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.

CCC 700 6

Critical Care

Compendium

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