Research develops new machine to repair damaged liver

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Organ transplantation has always been a major problem in the medical field. Due to the limited number of donated organs, a large number of patients need to wait in long queues for life-saving organs. In the United States alone, more than 100,000 people are waiting for a suitable organ, and more than 90,000 of them are waiting for a liver transplant. The average waiting time for a liver is three to five years, which means that, on average, more than 20 people die every day while waiting for an organ.

However, even after waiting for a matching donated liver, it can only be stored for 12 hours in traditional cold storage. During this time frame, physicians need to evaluate, transport, and implant donor grafts for human transplantation. Not only does this greatly limit the organ's viability until it reaches the recipient, it also largely rules out the possibility of repairing the organ before transplantation. Damaged organs are often discarded, further compounding the problem of organ shortages.

To solve this problem, researchers from Switzerland have developed a new machine that can not only prolong the preservation time of the liver by means of extracorporeal circulation, but also repair the damaged liver. Known as a perfusion machine, the machine has a pump in place of the heart, an oxygenator in place of the lungs, and a dialysis device in place of the kidneys, creating pulsatile blood flow in the hepatic artery, creating a pulse waveform that mimics the environment in the body.

In addition, the machine can inject nutrients and hormones into organs, and even act like a diaphragm to move the liver to the rhythm of human breathing. Specifically, to avoid over-oxygenation of the portal vein, it can mix deoxygenated venous blood in the reservoir with fresh oxygenated blood in the oxygenator. Oxygen saturation is automatically adjusted by an algorithm to maintain the target saturation of the vena cava at 65% diaphragm.

In the experiment, the researchers used 10 damaged livers, which were of poor quality and could no longer be transplanted. But under the repair of the perfusion machine, six of the livers met the criteria for "good" donor organs. With the patient's consent, one was successfully transplanted into the organ recipient. After follow-up investigation, the patient quickly returned to normal life without any signs of liver damage.

Overall, the new machine that mimics human functions opens up new horizons for clinical research and is expected to extend the time window for assessing the feasibility of donating organs to 10 days. Looking ahead, the researchers plan to conduct further experiments to create a more powerful perfusion machine.