A genetically engineered pig kidney from a Yucatan miniature pig named Wilma was transplanted into 66-year-old Tim Andrews with end-stage kidney disease as a temporary bridge to a human transplant, marking a world first in using a pig kidney as a bridge.

The pig kidney survived for 271 days, providing nine months of dialysis-free life before failing and being replaced by a human donor kidney, the longest such period reported and the first transition from a pig kidney to a human kidney in the same patient.

Initially successful, the transplant allowed Andrews to resume a normal life, but after about six months he developed a MRSA infection and reduced immunosuppression led to chronic damage in the kidney’s blood vessels, culminating in organ failure and removal of the pig kidney.

The transplantation team notes the procedure is experimental and cost estimates are unavailable, but emphasizes its potential to reduce dialysis-related burden and to bridge long organ wait times.

The case illustrates both the promise and current limitations of xenotransplantation as a clinical approach to address organ shortages.

The nine-month case is part of the expanded access program, a FDA pathway enabling seriously ill patients to access experimental treatments when no good alternatives exist.

Experts describe xenotransplantation as a potential way to address organ shortages, initially as a bridge to a human transplant and potentially as a standalone therapy in the future.

The study’s lead author highlighted that over 100,000 people are on the national transplant waiting list for kidneys, and xenotransplantation could bridge patients to human transplants or eventually become destination therapy.

The medical team positions xenotransplantation as a temporary solution or 'bridge' until a human donor organ becomes available.

The study is a single-case report without a control group, underscoring the need for broader trials to assess safety, durability, and applicability to more patients.

Dialysis is burdensome but life-sustaining, fueling interest in alternatives like xenotransplantation to reduce time on dialysis.

The FDA has authorized a formal trial with up to 33 patients awaiting human kidney transplants, planned for 2027, with ongoing transplants under expanded access in the interim.