Surgeons removed a genetically modified pig kidney from a 67-year-old man last week, nearly nine months after he received the pioneering procedure at Massachusetts General Hospital in Boston, officials said on Monday. The kidney was removed “after a period of decreasing kidney function,” according to a statement from the hospital. The patient, Tim Andrews, lived with the pig kidney for a record-setting 271 days. He was the fourth person in the US to receive a genetically modified pig kidney. The first two patients died shortly after their transplants; the third had her kidney removed after 130 days, when her body rejected the organ. “Tim set a new bar in xenotransplantation,” the Mass General Brigham statement said, referring to the process of transplanting organs from one species into another. Andrews “will now resume dialysis and remain on the list for a human donor kidney,” the hospital added. The nation faces an acute shortage of human organs. More than 100,000 people are on waiting lists to receive an organ transplant; roughly 90,000 of them are awaiting kidneys. The shortage has prompted an effort to genetically modify pigs so that their organs can be safely transplanted into humans. The organ Andrews received came from a pig that had received 69 edits to its genome, including some designed to disable viruses that might pose a risk to people, and others designed to make the organ more compatible with the human body, reducing the odds of immune rejection.

