There exists no reliable system of artificial liver support, despite a half century of expensive research.
There are kidney machines, heart machines, lung machines; there are well established methods to manage loss of intestines, pancreas, endocrine glands, skin, even reproductive organs.
There is no liver machine, and less radical management of liver failure is reactive. We lack the fundamental understanding of liver function necessary for confident, precise management. We have no medical means to reactivate brain and kidney function in liver failure; only liver recovery or transplant does that.
Livers for transplant are hard to obtain. In liver failure the need is urgent: the patient will die in a few days without the transplant. Perfusion techniques mean a liver taken for transplant can now be kept in reasonable condition for a day or two, buying time to bring liver and patient together, in a prepared theatre, with experienced staff. Even so, the opportunities for transplant in liver failure are few. There is no prospect of a 'liver bank', like a blood bank.
In all surgery the best results are from routine, planned procedures. Liver transplantation is major surgery demanding specialised facilities and meticulous preparation.
Animal livers have not proved useful. They cannot be transplanted. In artificial systems they produce plasma for the animal species of origin, which is likely to have serious differences from human plasma.
Liver failure is an unsolved clinical problem. We may appreciate the magnitude and complexity of the abnormalities in liver failure, but so far there is no full understanding of what happens when the liver goes down. Without that strategic understanding management has to be based on trial and error, experience, even guesswork.
Liver medicine awaits a breakthrough in research into the basic physiology of the liver.