Liver Dialysis Appears Effective for Refractory Hepatic Encephalopathy

liver411

Medscape Medical News


Neil Osterweil

Nov. 2, 2002 (Boston) — Patients with episodic type C hepatic encephalopathy who fail to improve despite 24 hours of standard medical therapy may be able to benefit from charcoal-based hemodiabsorption using a liver dialysis unit (LDU), report researchers from Loma Linda University Medical Center in California. Their poster was presented here on Saturday at the 53rd Annual Meeting of the American Association for the Study of Liver Diseases.

In a prospective study of 18 patients with episodic hepatic encephalopathy
(EHE), 16 showed significant improvement in mental status within two days, according to Donald J. Hillebrand, MD, associate professor of medicine, chief of hepatology, and medical director of liver transplantation
at Loma Linda. "Charcoal-based hemodiabsorption utilizing LDU treatments are able to safely, rapidly and effectively resolve EHE failing to respond to 24 hours of appropriate medical management in patients with advanced cirrhosis," write Dr. Hillebrand and colleagues in their study abstract.

Up to one-third of patients with EHE exhibit altered mental status despite
five days of conventional medical therapy, and each episode of encephalopathy in these patients carries a 10% to 30% risk for
mortality, the researchers note. In theory, liver dialysis could improve
symptoms of altered mental status by reducing serum toxins in severely cirrhotic patients.

"Liver dialysis is a completely artificial device that utilizes charcoal to
selectively bind toxins that build up in the setting of liver failure," Dr. Hillebrand told Medscape. "It combines some kidney dialysis-type mechanisms with the liver dialysis?. It uses a membrane to keep the charcoal solution separate from the patient's blood, which improves the compatibility of the machine."

Dr. Hillebrand and colleagues evaluated the efficacy of the treatment in 14
men and 4 women with a mean age of 50 years; the patients all had Child-Pugh class C cirrhosis of the liver, and all had previous episodes of type C hepatic encephalopathy. All but one of the 18 patients were receiving
recurrent or persistent therapy for EHE. The patients had a maximum of three courses of liver dialysis, with each session lasting four to six hours. Therapy was discontinued when patients either showed a predetermined clinical response, went on to transplantation, or had deterioration in their
condition. Mental status was assessed with Conn's criteria (range, 0
[normal] to 4 [coma]).

The treatments appeared to be well tolerated, and mental status improved in the majority of patients. Before treatment, 11 patients had a mental status of grade 2, six had grade 3, and one patient had grade 4. In contrast, posttherapy scores were grade 0 in one patient, grade 1 in 15
patients, grade 2 in one patient, and grade 4 in one patient. There were no significant improvements, however, in measures of liver function or Model for End-Stage Liver Disease (MELD) scores.

Dr. Hillebrand told Medscape that although it's still unclear whether
charcoal-based hemodiabsoprtion using LDU can reduce viral burden in patients with advanced hepatitis C infections, "the most important thing we've learned is that detoxification works?. If you can detoxify these
critically ill cirrhotic patients, you can improve the encephalopathy and
you can improve the organ failure. We're taking what we've learned from this experience and are developing a new and what we think will be a better machine."

Other indications they are considering for treatment with the LDU include
chronic liver failure, hepato-renal syndrome, liver failure after surgical interventions such as cholecystectomy, and liver transplant recipients who receive a marginal graft organ.

But liver dialysis, although promising, still needs to be run through its
paces, according to a physician who was not involved in the study.

"There has not been a lot of experience with it — it's experimental, but
there's been some research over the years into filtering the toxins that the liver normally filters through a dialysis-like mechanism, similar to hemodialysis for kidney failure, but I don't think we're to the point where we
can say that it is usable clinically," said Brian Boyle, MD, attending
physician at the New York Presbyterian Hospital-Weill Cornell Center and assistant professor of medicine in the Department of International Medicine and Infectious Diseases at Cornell University, in an interview with Medscape.

AASLD 53rd Annual Meeting: Abstract 100249. Presented Nov. 2, 2002.

Reviewed by Gary D. Vogin, MD


Neil Osterweil is a freelance writer for Medscape.