Pig kidney transplant gives man nine‑month break from dialysis

When Tim Andrews was told his kidneys were failing, the usual recommendation was clear: start dialysis and hope for a human donor. Instead, he opted for something that sounded like science‑fiction – a kidney from a genetically modified pig.

On 25 January 2025 surgeons at Massachusetts General Brigham in Boston placed the organ, harvested from a tiny Yucatán pig, into Andrews’ bloodstream. The animal’s DNA had been tweaked – a few sugar molecules that usually trigger a human immune response were stripped away, and seven human genes were added to make the graft more “friendly”.

At first, everything went smoothly. Andrews stopped dialysis, his energy levels rose, and he could enjoy ordinary meals without the harshness of a dialysis schedule. “I felt like I got my life back,” he later told the team, his voice a mix of relief and disbelief.

But the honeymoon didn’t last forever. Six months in, he was hospitalized with a stubborn MRSA infection – the kind of bacteria that scoffs at most antibiotics. To fight it, doctors had to dial down the immunosuppressive drugs that kept his body from rejecting the foreign organ.

Reducing those meds had an unwanted side‑effect: the pig kidney’s tiny blood vessels began to scar. Over weeks, the organ’s function slipped, and by day 271 the graft was no longer viable. The team removed it, and Andrews returned to dialysis for a brief three‑month stint.

In January 2026, a human kidney finally arrived, ending what had become a pioneering, if temporary, solution. The episode marks the first time a pig kidney has acted as a “bridge” to a human transplant, extending the dialysis‑free period far beyond what anyone expected.

“Nine months is mind‑blowing for a xenograft,” says Leonardo Riella, the lead surgeon. “It shows we can buy patients precious time, reduce the wear‑and‑tear of dialysis, and maybe one day replace human kidneys altogether.”

Scientists remain cautious. The cost of such procedures is still unknown, and the need for lifelong immunosuppression carries its own risks. Yet, with roughly 600,000 Americans on dialysis – a treatment that can cost about $100,000 per year per patient – the potential savings are enormous.

Since the first experimental pig kidney transplant in 2024, the Boston team has performed five similar surgeries. Another patient has already eclipsed Andrews’ record, keeping a pig kidney functional for over ten months. Researchers are hopeful, but they stress that widespread adoption is still years away, pending safety data, regulatory approval, and, inevitably, price‑tag considerations.

In parallel, the field is racing on multiple fronts: artificial kidneys, organ regeneration, and better ways to preserve donated organs. All of these could dovetail with xenotransplantation, offering a richer toolbox for a world where kidneys are in perpetual shortage.

For now, Tim Andrews’ story stands as a vivid reminder that the line between science fiction and everyday medicine is moving ever closer.