A critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver. Based on this hypothesis, albumin dialysis is used to remove those substances. Albumin dialysis with recirculation (MARS) is the most used system but required specific system and expert environment. Alternative system without recirculation (SPAD) is less expensive and can be realised in critical care services trained to extrarenal epuration. The primary objective of this study is to compare biological and clinical efficacy, pulsatility index of middle cerebral artery modification and tolerance of both systems.