Molecular Adsorbent Recirculating System
Reviewed and revised 8th November 2013
OVERVIEW
- Molecular Adsorbent Recirculating System = MARS
- short-term extracorporeal hepatic support
- so-called ‘liver dialysis’
USE
Indications
- acute liver failure
- acute-on-chronic liver failure
- albumin-bound toxins
- intractable pruritis due to cholestasis
- post hepatectomy and post-liver transplant support
- Severe alcoholic steatohepatitis
- Overdoses/intoxication with protein-bound substances
Contra-indications
- active bleeding
- severe coagulopathy
DESCRIPTION
- MARS® is a liver support system that uses an albumin-enriched dialysate to facilitate the removal of albumin-bound toxins
- The system has three different fluid compartments:
— a blood circuit
— a circuit containing 600 ml of 20% human albumin with a charcoal column and an anion exchange resin column
— dialysate circuit
METHOD OF USE
- patient’s blood is dialyzed against 20% human albumin solution across highly permeable membrane
- albumin acts as scavenging molecule to remove protein bound substances normally cleared by the liver
- the dialysate passes through the adsorbent columns and is recycled with regeneration of albumin binding sites
COMPLICATIONS
- similar to CRRT
- lowers platelet count and fibrinogen concentration
EVIDENCE
- High quality evidence is lacking — only underpowered controlled studies and case reports
- Case reports for acute liver failure due to hepatotoxic agents (e.g. acetaminophen, amanita phalloides, amphetamines, antibiotics, and allopurinol)
- Case reports for acute poisonings with highly bound protein substances (e.g phenytoin, lamotrigine, theophylline, calcium channel blockers, and heavy metals)
- MARS use is associated with improvement in hyperbilirubinemia, encephalopathy, and circulatory dysfunction; but no good RCT evidence and mortality data
- Randomized trial (n= 23) of standard medical therapy +/- MARS for acute-on-chronic liver failure (mostly due to alcohol) showed 30 day mortality reduction
OTHER INFORMATION
- expensive
- not available outside specialist centres
- effectiveness and role is still under investigation
Single pass albumin dialysis (SPAD)
- uses standard CVVHD system
- Diluted albumin solution (4.4%) added to dialysis solution
- Albumin rich dialysate is not recycled; discarded after “single pass,” with “clean” albumin continuously introduced to maintain binding site availability
- less well studied than MARS
References and Links
- Boyle M, Kurtovic J, Bihari D, Riordan S, Steiner C. Equipment review: the molecular adsorbents recirculating system (MARS). Crit Care. 2004 Aug;8(4):280-6. PMC522853.
- Collins K, Roberts E, Adeli K, et al. Single pass albumin dialysis (SPAD) in fulminant Wilsonian liver failure: a case report. Pediatr Nephrol 2009; 23: 1013-1016. PMID: 18299897
- Karvellas CJ, Gibney N, Kutsogiannis D, Wendon J, Bain VG. Bench-to-bedside review: current evidence for extracorporeal albumin dialysis systems in liver failure. Crit Care. 2007;11(3):215. PMC2206413.
- Laleman W, Wilmer A, Evenepoel P, Verslype C, Fevery J, Nevens F. Review article: non-biological liver support in liver failure. Aliment Pharmacol Ther. 2006 Feb 1;23(3):351-63. PMID: 16422994.
- Saliba F. The Molecular Adsorbent Recirculating System (MARS) in the intensive care unit: a rescue therapy for patients with hepatic failure. Crit Care. 2006 Feb;10(1):118. PMC1550821.
- Stange J. Extracorporeal liver support. Organogenesis. 2011 Jan-Mar;7(1):64-73. PMC3082035.
- Tan HK. Molecular adsorbent recirculating system (MARS). Ann Acad Med Singapore. 2004 May;33(3):329-35. PMID: 15175774.
- Wauters J, Wilmer A. Albumin dialysis: current practice and future options. Liver Int. 2011 Sep;31 Suppl 3:9-12. PMID: 21824276.
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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