Transplantation: Damaged Lungs Restored With Live Pig's Blood

Researchers at Columbia and Vanderbilt University were able to heal damaged human lungs that were allocated for transplantation by supplying them with live pig’s blood while outside the body.

Pigs

Like many other transplant operations, lung transplantation is not immune to organ shortages. The process is even more delicate because a person’s lungs begin to deteriorate as soon as they die due to lack of oxygen and only remain viable for 6 to 8 hours after death. Eighty percent of the lungs offered for transplantation are unsuitable for transplantation because they are damaged, swollen or filled with fluid.

A discovery made by researchers at Columbia and Vanderbilt University, published in Nature Medicine magazine, could prolong the life of damaged lungs up to 4 days after the death of the donor and keep them viable for transplantation.

Restoration of lung function within 24 hours

For eight years, the research team worked on a system to restore the damaged lungs. By 2017, the research team had already managed to restore the cross circulation of the lungs outside the body, and by 2019 they had managed to regenerate severely damaged pig lungs.

For this new study, the researchers removed six lungs from deceased patients who were not suitable for transplantation. Each lung was placed in a plastic box attached to an artificial respirator. Each lung was then connected to a large vein in the neck of a live pig. Immunosuppressants were then added to the circulatory system composed of the pig and the human lungs.

After 24 hours of cross circulation, the lungs recovered: The lung cells were able to supply oxygen again.

“The results are like science fiction: within 24 hours the lungs seemed to be viable, and laboratory tests confirmed that they had been revived,” write the authors of the study in Nature Medicine.

A technology that needs to be perfected

Although further research is needed before this cross-circulation becomes a clinical reality, these initial results are particularly encouraging and could significantly increase the number of viable lungs for transplantation.

“As a lung transplant surgeon, I have seen that many patients do not receive the lung transplants they desperately need. I find this work fascinating and hope that this technology will make more donor lungs available,” said Zachary Kon, director of the lung transplant program at NYU Langone Health, who did not participate in the study.

The results are all the more optimistic as the procedure does not seem to have any negative impact on the anesthetized pigs. In a previous experiment, the animals were even able to move and feed themselves while being connected to the bloodstream.

The aim is eventually to make this intra-human circulation: A patient would then be able to restore a dysfunctional lung with his own blood supply.