Surgeons externally attached a pig liver to a brain-dead human body and watched it successfully filter blood, a move to eventually try the technique in patients with liver failure.
The University of Pennsylvania announced the new experiment on Thursday, a different spin on animal-to-human organ transplants. In this case, the pig liver was used outside the donated body, not inside it – a way to create a “bridge” for failing livers to do the organ’s blood-cleansing work externally, just like dialysis for failing kidneys.
Animal-to-human transplants, called xenotransplants, have failed for decades because people’s immune systems rejected the foreign tissue. Now scientists are trying again with pigs whose organs have been genetically modified to be more human.
In recent years, kidneys from genetically modified pigs have been temporarily transplanted into brain-dead donors to see how well they function, and two men have received heart transplants from pigs, although both died within months.
The US Food and Drug Administration is considering allowing a small number of Americans who need a new organ to volunteer for rigorous studies of either pig hearts or kidneys.
Some researchers also want to use pig livers. A liver has different complexities than kidneys and hearts: it filters blood, removes waste and produces substances needed for other body functions. About 10,000 people are currently on the US waiting list for a liver transplant.
In the Penn experiment, researchers attached a liver from a pig — one genetically modified by eGenesis — to a device made by OrganOx that usually helps preserve donated human livers before transplant.
The family of the deceased, whose organs were not suitable for donation, offered the body for the research. Machines circulated the body’s blood.
The experiment, carried out last month, filtered blood through the pig liver device for 72 hours. In a statement, the Penn team reported that the donor’s body remained stable and the pig liver showed no signs of damage.
There is a lot of work to develop liver dialysis-like machines, and experiments with pig livers were tried years ago — before today’s more advanced genetic techniques, said Dr. Parsia Vagefi of UT Southwestern Medical Center, who was not involved in the new experiment, but is close. see xenotransplantation research.
“I applaud them for pushing this forward,” Vagefi said, calling this combination pig-device approach an intriguing step in efforts to better care for liver failure.
