From the Guidelines
There is no liver dialysis because current technology cannot replicate the liver's complex metabolic, synthetic, and detoxification functions outside the body. The liver has over 500 different functions, including protein synthesis, bile production, drug metabolism, glycogen storage, and hormone regulation, which cannot be easily replaced by an external machine 1. Unlike the kidney, which primarily filters blood to remove waste products and excess fluid, the liver's diverse biochemical processes involve intricate cellular mechanisms that current technology cannot adequately reproduce outside the body.
While some temporary liver support systems exist, such as the Molecular Adsorbent Recirculating System (MARS) or bioartificial liver devices, these only provide limited support for specific functions rather than comprehensive replacement 1. They can help remove toxins from the blood but cannot replicate the liver's synthetic capabilities. For example, a study published in 2020 found that MARS and Prometheus systems did not demonstrate any benefit on survival at 28 and 90 days in patients with acute decompensation, although a significant improvement in hepatic encephalopathy and hepatorenal syndrome was seen in a post-hoc analysis using albumin dialysis with MARS versus standard medical therapy 1.
More recent studies, such as the 2022 EASL clinical practice guidelines on the management of hepatic encephalopathy, suggest that albumin dialysis can ameliorate hepatic encephalopathy in patients with liver failure, but the impact on prognosis is uncertain and further study is warranted 1. For patients with severe liver failure, liver transplantation remains the definitive treatment option when medical management is insufficient. It is essential to refer patients to an expert centre at an early stage after decompensation of their cirrhosis to explore the potential interest in liver support systems and provide a "bridge" to final treatment 1.
Key points to consider:
- The liver's complex functions cannot be replicated by current technology
- Temporary liver support systems provide limited support for specific functions
- Liver transplantation is the definitive treatment option for severe liver failure
- Early referral to an expert centre is crucial for patients with cirrhosis decompensation
- Further research is needed to explore the potential interest in liver support systems and their impact on prognosis 1.
From the Research
Liver Dialysis
- There is no established liver dialysis treatment due to the complexity of liver functions and the lack of a suitable replacement for the liver's detoxification and metabolic processes 2.
- Current liver support systems, such as MARS and Prometheus, have failed to show significant survival benefits in patients with acute-on-chronic liver failure, leading to the development of new devices with improved functionality 2, 3.
Alternative Treatments
- N-acetylcysteine (NAC) has been studied as a potential treatment for non-acetaminophen-induced acute liver failure, with some studies suggesting improved transplant-free survival and reduced mortality in specific patient populations 4, 5.
- Albumin dialysis has been shown to be effective in removing albumin-bound molecules, such as bilirubin, and improving hepatic encephalopathy, but its impact on survival is limited 3.
Challenges and Future Directions
- The development of effective liver dialysis or support systems is hindered by the complexity of liver functions and the need for a comprehensive understanding of liver pathogenesis and regeneration 2.
- Ongoing research and advancements in medical supportive care, such as continuous renal replacement therapy and neurologic support, are expected to improve outcomes for patients with acute liver failure 6.