US doctors have reported the longest-functioning pig-to-human kidney transplant on record, with the organ working inside patient Tim Andrews for 271 days before it was removed. The team at Mass General Brigham hospital say the case demonstrates that xenotransplantation — using organs from other species — could act as a "bridge" for patients awaiting a human donor, offering hope amid severe shortages of transplantable organs. Andrews, who had end-stage kidney disease caused by type 2 diabetes, said the procedure spared him months of dialysis and gave him "hope" at a time when the wait for a human kidney could have taken years longer than he was expected to survive on dialysis alone.

Andrews received the transplant, sourced from a genetically modified Yucatan miniature pig with 69 genomic changes designed to "humanise" its organs, in January 2025 at the age of 66. The kidney functioned immediately and continued working for 271 days until blood vessel damage caused it to fail around six months in, prompting its removal in October 2025; Andrews then needed 82 days of dialysis before receiving a human donor kidney in January 2026, which has since worked well. Doctors highlighted the scale of demand driving this research, noting around 100,000 people are on the kidney waiting list in the US and over 7,000 in the UK, with far fewer transplants available each year than needed.