A kidney transplanted from a pig has functioned inside a patient for 271 days, marking the longest duration on record, according to doctors at Mass General Brigham hospital in the United States. Tim Andrews, the patient, expressed that the transplant provided him with "hope" and alleviated the need for months of hospital visits for dialysis.
Context
The team at Mass General Brigham suggests that pig organs could serve as a temporary solution until a human transplant becomes available. Despite the success of the pig kidney, it ultimately failed and was removed, necessitating a brief period of dialysis for Andrews until a human donor was found.
In the U.S., approximately 100,000 individuals are on the waiting list for a kidney, while only 25,000 transplants occur annually. In the UK, over 7,000 people are awaiting kidney transplants, with some facing a wait of up to seven years.
Developments
Andrews, who was diagnosed with end-stage kidney disease due to type 2 diabetes, underwent the xenotransplant on January 25, 2025. The genetically modified pig kidney was successfully attached to his blood vessels, allowing it to filter blood immediately. However, after 271 days, the kidney was removed in October 2025 due to complications, and Andrews required 82 days of dialysis until receiving a human organ in January 2026.
