WASHINGTON (AP) — Surgeons have transplanted a pig’s heart into a dying man in a bid to prolong his life.

He’s only the second patient to undergo such an experimental feat.

Maryland doctors said Friday that the man was cracking jokes and able to sit in a chair two days after the transplant.

The doctors at University of Maryland Medicine said 58-year-old Lawrence Faucette was facing near-certain death from heart failure but other health problems meant he wasn’t eligible for a traditional heart transplant.

While the next few weeks will be critical, doctors were thrilled at his early response to the pig organ.