The transplant operation took four hours and was carried out on Saturday on a 62-year-old man suffering from end-stage kidney disease, Massachusetts General Hospital (MGH) announced on Thursday.

The hospital said the pig kidney used for the transplant had been genetically edited to remove harmful pig genes and add certain human ones. The hospital also said the patient, Richard Slayman of Weymouth, Massachusetts, "is recovering well at MGH and is expected to be discharged soon."

"The procedure marks a major milestone in the quest to provide more readily available organs to patients," MGH said in a statement.

Transplanting organs from one species to another is a growing field known as xenotransplantation.

A hope for patients in need?

Slayman stated that he agreed to receive a pig kidney transplant knowing that — if successful — it could help him while also providing hope for the thousands of people who need a transplant to survive.

Organ shortages are a chronic problem around the world, and the Boston-based hospital said there are more than 1,400 patients on the waiting list for a kidney transplant at MGH alone.

For the team that conducted the operation, it serves as a hope for millions of patients in need of organs to live.

"Our hope is that this transplant approach will offer a lifeline to millions of patients worldwide who are suffering from kidney failure," said Dr. Tatsuo Kawai, a member of the operating team.

MGH said the pigs used to supply organs were "grown in isolation under special conditions to prevent the pig from being exposed to infections that might harm the human recipient."

"These special pigs have organs of similar size and function to human organs," it added. "The genetic modifications of these pigs have also made them more compatible with humans."

Pig kidneys had been transplanted previously into brain-dead patients, but Slayman is the first living person to receive one. Two men received genetically modified pig heart transplants, but neither man lived more than two months after the operations.

According to the United Network for Organ Sharing, more than 100,000 people in the US await an organ for transplant, with kidneys in the greatest demand. Thousands of people die every year while waiting for organs to become available.

ssa/sms (Reuters, AFP)