Artificial Liver System Shows Promise

A new artificial liver system, called albumin dialysis, uses special filters and proteins to remove toxic substances from the blood while sparing helpful compounds. In a phase I trial, six of 20 seriously ill patients went on to receive a transplant, three of whom are still alive. Two other patients recovered liver function without needing a transplant. Data on the trial were published in the August 2002 issue of Surgery.

The new system seeks to avoid the limitations of bioartificial livers and filtering devices. Albumin dialysis pumps the blood out of the body and into a plastic tube filled with hollow fibers made of a membrane coated with albumin. On one side of the fiber's membrane is the blood, and on the other, a dialysis solution containing more albumin. The toxins in the blood are attracted to the albumin on the membrane, which is stickier. The albumin on the membrane passes the toxins along to the albumin in the solution as it flows by. The smaller toxins flow through the membrane's tiny pores into the dialysis solution, while the patient's own albumin, too large to fit through those pores, returns to the body with the blood.

The system, called MARS (molecular adsorbent recirculating system) was invented in Germany and the equipment is made by Teraklin AG (Rostock, Germany). The trial was conducted by researchers at the University of Michigan (U-M, Ann Arbor, USA). They are preparing to participate in a multicenter, randomized trial comparing albumin analysis with standard medical treatment in chronic liver failure patients who are in hepatic comas. The new trial will begin in early 2003.

"We must also explore whether the system can help patients regain function in their own livers, as two of our patients did,” said Robert Bartlett, M.D., U-M professor of surgery and lead investigator. "Currently, we are using albumin dialysis only for patients in the intensive care unit who need emergency liver transplants, but we will soon extend the treatment to other patients with liver disease.”




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