Liver dialysis is an external blood-filtering treatment designed to take over some of the liver’s detoxification work when the organ is failing. Unlike kidney dialysis, which has been a routine therapy for decades, liver dialysis remains a specialized intervention used mainly in critical care settings to buy time while a patient’s liver recovers on its own or a transplant becomes available.
How Liver Dialysis Works
Your liver does something your kidneys don’t: it processes toxins that bind to albumin, a protein in your blood. Water-soluble waste (the kind kidneys filter) passes through standard dialysis membranes easily, but albumin-bound toxins won’t cross those membranes. Liver dialysis systems solve this by using albumin-enriched fluid on the other side of the filter to essentially pull those toxins off the blood’s own albumin molecules.
The most widely used system is called MARS (Molecular Adsorbent Recirculating System). It runs your blood through a special filter where it contacts a solution of concentrated human albumin. That albumin attracts and captures the protein-bound toxins from your blood. The albumin solution then passes through charcoal and resin columns that strip it clean, so it can be recirculated and used again. A separate standard dialysis circuit removes water-soluble waste at the same time. The whole setup has three fluid loops working together: your blood circuit, the albumin circuit, and a conventional dialysis circuit.
A second commercially available system, called Prometheus (or Fractionated Plasma Separation, Adsorption and Dialysis), takes a slightly different approach. It separates a fraction of your blood plasma and runs it directly through adsorption filters before returning it to your body. Both systems clear inflammatory molecules from the blood, though neither has been shown to significantly change overall levels of those molecules in the bloodstream after treatment.
When Liver Dialysis Is Used
Liver dialysis is not a first-line treatment. It enters the picture when standard medical therapy has failed and the patient’s condition is deteriorating toward multi-organ failure. The major triggers for starting treatment include:
- Hepatic encephalopathy: confusion or altered consciousness caused by toxin buildup the failing liver can’t clear
- Hemodynamic collapse: dangerously unstable blood pressure linked to liver failure
- Hepatorenal syndrome: kidney failure developing as a consequence of liver failure
- Cerebral edema: brain swelling from acute liver failure
Acute liver failure, where a previously healthy liver shuts down rapidly (often from drug overdose or viral hepatitis), is one of the most important scenarios for liver dialysis. It can also be used in acute-on-chronic liver failure, where someone with existing liver disease like cirrhosis experiences a sudden worsening. Less common indications include graft failure after a liver transplant, liver failure after partial surgical removal of the liver, and poisoning with substances that bind to albumin in the blood. In patients with severe alcoholic hepatitis, liver dialysis may stabilize things long enough for the patient to enter a rehabilitation program, which is typically required before being listed for transplant.
What Liver Dialysis Can and Cannot Do
The core goal is survival time. Liver dialysis does not cure liver disease. It reduces the toxic burden on your body so that secondary organ failures (kidneys shutting down, brain swelling, cardiovascular collapse) slow or reverse. This creates a window: either the liver regenerates enough to resume its own work, or a donor organ becomes available for transplant.
In some cases, the treatment successfully mitigates encephalopathy and multi-organ failure long enough for the native liver to recover function without a transplant at all. But the clinical evidence for liver dialysis improving long-term survival remains mixed. Neither MARS nor Prometheus is currently recommended by the European Association for the Study of the Liver or the American Association for the Study of Liver Diseases outside of clinical trials for acute or hyperacute liver failure. The systems clearly remove toxins from blood, but large trials haven’t consistently shown that this translates to better overall survival rates.
What Treatment Looks Like
Liver dialysis sessions typically last six to eight hours, though some run longer depending on the severity of the situation. Patients usually receive multiple sessions over several days. Treatment takes place in an intensive care unit, with continuous monitoring of blood pressure, clotting function, and organ status. A large intravenous catheter is placed in a central vein (usually the neck or groin) to allow blood to flow out to the machine and back.
The experience is broadly similar to kidney dialysis from the patient’s perspective: you’re connected to a machine at the bedside while blood circulates through the external circuit and returns to your body. However, liver dialysis patients are generally much sicker than typical kidney dialysis patients, often sedated or in critical condition, so the experience is less about sitting through a session and more about intensive care management.
Risks and Side Effects
Because the blood passes through an external circuit, liver dialysis carries risks common to all extracorporeal blood treatments. Drops in platelet count are frequent, since platelets can be consumed by the filter and tubing. Patients with liver failure already have impaired clotting, so additional platelet loss can increase bleeding risk. Blood pressure instability during treatment is another concern, particularly in patients whose cardiovascular system is already compromised by liver failure.
Infection risk rises with the central venous catheter required for access. Electrolyte imbalances can occur as the dialysis circuits shift fluid and solute levels. These risks are managed in the ICU, but they make liver dialysis a treatment reserved for situations where the danger of doing nothing clearly outweighs the procedural risks.
The Next Generation of Liver Support
Current systems like MARS and Prometheus only handle detoxification. They don’t replicate the liver’s synthetic functions, like producing clotting factors or regulating metabolism. This is a fundamental limitation, and it’s why researchers have been working on bioartificial liver devices that incorporate living liver cells.
In January 2024, a team at the University of Pennsylvania completed the first successful perfusion of a person’s blood through a genetically engineered pig liver outside the body, using a cross-circulation device. The FDA has since approved an investigational application for this pig-liver system to treat critically ill patients with acute-on-chronic liver failure. Separately, a company called Miromatrix has begun recruiting for a clinical trial of a bioartificial liver support system that uses a recellularized liver scaffold connected to a dialysis machine, targeting patients with acute liver failure. These approaches aim to provide not just toxin removal but actual metabolic and synthetic liver function, which could change outcomes significantly if they prove safe and effective in trials.