**1. Introduction**

Orthotopic liver transplantation (OLT) was initially developed in the 1960s as treatment for individuals dying of end-stage liver disease. It began to be utilized in the 1980s as salvage therapy in the setting of acute liver failure (ALF). Prior to the use of OLT, ALF mortality rates reached 80-85%, and the early post-transplant survival rates were much lower than those following transplantation for chronic liver diseases (Bernuau et al., 1986a). Over the past thirty years, however, with advances in critical care management and in the field of liver transplantation, 1-year survival rates following OLT for ALF have improved to 60-80% (Bismuth et al., 1995; DeVictor et al., 1992; Hoofnagle et al., 1995; W Lee, 2003; O'Grady et al., 1988). ALF is one of the few conditions for which a patient can be listed as a United Network for Organ Sharing (UNOS) status 1A (urgent) patient in the United States and "super urgent" in the United Kingdom. Although about half of ALF patients undergo OLT, ALF accounts for less than 10% of US transplants and approximately 11% in Europe (Freeman et al., 2008).
