What is the significance of Melanocytic Acquired Reticular Pigmentation of the Skin (MARS) in the gastrointestinal tract?

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Last updated: March 15, 2025View editorial policy

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From the Guidelines

MARS (Molecular Adsorbent Recirculating System) has no significant benefit in improving survival in patients with acute-on-chronic liver failure (ACLF) and should not be recommended for this indication. The use of MARS in the gastrointestinal tract is primarily focused on its application in liver failure, particularly in treating hepatorenal syndrome and hepatic encephalopathy associated with liver dysfunction 1. However, the current evidence suggests that MARS does not improve survival in patients with ACLF, despite its potential benefits in removing albumin-bound toxins that can damage the gastrointestinal tract 1.

The standard MARS treatment regimen typically involves 6-8 hour sessions daily for 3-5 consecutive days, with blood flow rates of 150-250 mL/min, though this may be adjusted based on patient response. MARS works by removing albumin-bound toxins like bilirubin, bile acids, and aromatic amino acids that accumulate during liver failure and can damage the gastrointestinal tract. These toxins contribute to increased intestinal permeability, bacterial translocation, and systemic inflammation.

Some studies have shown promising beneficial effects of MARS in patients with type 1 hepatorenal syndrome (HRS), but these findings need to be further investigated 1. Additionally, a sub-analysis of the Prometheus study showed a beneficial effect on survival in patients with a MELD score higher than 30, which deserves further investigation 1.

In clinical practice, patients undergoing MARS therapy should be closely monitored for hemodynamic stability, electrolyte imbalances, and potential complications such as bleeding or thrombocytopenia. While MARS provides temporary support, it's essential to address the underlying cause of liver dysfunction for long-term management.

Key points to consider when using MARS in the gastrointestinal tract include:

  • MARS is not recommended for improving survival in patients with ACLF
  • MARS may have beneficial effects in patients with type 1 HRS, but further investigation is needed
  • Close monitoring of patients undergoing MARS therapy is crucial to prevent complications
  • Addressing the underlying cause of liver dysfunction is essential for long-term management.

From the Research

Significance of MARS in the Gastrointestinal Tract

There is no direct evidence of Melanocytic Acquired Reticular Pigmentation of the Skin (MARS) in the gastrointestinal tract. However, the provided studies discuss a different concept, Molecular Adsorbent Recirculation System (MARS), which is a form of extracorporeal detoxification system used as an artificial liver support system 2, 3.

MARS as an Artificial Liver Support System

  • MARS is used to remove albumin-bound toxins and improve systemic hemodynamics in patients with liver failure 2.
  • The outcome of patients receiving MARS treatment is difficult to analyze due to the heterogeneity of the patient population and different prognoses 2.
  • MARS is generally a safe procedure, but potential complications and operative issues need to be considered 2.

MARS in Post-Hepatectomy Liver Failure

  • MARS is a potential treatment option for post-hepatectomy liver failure (PHLF), with a 90-day survival rate of 47% in patients treated with MARS 3.
  • Early MARS treatment is safe and feasible in patients with PHLF, but further prospective studies are needed to recommend it as a standard of care 3.

Gut Microbiome and Dysbiosis

  • The gastrointestinal tract is home to trillions of microorganisms, and gut microbiomes play a crucial role in maintaining host-microbial homeostasis 4.
  • Dysbiosis, or an imbalance of the gut's microbial community, is linked to various diseases, including inflammatory bowel diseases, diabetes, and obesity 4.

Bacterial Translocation

  • Bacterial translocation from the gastrointestinal tract to extraintestinal sites can occur through disruption of the ecologic GI equilibrium, increased permeability of the intestinal mucosal barrier, and deficiencies in host immune defenses 5.
  • Indigenous GI bacteria can translocate through the epithelial cells or between them, leading to opportunistic infections 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

MARS in the treatment of liver failure: controversies and evidence.

The International journal of artificial organs, 2006

Research

Systematic review of MARS treatment in post-hepatectomy liver failure.

HPB : the official journal of the International Hepato Pancreato Biliary Association, 2020

Research

Microbiome and Gut Dysbiosis.

Experientia supplementum (2012), 2018

Research

Bacterial translocation from the gastrointestinal tract.

Advances in experimental medicine and biology, 1999

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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