*5.5.3.1 Molecular adsorbent recirculating system (MARS)*

This purification system allows the elimination of toxins bound to albumin and water-soluble toxins. The blood that is extracted by catheter circulates at a blood flow of 200 ml/min and is placed in contact with the high permeability MARS® FLUX 2.1 filter (60 kD) and 600 ml of dialysate albumin circulates counter currently with pumped 150 ml/min. This recirculated albumin is placed in contact with the diaFLUX 1.8 filter and with the conventional dialysis bath of the Prismaflex System, allowing the elimination of water-soluble molecules, and the regenerated albumin circulates through the activated carbon cartridge (diaMARS® AC250) that captures cationic toxins and then goes to a second resin cartridge (diaMARS® IE250) that captures anionic toxins. The procedure is performed with an average of 8 hours up to date, with the aim of reducing total bilirubin by more than 25% in each session, achieving a reduction in nitrogen and ammonia and reversing encephalopathy (**Figure 5**).

In the FULMAR study [31], a randomized control trial (RCT), a multicenter study that included 102 ALFs on the liver transplant waiting list, of which standard medical treatment (SMT) vs. SMT and MARS were compared, in this study, it was seen that overall survival at 6 months, transplant-free survival at 6 months, and survival at 1 year were not significantly different in both groups, but transplant-free survival was better in those patients who received more than 3 MARS sessions (p = 0.001) when compared to STM. In relation to other outcomes, there was no improvement in encephalopathy between both treatment groups, but a significant decrease in bilirubin, creatinine, and lactate values was achieved compared to SMT, and it is a valuable therapy in patients who are not candidates for liver transplantation.

In the RELIEF study [32], a multicenter RCT, recruited 189 patients with decompensated cirrhosis (total bilirubin > 5 mg/dl, hepatorenal syndrome or hepatic encephalopathy grade II) and compared STM vs MARS and STM treatment, there

#### **Figure 5.**

*Molecular adsorbent recirculating system (MARS). A) Once the patient's blood enters the high permeability (60 kD) MARS® FLUX 2.1 filter, 600 ml of dialysate albumin circulates in a countercurrent direction with pumped 150 ml/min. B) Then, the recirculated albumin is directed to the diaFLUX 1.8 filter and with the conventional dialysis bath of the Prismaflex system, allowing the elimination of water-soluble molecules. C) Next, the regenerated albumin circulates through the activated carbon cartridge (diaMARS® AC250) that captures cationic toxins. D) It is then directed to a second resin cartridge (diaMARS® IE250).*

#### *Artificial Liver Support Systems DOI: http://dx.doi.org/10.5772/intechopen.109843*

were no differences in survival at 28 and 90 days, in the survival analysis by subgroups there were no differences in survival either, without differences in the length of stay in intensive care and hospital stay, but a significant decrease in bilirubin and creatinine values was achieved in favor of therapy MARS. The lack of evidence is attributed, whether it is related to the heterogeneity in the definition of ACLF, small sample size, low dose of therapy, rapid saturation of the cartridges and albumin, or that MARS therapy does not adjust to the severity of many patients.

A meta-analysis published by Arjun Vaid et al. [33] review 10 RCT and one no RCT and use the Jadad scale to assess the quality of the studies, recruited patients, including ALF and ACLF, and receive MARS from one to 10 sessions, lasting between 6 and 8 hours. The outcomes show a significant decrease in bilirubin levels (p = < 0.001), there was also improvement in encephalopathy (p = <0.001), but MARS therapy did not reduce mortality (p = 0.62), in the analysis by subgroups when performing more than three sessions or increasing the concentration of albumin >20%, which did not influence the reduction of mortality.

Rafael Banares et al. [34], published a high-intensity MARS meta-analysis, recruited 285 patients with ACLF and called high-intensity MARS when they received more than 5 sessions. In the high intensity group, 10-day survival (p = 0.001) and 30 days (p = 0.041) is higher and there was a significant decrease in the MELD score, bilirubin, creatinine, and encephalopathy improvement, compared to the low intensity group, when the number of sessions was less than 5 MARS sessions.

One recently published DELPHI consensus of international experts [35] recommends extracorporeal albumin dialysis (ECAD) in the MARS modality should be started in the early stages of grade II encephalopathy or within 24–48 hours of refractory hepatic encephalopathy and when indications for liver transplantation are present and more than 3 sessions lasting 8 hours are recommended. The reported evidence mention improvement in survival at 21 days in ACL due to acetaminophen, but no benefit at 6–12 months. The use of ECAD is not recommended in patients in the late stages of ALF where multiple organ dysfunction is already expressed.
