Boston, Massachusetts - A pig kidney has been successfully transplanted into a living human for the first time, a Massachusetts hospital announced on Thursday.

Massachusetts General Hospital said the genetically-edited pig kidney was transplanted into a 62-year-old man living with end-stage kidney disease.

Surgeons from the Mass General Transplant Center conducted the four-hour-long surgery on Saturday.

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

Mass General Brigham chief executive Anne Klibanski said researchers and clinicians were pushing the boundaries of science to transform medicine.

"Nearly seven decades after the first successful kidney transplant, our clinicians have once again demonstrated our commitment to provide innovative treatments and help ease the burden of disease for our patients and others around the world."

The operation was a milestone in xenotransplantation – the transplantation of organs or tissues from one species to another – as a potential solution to the worldwide organ shortage, the hospital said.

The pig kidney came from a pig that was genetically-edited to remove harmful pig genes and add certain human genes to improve its compatibility with humans. Scientists also inactivated porcine endogenous retroviruses in the pig donor to eliminate any risk of infection in humans.

The patient was recovering well and was expected to be discharged shortly, the hospital said.