The technique consists of perfusing organs so that their metabolic functions are active.
The limited number of organs is also due to the fact that clinical practice consists of storing them for no more than 12 hours on ice. Photo: Shutterstock.
The progress of the Zurich University Hospital opens a window to increase the number of transplantable organs and reduce waiting lists. he gets it thanks to giving second chances to organs that would be rejected in normal procedures.
And transplant of liver requires that the organ not spend more than twelve hours outside the body, an obstacle that might end thanks to a new technology that allows it to be preserved for at least three days, as has been shown with a patient who is still healthy a year following receiving the organ.
This technique still requires more trials before thinking regarding its common use, but it opens a window to “increase the number of transplantable organs, as well as reduce waiting lists and, above all, save many lives”, explains one of the signatories of the investigation, Lucía Bautista Borrego.
The difference between the demand for transplants of liver and the availability of these. The limited number of organs, moreover, This is because clinical practice is to store them for no more than 12 hours on ice.
The team headed by Pierre-Alain Clavien, from the Zurich University Hospital, managed to preserve the liver outside the body thanks to a machine that performs a technique known as ex situ normometric perfusion. The results can be read in Nature Biotechnology.
A technique to save lives
The technique consists of introducing a liquid inside organs (perfundir) within a range of physiological temperatures (34 to 37 °C). This means that their metabolic functions are active, and not “at rest”, as occurs with hypothermic perfusion (at low temperatures), explains Lucía Bautista. For this, the team uses human blood from a blood bank, which “makes perfusion more like it occurs in vivo”.
What makes the team’s technique “special” is the use of a machine developed with engineers from the Federal Polytechnic School of Zurich (ETH), which allows monitoring and control of numerous functionality parameters. “With this we have managed to keep the livers in good condition for several days,” says Bautista.
Once transplanted, in May 2021, the liver functioned normally, with “minimal injury” by returning flow to the internal blood vessels, the authors write.
The patient she only required a basic immunosuppressive regimen for the first six weeks and “rapidly regained quality of life, no sign of damage hepaticsuch as rejection or injury to the bile ducts, which remain healthy one year following the operation”, adds the study.
A second life for organs
The recipient of the organ was a 62-year-old man who suffered from advanced cirrhosis, severe portal hypertension, and multiple and recurrent hepatocellular carcinoma (HCC), who was informed of the technique to which the organ was to be subjected.
The liver was not valid for transplant in a usual procedure and was rejected by other centers, since it came from a patient with sepsis and had a tumor that at the time was not known to be benign, which was later determined. That patient had been subjected, in turn, to a transplant multiple of liverbazo and intestine.
“If we had not used it, the liver It would have ended up in the trash. That is, in effect, the purpose of our project: being able to use organs that can be evaluated and even reconstituted for transplantation, reducing waiting lists and saving lives”, he points.
Keep the liver out of the body gave the option to evaluate and treat it. One of the “obvious advantages” of ex situ perfusion lies in the fact that drugs can be used at higher doses, as they do not produce secondary effects in other organs, for example “in cases of various infections, which was the case in this case”.
Multitude of therapeutic options for specific pathologies
Bautista emphasizes that the therapeutic options “are endless, each specific pathology, in theory, might be treated ex situ with a specialized treatment for each perfused organ”.
In this first transplant, the liver was kept outside the body for three days, because “the patient needed it and received it as soon” as its functionality was restored, but in laboratory tests the team has been able to perfundir organs up to twelve days.
The Spanish researcher adds that any organ that is perfused for several hours is likely to be able to do so for longer periods, such as the heart, kidney or lung. This technique must be adapted to the needs of each organ.which “can be redeemed for the transplant”.
For this technology to be fully integrated into clinical practice, “clinical trials that demonstrate its safety using non-discarded organs, those that can be transplanted,” are necessary. This requires “a few years to be possible, but we are working on it”, he concludes.
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