A team of surgeons have successfully transplanted a genetically modified pig kidney into a living patient for the first time, a US hospital said Thursday.

The four-hour operation was carried out on Saturday on a 62-year-old man suffering from end-stage kidney disease, Massachusetts General Hospital (MGH) said.

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

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

"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 team which carried out the operation.

The hospital said the pig kidney used for the transplant had been genetically-edited to remove harmful pig genes and add certain human genes.

The hospital said the patient, Richard Slayman of Weymouth, Massachusetts, "is recovering well at MGH and is expected to be discharged soon."

Slayman, who suffers from Type 2 diabetes and hypertension, had received a transplant of a human kidney in 2018 but it began to fail five years later and he has been on dialysis.

Slayman said he agreed to the pig kidney transplant as "not only as a way to help me, but a way to provide hope for the thousands of people who need a transplant to survive."

Slayman is Black and the hospital said the procedure could be of particular benefit to ethnic minorities who suffer from high rates of kidney disease.

"This health disparity has been the target of many national policy initiatives for over 30 years, with only limited success," said Slayman's nephrologist, Dr Winfred Williams.

"An abundant supply of organs resulting from this technological advance may go far to finally achieve health equity and offer the best solution to kidney failure -- a well-functioning kidney -- to all patients in need," Williams said.

The transplantation of organs from one species to another is a growing field known as xenotransplantation.

Pig kidneys had been transplanted previously into brain dead patients but Slayman is the first living person to receive one.

Pig hearts were transplanted recently into two patients in the United States but both survived less than two months.