The sudden demise of engineer Rick Slaight before kidney transplantation, as per his family and Massachusetts General Hospital's statement.
Hospital declined to disclose the cause and timing of Slaight's death citing privacy concerns.
Slaight, who suffered from diabetes and high blood pressure, was on dialysis for years due to kidney failure.
Slaight received a human kidney donation in 2018, which ultimately failed..
He underwent a pig kidney transplantation in March, marking a milestone in xenotransplantation research.
Recent efforts included modifying pig organs for potential human transplantation.
Teams from Langone Health and the University of Alabama successfully transplanted pig kidneys into brain-dead individuals, extending their survival for two months.
Previous attempts involved pig heart transplants into two men, resulting in their deaths within two months.
His family stated that his legacy would continue to inspire patients, researchers, and healthcare professionals worldwide.
They appreciated the leadership in xenotransplantation and the lasting memories created during their time with Rick.