mars system components combined mars and prismaflex monitors mars is an extracorporeal hemodialysis system composed of three different circuits: blood, albumin and low-flux dialysis. the blood circuit uses a double lumen catheter and a conventional hemodialysis device to pump the patient's blood into the mars flux, a biocompatible polysulfone high-flux dialyser. with a membrane surface area of 2.1 m2, 100 nm of thickness and a cut-off of 50 kda, the marsflux is essential to retaining the albumin in the dialysate. blood is dialysed against a human serum albumin (hsa) dialysate solution that allows blood detoxification of both water-soluble and protein-bound toxins, by means of the presence of albumin in the dialysate (albumin dialysis). the albumin dialysate is then regenerated in a close loop in the mars circuit by passing through the fibres of the low-flux diaflux filter, to clear water-soluble toxins and provide electrolyte/acid-base balance, by a standard dialysis fluid. next, the albumin dialysate passes through two different adsorption columns; protein-bound substances are removed by the diamars ac250, containing activated charcoal and anionic substances are removed by the diamars ie250, filled with cholestyramine, an anion-exchange resin. the albumin solution is then ready to initiate another detoxifying cycle of the patient's blood that can be sustained until both adsorption columns are saturated, eliminating the need to continuously infuse albumin into the system during treatment (fig. 1). albumin dialysis circuit figure 1: the mars system results published in the literature with the mars system a systematic review of the literature from 1999 to june 2011 was performed in the following databases: specialized in systematic reviews: cochrane library plus and nhs centre database for reviews and dissemination (hta, dare and nhseed). general databases: medline, pubmed and embase. on-going clinical trials and research project databases: clinical trials registry (national institutes of health, ee.uu.) and health services research projects in progress. general web searching engines: scholar google. effects of mars treatment on hepatic encephalopathy (he) hepatic encephalopathy (he) represents one of the more serious extrahepatic complications associated with liver dysfunction. neuro-psychiatric manifestations of he affect consciousness and behaviour. evidence suggests that he develops as some neurotoxins and neuro active substances, produced after hepatocellular breakdown, accumulates in the brain as a consequence of a portosystemic shunt and the limited detoxification capability of the liver. substances involved are ammonia, manganese, aromatic aminoacids, mercaptans, phenols, medium chain fatty acids, bilirubin, endogenous benzodiazepines, etc. the relationship between ammonia neurotoxicity and he was first described in animal studies by pavlov et al. subsequently, several studies in either animals or humans have confirmed that, a ratio in ammonia concentration higher than 2 mm between the brain and blood stream, causes he, and even a comatose state when the value is greater than 5 mm. some investigators have also reported a decrease in serum ammonia following a mars treatment (table 3). table 3. clinical studies showing some improvement in the treatment of he following a mars treatment