The transplant, part of a three-person compassionate use study, used a pig kidney with 69 gene edits provided by U

His effort paid off: Tim Andrews, 66, is only the second person known to be living with a pig kidney. Andrews is free from dialysis, Massachusetts General Hospital announced Friday, and recovering so well from the Jan. 25 transplant that he left the hospital a week later.

Another patient has received a transplant with a genetically modified pig kidney. Tim Andrews, a 66-year-old who lives in Concord, N.H., has end-stage kidney disease and had been on dialysis for more than two years to compensate for his failing kidney function.

Surgeons at Massachusetts General Hospital have successfully performed the fourth pig kidney transplant in the U.S. The recipient of the genetically modified pig organ was a 66-year-old man with kidney failure,