The liver is one of the most complex organs in the body and it carries out more than 500 functions, including filtering toxins from the blood and regulating cholesterol levels in the blood.
In cases where the liver has been damaged to the point that it cannot perform its normal functions and is likely to fail a liver transplant offers the only hope of long-term survival. The liver can become damaged as a result of illness or infection. A total of 726 liver transplants were carried out in the UK in 2011-12, however, the number of people who need a liver transplant is much higher than the number of livers donated.
In deceased organ donation, which involves transplanting a liver that has been removed from a person who has recently died, the liver remains viable for no more than 12 hours from the time when it was harvested. As a consequence, geographical location can determine who receives a transplanted liver as much as need. However, a team of scientists from Harvard University have now developed a cooling technique to preserve livers prior to transplantation that could help to overcome this problem.
In experiments using rats, livers were preserved for up to four days before then being transplanted. Seven out of twelve rats survived for at least three months. With transplantation after three days all six rats in the experiment survived. The new technique relies on super-cooling. Livers were stored at minus 6 degrees Celsius in a chemical bath that prevented them from freezing, which destroys delicate cell membranes. The livers were then slowly warmed before surgery.
The experiment is the first time that a liver has been successfully transplanted after four days of storage in any species. Although extending the technique to humans would be a challenge, if it were possible it could have a major impact on the system of liver transplantation as livers would be able to reach those people most in need.
The study was reported in the journal Nature Medicine.