BOSTON, Massachusetts: The first recipient of a genetically modified pig kidney transplant, Richard "Rick" Slayman, has died nearly two months after he underwent the procedure.

His family and the hospital that performed the surgery announced his death over the weekend.

In March, Slayman had the transplant at Massachusetts General Hospital at the age of 62.

They believed the pig kidney would last for at least two years, surgeons initially said.

In a statement, the transplant team at Massachusetts General Hospital said it was deeply saddened by Slayman's passing and offered condolences to his family.

They did not have any indication that he died as a result of the transplant, they added.

Slayman, from Weymouth, Massachusetts, was the first living person to have the procedure.

Two people have previously received heart transplants from pigs, but both died within months.

In a statement, Slayman's family thanked his doctors.

"Their enormous efforts leading the xenotransplant gave our family seven more weeks with Rick, and our memories made during that time will remain in our minds and hearts," the statement said.

"Rick accomplished that goal, and his hope and optimism will endure forever," the statement added.

More than 100,000 people are on the national waiting list for a transplant, most of them being kidney patients, but thousands die every year before they can have their procedures done.