the “supercooled” livers, they functioned as expected. These expectations were based on lab tests that analyzed things like oxygen use, bile production, and lactate metabolism in a simulated human setting. In addition—and, perhaps, more importantly, these livers also survived a “simulated transplant” when restored to temperature and connected to an artificial blood supply.
Of course, none of these test livers were used for actual transplant but did survive 27 hours outside the human body. After simulating life conditions to test for viability, the researchers did not continue observing viability. This is important, as de Vries believes this new technique is only the beginning of more discoveries. The next step, actually, would be live transplants with animals, using this elongated “supercooling” process.