Ischemic hepatitis is damage throughout the liver caused by an inadequate blood or oxygen supply.
In ischemic hepatitis, liver cells are damaged or die because the liver does not receive enough blood or oxygen.
Ischemic hepatitis differs from other types of hepatitis. Usually, “hepatitis” implies inflammation of the liver, which can have many causes, most commonly a virus (as in hepatitis A or B). However, in ischemic hepatitis, the liver is not inflamed. Rather, liver cell death (necrosis) occurs. The term hepatitis is used because technically, it refers to any disorder in which liver enzymes called aminotransferases leak from damaged liver cells into the blood.
Ischemic hepatitis develops when the liver's requirements for blood, oxygen, or both are not being met.
Decreased blood flow throughout the body is the most common cause for such unmet needs. Blood flow may be decreased by the following:
Decreased oxygen levels in the body, as may result from prolonged, severe respiratory disorders, can also cause ischemic hepatitis.
An increased need for oxygen and blood, as occurs during a severe bodywide infection (sepsis), can contribute to ischemic hepatitis.
Blocked blood vessels can cause hepatic ischemia but only when both the hepatic artery and the portal vein are narrowed or blocked. Ischemia does not develop when only one of these blood vessels is narrowed or blocked because the liver receives blood from both the hepatic artery and portal vein, and the blood vessel that is not blocked continues to supply the liver with blood.
The most common cause of blocked blood vessels is a blood clot. (Blockage by a blood clot is called thrombosis.) Blood clots in the hepatic artery can have many causes, such as the following:
Disorders that make blood more likely to clot (blood clotting disorders) can cause blockages in the hepatic artery or portal vein. These disorders may be inherited or acquired.
Symptoms include nausea and vomiting. The liver may be tender and enlarged. If people already have severe scarring of the liver (cirrhosis), ischemic hepatitis can cause liver failure (see Liver Failure).
Doctors suspect ischemic hepatitis when results of liver function tests (done to determine how well the liver is functioning and whether it is damaged) and/or blood clotting tests are abnormal in people who have a condition that can cause the disorder.
If doctors suspect ischemic hepatitis, they look for a cause. For example, they may do imaging tests to check for a blockage in the hepatic artery These imaging tests include ultrasonography, magnetic resonance imaging (MRI) of blood vessels (magnetic resonance angiography), and arteriography, which involves taking x-rays after a radiopaque dye (which is visible on x-rays) is injected into an artery.
Doctors focus on treating the condition that is reducing blood flow to the liver. If blood flow can be restored, ischemic hepatitis commonly resolves.
Last full review/revision December 2013 by Nicholas T. Orfanidis, MD