An American man named Tim Andrews lived for 271 days with a kidney transplanted from a pig before Boston doctors replaced it with a human kidney earlier this year. According to researchers, this transplant has kept him alive ever since. The treatment at Mass General Brigham represents a major advancement in the field of xenotransplantation, which involves transplanting organs from one species to another. Findings from this case were published in The Lancet, a respected medical journal. The study highlights that a pig kidney can safely support kidney function in a human and can act as a temporary solution while a human donor kidney is being sought. Tim Andrews was 66 years old when he received the pig kidney. During the 271 days he lived with the transplanted organ, he did not need dialysis — a treatment used to filter waste from the blood when the kidneys fail — before receiving the human kidney. This case marks the longest period of dialysis-free survival following a pig kidney transplant in a living human, and it is the first known instance of a successful transition from a pig kidney to a human kidney transplant, according to the hospital. Researchers believe this could be a significant step toward addressing the critical shortage of human organs for transplantation. Xenotransplantation, the practice of using animal organs in human patients, could become a life-saving solution for the growing number of people waiting for organ transplants. Dr. Leonardo Riella, the lead author of the study, noted that the shortage of human organs is the greatest challenge in transplantation today. Over 100,000 people are currently on the national transplant waiting list in the United States, with the majority needing a kidney. For patients like Andrews, pig kidneys could provide crucial time while they wait for a suitable human donor. Mass General Brigham previously performed the world’s first pig-to-human kidney transplant in 2024. That patient, however, lived for only 52 days before passing away due to cardiac causes unrelated to the transplant, the hospital reported. The success of Andrews’ case provides new hope and valuable insights for the future of xenotransplantation, offering a potential bridge to human donor kidneys for patients in desperate need.