By Luisa Stöckli, Ambassador - Swtizerland
What if we could grow fully functioning organs for those in need? What if we could store them for when the time is right? What if we could save our patients from dying too early just because when their organs are giving up, we do not have the missing pieces ready?
In Switzerland, 425 people were listed for urgently requiring a liver donation, however, only 135 organs were transplanted during the year 2020 (1). This gap between supply and demand exists since the beginning of transplantation medicine. Some countries pass laws trying to increase available organs, while others believe in information and prevention campaigns. Donor organs are a precious commodity, and it is of utmost importance to use the few available in the most efficient manner possible.
One example that illustrates this principle of maximizing the output of one organ is a world premiere performed at the University Hospital Zurich in 2010. The team decided to split a big donor lung into four segments, and with two segments transplanted per person saved the lives of not only one but two teenagers suffering from cystic fibrosis, an inherited disorder leading to progressive lung damage (2).
Almost ten years later, another breakthrough in transplantation medicine was achieved in Zurich. Until then, donor livers could not be stored for longer than a few hours outside the human body.
This time frame allowed for the organ being checked for sufficient quality for transplantation but did not leave enough time to treat those livers at the brink of being rejected for donation to make them transplantable.
A multidisciplinary team of researchers from the University Hospital of Zurich, ETH Zurich and the University of Zurich under the umbrella of Wyss Zurich institute has developed a machine that mimics the human body in such a precise manner, that it was made possible to keep a donor liver alive inside for seven days.
The machine consists of a pump that imitates the heart and perfuses the donor liver, and an oxygenator serves as replacement for the lungs. The liver is moved in the rhythm of the oxygenation as it would be in the living human body due to the diaphragm. In addition, hormones and nutrients are infused and a dialysis replaces the kidneys.
In this setup, the additional time gained is not only a comfort for the patient and the doctors to thoroughly plan the surgery, but most importantly. it is possible to treat injured cadaveric livers to make them suitable for transplantation. Not only for those scenarios the liver tissues’ great potential to regenerate comes in handy.
The abilities of this new machine paired with the fast regeneration of liver tissue are paving the way for maybe someday be able to share a donor liver among multiple patients on the waiting list by dividing it into pieces and letting them grow back to full size in this machine before transplantation.
Furthermore, a wider range of therapies following the same principles becomes available for patients who do not have the opportunity to benefit from a liver graft. Until this day, many liver cancers are inoperable because too much tissue would need to be removed, however, if this machine could be implemented into daily routine, those surgeries could be given green light (3,4).
All in all, this novel technology can help alleviate donor organ shortage and save the lives of hundreds of people.
The first study of the “Liver4Life” project was published in “Nature Biotechnology” in January 2020 and showed that six out of ten poor-quality livers that were perfused in the innovative machine made a full recovery within seven days. Reference: Eshmuminov D, Becker D, Bautista Borrego L, Hefti M, Schuler MJ, Hagedorn C, Muller X, Mueller M, Onder C, Graf R, Weber A, Dutkowski P, von Rohr PR, Clavien PA: An integrated perfusion machine preserves injured human livers for one week, Nature Biotechnology, January 2020, doi: 10.1038/s41587-019-0374-x
About the author
(1) Swisstransplant. Preliminary statistics 2020.
(2) Frey, Arabelle. Eine Spenderlunge reicht für zwei Empfänger. SRF Puls: Körper und Geist, 16.05.2011.
(3) Liver4Life. Regeneration of the human liver outside the body. Wyss Zurich. https://www.wysszurich.uzh.ch/projects/wyss-zurich-projects/liver4life
(4) Eshmuminov D, Becker D, Bautista Borrego L, Hefti M, Schuler MJ, Hagedorn C, Muller X, Mueller M, Onder C, Graf R, Weber A, Dutkowski P, von Rohr PR, Clavien PA: An integrated perfusion machine preserves injured human livers for one week, Nature Biotechnology, January 2020, doi: 10.1038/s41587-019-0374-x