Extracorporeal whole liver perfusion for acute liver failure

Evidence-based recommendations on extracorporeal whole liver perfusion for acute liver failure. This involves blood being diverted from a large vein, usually in the leg, to a whole liver (perfusion) outside the body (extracorporeal) and returned to the patient through another large vein, usually in the neck.

# Recommendations
Evidence on the safety of extracorporeal whole liver perfusion for acute liver failure shows serious, well-recognised complications. Evidence on efficacy is inadequate in quantity and quality. Therefore, this procedure should only be used in the context of research. Find out what only in research means on the NICE interventional procedures guidance page.
Clinicians and centres doing this procedure must follow the relevant regulatory and legal requirements of the Human Tissue Authority and the procedure should only be done in accordance with the policies of the NHS Blood and Transplant (NHSBT) Organ Donation and Transplantation Liver Advisory Group. Details of any patient who has a liver transplant after extracorporeal whole liver perfusion for acute liver failure should be entered into the NHSBT UK transplant registry, and clinical outcomes should be reviewed locally.
Further research should report details of patient selection, the exact protocol followed, the type of liver used, and long-term immunological and microbiological surveillance. Outcomes should be reported in a way that allows the procedure to be compared with other current treatments.
The procedure should only be done in centres specialising in treating acute liver failure and liver transplantation by a multidisciplinary team experienced in managing this condition.# The condition, current treatments and procedure

# The condition
Acute liver failure is characterised by a rapid (typically in less than 4 weeks) decline in liver function. Causes include poisoning because of alcohol, pharmaceutical or recreational drugs, and viral infection. Less common causes are metabolic disease and acute fatty liver of pregnancy.

# Current treatments
Untreated, acute liver failure can have a high mortality. Current treatment options include medication (to reverse poisoning and to prevent complications caused by acute liver failure), temporary liver support therapies (such as haemodialysis or filtration, plasma exchange, and bioartificial liver support), hepatocyte transplantation and liver transplantation.

# The procedure
In this procedure a veno-venous circuit is usually used to perfuse the patient's blood through an extracorporeal whole liver. The aim is to provide metabolic support and prolong survival, to allow time for the patient's liver function to recover or to find a suitable donor liver for transplantation.
Blood is pumped from a catheter inserted into the femoral vein through an oxygenator and the hepatic artery and portal vein of an extracorporeal whole liver. The liver may be a human liver not suitable for transplantation or a xenogeneic liver (typically a pig liver). Effluent blood from the extracorporeal liver, which is maintained at a normal temperature with a normal pH and electrolytes, is returned to the patient through a subclavian or jugular venous cannula. The literature describes modifications to the technique, such as isolating the patient's immune system from the extracorporeal liver and using different sites for venous access.
Extracorporeal perfusion is continued for up to 5 days until either the patient has a liver transplant or their liver function recovers.