The first living patient to receive a genetically modified pig kidney transplant has died, the US hospital that carried out the procedure said.

"Mass General is deeply saddened at the sudden passing of Mr. Rick Slayman. We have no indication that it was the result of his recent transplant," the Boston hospital said in a statement issued late Saturday.

In a world first, surgeons at Massachusetts General Hospital transplanted the genetically edited pig kidney into a 62-year-old man who was suffering from end-stage kidney disease.

They successfully carried out the four-hour operation in March.

"Slayman will forever be seen as a beacon of hope to countless transplant patients worldwide and we are deeply grateful for his trust and willingness to advance the field of xenotransplantation," the hospital statement said.

Organ shortages are a chronic problem around the world and the Boston hospital said in March that there were more than 1,400 patients on its waiting list for a kidney transplant.

The pig kidney used for the transplant was provided by a Massachusetts biotech company called eGenesis and had been modified to remove harmful pig genes and add certain human genes, according to the hospital.

Slayman, who suffered from Type 2 diabetes and hypertension, had received a transplanted human kidney in 2018, but it began to fail five years later.