This machine keeps livers alive outside the human body for a week

Injured human livers have reportedly been repaired and kept alive inside a machine for a week, a huge increase on a previous maximum of roughly one day.

Described as a “major breakthrough” by its developers in Zurich, Switzerland, the device could lead to an increase in the number of available organs for transplantation and potentially save the lives of patients with severe liver diseases or cancer.

The machine – developed by researchers at University Hospital Zurich (USZ), ETH Zurich, Wyss Zurich and the University of Zurich – is based on a “complex” system of perfusion, which provides blood to the organ while mimicking the body’s core functions. Injured livers from dead bodies, initially not suitable for transplantation, can reportedly regain full function during perfusion for several days.

The long-term perfusion of poor-quality organs allows for a wide range of medical strategies, according to the researchers, including injury repair, cleaning of fat deposits or even regeneration of partial livers.

“The success of this unique perfusion system – developed over a four-year period by a group of surgeons, biologists and engineers – paves the way for many new applications in transplantation and cancer medicine, helping patients with no liver grafts available,” said Professor Pierre-Alain Clavien, chairman of surgery and transplantation at USZ.

The first study with the device found that six of 10 ‘poor-quality’ human livers recovered to full function within one week of perfusion, despite initially being declined for transplantation ‘by all centres in Europe’. They can now be used for transplantation.

An online announcement included little information of how the machine works, but an unconnected earlier device created by University of Oxford spin-out OrganOx mimicked the human body with flowing blood, a constant temperature of 37ºC and changing pressure to regulate two blood inputs and one output. A Nature study found the Metra device resulted in a 50% lower rate of discarded organs compared to conventional cold storage and halved injuries associated with transplantation. The OrganOx method also resulted in 54% longer preservation times than cold storage, giving an average of 12 hours and up to 24.

The press release does not explain how the Zurich device achieves such a longer preservation time. It is also unclear if the new machine is transportable like the Metra. Professional Engineering has contacted Professor Clavien for more information.

The research was published in Nature Biotechnology.

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