Xenotransplantation has long been a dream of transplant surgeons, who are faced with a critical shortage of suitable organs. In the 1960s, researchers began testing chimpanzee and baboon organs in humans with limited success, but raising enough animals for transplants would be impractical.
Pigs could provide a more reasonable source of organs, because they are closer to humans in size and anatomy, and are already produced in mass quantities for agriculture. Pig organs might even have some advantages over human equivalents. Surgeries could be scheduled in advance and organs used fresh, rather than requiring that a patient and a surgical team be available at a moment’s notice when a genetically compatible donor dies.
The FDA recommends that, to minimize public-health risks, pig organs be transplanted only into people who have no other option and whose quality of life would be significantly improved by the operation. The agency says it has policies for long-term patient monitoring and for prohibiting people with pig organs from donating blood because of the risk of disease transmission.