A new study involving pigs and baboons could mean big news for humans downs the road. Researchers successfully implanted pig hearts into baboons, and two of the recipients lived for six months before being euthanized, reports Scientific American. Writing in Nature, the researchers from Germany, Sweden, and Switzerland call the development a "milestone" for cross-species heart transplants, or cardiac xenotransplantation. A pig-to-baboon heart transplant had previously worked for 57 days, though that was just in a single case, per the Guardian. The development further raises the possibility that pig hearts could someday work in humans, perhaps putting an end to donor waiting lists, though much research is needed before that could happen.
One hurdle scientists would have to overcome: ensuring that pig hearts didn't transmit pig viruses into humans, explains Nature in a separate article on the development. In the study, the scientists used pig hearts genetically modified to be more like baboon hearts (and thus, human hearts, too). They experimented with different methods of preserving the hearts and preparing them for transplant, and found success in the last group of five. One baboon had to be euthanized almost immediately, but the other four survived in good health through the experiment's three-month duration. At that point, two were euthanized, but scientists extended the experiment for the others. One lived 182 days and the other 195 before they, too, were euthanized, which Scientific American explains was "an action required under the study protocol." (Also this week: the first birth after a uterus transplant from a deceased donor.)