In a first, U.S. surgeons transplant pig heart into human patient

Over the years, scientists have turned from primates to pigs, tinkering with their genes.

In a medical first, doctors transplanted a pig heart into a patient in a last-ditch effort to save his life and a Maryland hospital said Monday that he's doing well three days after the highly experimental surgery.

While it’s too soon to know if the operation really will work, it marks a step in the decades-long quest to one day use animal organs for life-saving transplants. Doctors at the University of Maryland Medical Center say the transplant showed that a heart from a genetically modified animal can function in the human body without immediate rejection.

The patient, David Bennett, a 57-year-old Maryland handyman, knew there was no guarantee the experiment would work but he was dying, ineligible for a human heart transplant and had no other option, his son told The Associated Press.