Doctors at the Massachusetts General Hospital in Boston, U.S., transplanted a pig’s kidney into a 62-year-old patient in a groundbreaking medical breakthrough that has recorded zero complications so far.

Urine started to flow from Richard Slayman’s new kidney, which came from a genetically altered pig, not long after his surgery on March 16, medical professionals said. 

The kidney is an integral body organ that filters waste from the blood and, by extension, the body.

For decades, medical experts have proposed xenotransplantation, the implantation of animal organs, cells and tissues into a human being, as an alternative to replacing damaged organs of ailing patients.

However, the issue of incompatibility stood as a barrier since the human immune systems rejected the foreign organs, preventing them from functioning in the expected capacity.

Doctors at Mass Gen found a way to circumvent the barrier by modifying the animals to make their organs more receptive to the human body. In this instance, the pig was modified by eGenesis, a biotechnology company that specialises in researching human-compatible organs.

The genes most likely to be rejected by the human body were removed from the pig and replaced with seven human genes to boost the pig’s compatibility with the receiving human body. It worked.

Mr Slayman, doctors said, was recuperating just fine and had begun to walk in the medical facility since his transplant surgery on Saturday.

Mr Slayman, 62, had suffered from diabetes and hypertension and had even received a kidney transplant in 2018. However, it did not take long for the kidney to fail within five years of the transplant, which compounded his ailing condition.

The patient’s case worsened in 2023 when he continued his dialysis treatment and was often hospitalised.

He was initially sceptical when offered the option of a pig kidney transplant but later went with it.

“I saw it not only as a way to help me, but a way to provide hope for thousands of people who need a transplant to survive,” The New York Times cited Mr Slayman as saying.

Leonardo V. Riella, the medical director for kidney transplantation at Mass General Hospital, said dialysis may soon “become obsolete” if Mr Slayman’s procedure can be replicated on a large scale.