Hepatorenal Syndrome

Hepatorenal syndrome (often abbreviated HRS) is a life-threatening medical condition that consists of rapid deterioration in kidney function in individuals with cirrhosis or fulminant liver failure. HRS is usually fatal unless a liver transplant is performed, although various treatments, such as dialysis, can prevent advancement of the condition.

HRS can affect individuals with cirrhosis (regardless of cause), severe alcoholic hepatitis, or fulminant hepatic failure, and usually occurs when liver function deteriorates rapidly because of an acute injury such as an infection, bleeding in the gastrointestinal tract, or overuse of diuretic medications. HRS is a relatively common complication of cirrhosis, occurring in 18% of cirrhotics within one year of their diagnosis, and in 39% of cirrhotics within five years of their diagnosis.

Deteriorating liver function is believed to cause changes in the circulation that supplies the intestines, altering blood flow and blood vessel tone in the kidneys. The renal failure of HRS is a consequence of these changes in blood flow, rather than direct damage to the kidney; the kidneys themselves appear normal to the naked eye and tissue is normal when viewed under the microscope, and the kidneys even function normally when placed in an otherwise healthy environment (such as if transplanted into a person with a healthy liver). The diagnosis of hepatorenal syndrome is based on laboratory tests of individuals susceptible to the condition. Two forms of hepatorenal syndrome have been defined: Type 1 HRS entails a rapidly progressive decline in kidney function, while type 2 HRS is associated with ascites (fluid accumulation in the abdomen) that does not improve with standard diuretic medications.

The risk of death in hepatorenal syndrome is very high; the mortality of individuals with type 1 HRS is over 50% over the short term, as determined by historical case series. The only long-term treatment option for the condition is liver transplantation. While awaiting transplantation, people with HRS often receive other treatments that improve the abnormalities in blood vessel tone, including supportive care with medications, or the insertion of a transjugular intrahepatic portosystemic shunt (TIPS), which is a small shunt placed to reduce blood pressure in the portal vein. Some patients may require hemodialysis to support kidney function, or a newer technique called liver dialysis which uses a dialysis circuit with albumin-bound membranes to bind and remove toxins normally cleared by the liver, providing a means of extracorporeal liver support until transplantation can be performed.