Pig kidney works for a record 271 days inside the body of surviving American

An American lived for a record 271 days with a transplanted pig kidney before Boston doctors replaced it with a human kidney earlier this year — a transplant that has kept him alive ever since, researchers said Thursday. This patient’s treatment at Mass General Brigham marked a significant step forward in xenotransplantation, the transplantation of living organs from one species into another, according to findings published in The Lancet medical journal. The case shows that a transplanted pig kidney can safely support renal function “while also serving as a bridge” to a subsequent transplant with a human kidney, the study authors wrote. Tim Andrews was 66 when he received the pig kidney. Over the following 271 days he needed no dialysis before receiving a human transplant, according to a statement from Mass General. “His case represents the longest dialysis-free survival following porcine kidney xenotransplantation in a living human and the first transition to human kidney transplantation,” the hospital said. Xenotransplantation could soon become a game-change, life-saving option, according to the study’s lead author Dr. Leonardo Riella. “The organ shortage is the greatest crisis we have right now in transplantation,” wrote Riella. “We know that the best treatment option for patients with end-stage kidney disease who have developed renal failure is transplantation, but we simply don’t have enough human organs to transplant in a timely manner.” More than 100,000 people are on the national transplant waiting list. The vast majority are waiting for a kidney. For patients like Andrews, using pig kidneys could help buy them enough time to find a human donor. “Our vision is that xenotransplantation could help address this gap — initially as a bridge to get patients off dialysis while they wait for a human donor kidney, and potentially, as we establish long-term safety and durability, as a destination therapy in its own right,” Riella said. Mass General performed the world’s first pig-to-human kidney transplant in 2024; that patient lived for 52 days before dying of cardiac causes unrelated to the transplant, the hospital said.