Nevertheless, they are therapies with high complexity that require a complex logistic approach for implementation; a very high cost and possible inducement of important side effects such as immunological issues (porcine endogenous retrovirus transmission), infectious complications and tumor transmigration have been documented. Other biological hepatic systems are Bioartificial Liver Support (BLSS)12 and Radial Flow Bioreactor (RFB).15 Detoxification capacity of these systems is poor and therefore they must be used combined with other systems to mitigate this deficiency. Today its use is limited to centers with high experience in their application. Artificial liver support systems are aimed to temporally replace native liver detoxification functions and they use albumin as scavenger molecule to clear the toxins involved in the physiopathology of the failing liver. Most of the toxins that accumulate in the plasma of patients with liver insufficiency are protein bound, and therefore conventional renal dialysis techniques, such as hemofiltration, hemodialysis or hemodiafiltration are not able to adequately eliminate them. Between the different albumin dialysis modalities, single pass albumin dialysis (SPAD) has shown some positive results at a very high cost; it has been proposed that lowering the concentration of albumin in the dialysate does not seem to affect the detoxification capability of the procedure. Nevertheless, the most widely used systems today are based on hemodialysis and adsorption. These systems use conventional dialysis methods with an albumin containing dialysate that is later regenerated by means of adsorption columns, filled with activated charcoal and ion exchange resins. At present, there are two artificial extracorporeal liver support systems: the Molecular Adsorbents Recirculating System (MARS)10 from Gambro and Fractionated Plasma Separation and Adsorption (FPSA), commercialised as Prometheus (PROM) from Fresenius Medical Care.13 Of the two therapies, MARS is the most frequently studied, and clinically used system to date. MARS was developed by a group of researchers at the University of Rostock (Germany), in 199310 and later commercialized for its clinical use in 1999. The system is able to replace the detoxification function of the liver while minimizing the inconvenience and drawbacks of previously used devices. "In vivo" preliminary investigations indicated the ability of the system to effectively remove bilirubin, biliary salts, free fatty acids and tryptophan while important physiological proteins such as albumin, alpha-1-glicoproteine, alpha 1 antitrypsin, alpha-2-macroglobulin, transferrin, globulin tyrosine, and hormonal systems are unaffected.