I read an article in the RN Journal about artificial systems that are used to replace the livers functions for patients who are awaiting a live transplant. In 2002 more than 17,000 patients were in need of a liver transplant. Of those 17,000 approximately 5,000 received a transplant. The gap in the amount of receiving and needing patients has been the main driving force behind the efforts to find ways to prolong the lives of awaiting patients. .
The main problem and obstacle of developing a way to replace the functions of liver is duplicating the many important functions the liver is responsible for. Metabolism, filtration, detoxification and synthesis have been the big obstacle in replication of function. These functions are fairly difficult to duplicate artificially. .
On a brighter note there have been many breakthroughs in replicating the livers functions. There have been some support systems developed to mimic some of the functions of the liver. They can be divided into two different categories, artificial and bioartificial. Both types involve the extracorporeal circulation of the patients" blood through filters that remove waste products normally filtered by the liver. Where the two types differ is in the way they achieve the filtering of the wastes in the body. The artificial systems use sorbents, such as charcoal or resins. Bioartificial systems use living hepatocytes. The bioartificial systems also attempt to duplicate other functions of the liver, particularly synthesis.
The earliest types of liver support systems included hemodialysis to remove ammonia and other small molecules from the blood. Newer, nonbiologic liver support systems use sorbents, such as charcoal or albumin, which remove additional toxins by binding to them. The first of this type of this system was the HemoTherapies Liver Dialysis unit. It used a charcoal sorbent that removed the water-soluble toxins and balanced the blood chemistry by adding electrolytes and glucose to the patients" blood.
