A “bioartificial” liver can save the lives of some patients with the worst kind of liver failure, researchers report.The device won’t be available for medical practices for some time, however, because the money needed to run the trials necessary for government approval isn’t there just now.The device, which uses pig cells to perform the blood-cleansing function of the human liver, was developed by Dr. Achilles A. Demetriou, chairman of surgery at Cedars-Sinai Medical Center in Los Angeles.The study of 171 liver failure patients at 20 medical centers found the device improved the survival rate by 20 percent or more, says a report in the May issue of the Annals of Surgery.