Landmark Surgery: Pig Lung Survives Nine Days in Human Recipient

China Reports First Attempted Pig-to-Human Lung Transplant
In a landmark step for transplantation medicine, surgeons in Guangzhou, China, have reported the world’s first attempt to transplant a genetically modified pig lung into a human. The procedure, carried out on a brain-dead male recipient, marks an extraordinary development in xenotransplantation, a field that aims to overcome the chronic shortage of human donor organs by turning to animal sources.

The Groundbreaking Procedure
The recipient was a 39-year-old man who had been declared brain-dead following a severe intracranial hemorrhage. With consent from his family, a medical team at the First Affiliated Hospital of Guangzhou Medical University performed the experimental surgery, not as a curative measure but to observe how a pig lung would function in the human body.

The donor lung came from a pig specifically engineered with multiple genetic edits. Scientists deleted several porcine genes known to trigger strong immune responses in humans while adding human genes to help reduce the likelihood of organ rejection. This hybrid organ represented the latest in a series of gene-editing strategies aimed at making animal organs more compatible with the human immune system.

During surgery, the man’s right lung was left in place to support ventilation while the pig lung was transplanted into the left side of the chest. A comprehensive regimen of immunosuppressive drugs was administered, including agents commonly used in advanced transplant medicine, to maximize the chances of acceptance.

Nine Days of Survival
Post-surgery monitoring lasted nine days—an unusually long window in the field of lung xenotransplantation. The transplanted organ functioned throughout this period, enabling gas exchange and supporting oxygenation without signs of immediate catastrophic failure.

Crucially, the team observed no evidence of hyperacute rejection, a common problem in xenotransplantation where the recipient’s immune system attacks the organ within hours. Instead, the lung displayed function consistent with a viable graft.

Complications did emerge. Within the first 24 hours, the lung developed edema typical of ischemia-reperfusion injury, a well-known risk in transplantation. By the third postoperative day, antibody-mediated rejection was noted, and by day six, the damage became more pronounced. Interestingly, signs of partial recovery were recorded by the ninth day. At the request of the family, the experiment was ended after this monitoring period.

Why Lungs Are the Final Frontier
The achievement is notable because lungs are widely considered the most difficult organ to transplant across species. Unlike kidneys or hearts, lungs are directly exposed to the outside environment through the air we breathe. This makes them uniquely vulnerable to pathogens, allergens, and pollutants, all of which stimulate multiple layers of immune defense.

The lung’s fragile alveolar-capillary membrane, designed for rapid gas exchange, is highly sensitive to inflammation and swelling. Even small disruptions in this delicate structure can render the organ nonfunctional.

Additionally, lungs carry an abundance of immune cells ready to mount a defense. When combined with the stress of reperfusion, this immune landscape frequently triggers powerful inflammatory cascades, leading to early graft dysfunction. For these reasons, lungs have long been regarded as the “last frontier” of xenotransplantation.

Genetic Engineering Meets Immunology
The success of the Chinese team in sustaining the pig lung for over a week was achieved through a dual strategy of genetic engineering and pharmacological immunosuppression. The donor pig carried six modifications: the deletion of pig genes that produce antigens strongly recognized by humans, and the insertion of human genes designed to blunt immune rejection.

On the recipient’s side, a cocktail of immunosuppressive drugs was used, including therapies targeting T cells, B cells, complement activation, and inflammatory signaling. This aggressive regimen appeared effective at suppressing early rejection, though antibody-mediated damage still developed as the days progressed.

Experts emphasize that the procedure demonstrates feasibility rather than readiness for clinical application. The presence of rejection and edema underscores the immense complexity of lung xenotransplantation and the need for further refinement.

Ethical Considerations
As with earlier pig-to-human kidney and heart transplant attempts, the Chinese procedure was conducted in a brain-dead patient rather than a living volunteer. This approach balances scientific exploration with ethical responsibility by avoiding undue harm to a conscious patient while still generating crucial data.

The choice highlights the central dilemma in xenotransplantation: how to progress toward life-saving clinical use while ensuring safety and respecting ethical boundaries. Advocates argue that such experiments are essential, given the dire shortage of donor lungs and the thousands of patients who die each year waiting for transplants. Critics caution that more transparency and oversight are needed before moving toward living recipients.

Implications for the Future
Although far from clinical deployment, this operation represents a major step toward a new era in transplantation medicine. If pig lungs can be made safe and durable in humans, it could revolutionize the management of end-stage respiratory disease.

Chronic obstructive pulmonary disease, pulmonary fibrosis, and advanced emphysema account for a large proportion of lung transplant demand. Donor shortages remain severe, with only a fraction of candidates receiving timely transplants. Xenotransplantation could potentially alleviate this bottleneck.

Still, major challenges remain. Preventing antibody-mediated rejection, controlling reperfusion injury, and ensuring long-term graft survival will require more advanced genetic engineering and possibly new immunotherapies. Additionally, questions of zoonotic infection and viral transmission from pigs to humans continue to be investigated.

The Global Race in Xenotransplantation
China’s announcement adds momentum to an already competitive global race. In the United States, researchers have transplanted genetically modified pig kidneys and hearts into both brain-dead and living recipients. Europe has been advancing preclinical models, and companies worldwide are investing in xenotransplantation biotechnology.

The Guangzhou case illustrates both the promise and peril of this field. It shows that pig lungs can function inside the human body for a period long enough to allow scientific observation and suggests that many long-feared hurdles, such as hyperacute rejection, may be surmountable. At the same time, the persistent signs of rejection remind clinicians that clinical translation is still distant.

Lessons for Physicians
For the medical community, this breakthrough is a call to prepare for the eventual integration of xenotransplantation into clinical practice. Physicians must be aware of the science, the ethical frameworks, and the potential risks.

Pulmonologists and transplant surgeons will need to understand new immunosuppressive regimens, while infectious disease specialists will be vital in monitoring for cross-species infections. Ethicists and policymakers must address public concerns, including animal welfare and biosecurity.

As the field progresses, interdisciplinary collaboration will be essential. The pig-to-human lung transplant in China is not a final answer but the opening chapter of what could become one of the most transformative medical revolutions of our time.