A month ago, the outlook was extremely bleak for 57-year-old Maryland handyman David Bennett—he needed a new heart, but didn't qualify for a donor organ. At least, not from a human. Bennett, who had terminal heart disease, is now part of medical history after the first successful transplant of a pig heart into a human, the BBC reports. Doctors at the University of Maryland Medical Center received emergency authorization from the FDA on New Year's Eve and performed the eight-hour operation Friday. While the long-term outlook is unclear, Bennett is still alive three days later, and the riskiest period for organ rejection has passed, doctors say.
Doctors describe the case as a huge moment for "xenotransplantation"—the transplantation of organs or tissue from animals into humans—which could give fresh hope to thousands of patients on waiting lists. "It’s working and it looks normal. We are thrilled, but we don’t know what tomorrow will bring us. This has never been done before," Dr. Bartley Griffith, who performed the operation, tells the New York Times. He says he discussed the treatment with Bennett in a "pretty strange" conversation in mid-December. The doctor says he wasn't sure Bennett fully understood what he was proposing until he asked, "Well, will I oink?" The patient's son, David Bennett Jr., says his dad received a pig valve around a decade ago. He says when his father told him about the transplant, he initially thought he was confused or delirious.
Dr. Muhammad Mohiuddin says 10 genes were changed to make the transplant from a specially bred 1-year-old pig possible, USA Today reports. Human genes were added and pig genes were turned off to reduce the risk of rejection—and an extra pig gene was turned off to stop the heart growing too big after transplantation. For now, Bennett is hooked up to a heart-lung machine and is being monitored very closely. The Maryland School of Medicine quotes him as saying before the operation: "It was either die or do this transplant. I want to live. I know it’s a shot in the dark, but it’s my last choice." (In October, a pig kidney worked in a human for 54 hours.)