Doctors can obtain a sample of liver tissue during exploratory surgery, but more often they obtain a sample by inserting a hollow needle through the person's skin and into the liver. This type of biopsy procedure is called percutaneous liver biopsy. Another type of biopsy procedure is called transvenous liver biopsy.
Liver biopsy can detect information about the liver that may not be evident from other tests. Doctors commonly use liver biopsy to detect excess fat in the liver (fatty liver), chronic liver inflammation (chronic hepatitis), metabolic liver diseases such as Wilson disease (an excess of copper) and hemochromatosis (iron overload), complications following liver transplantation, and metastatic liver cancer (cancer that has spread to the liver).
Percutaneous liver biopsy can be done as an outpatient procedure. Doctors usually use ultrasonography to locate the liver and to guide the needle in order to obtain a biopsy specimen of an abnormal area. Once doctors identify the desired biopsy site, they anesthetize the person's skin and insert the needle into the liver. The hollow needle comes out with a tiny piece of liver tissue inside it.
After the specimen is obtained, the person remains in the outpatient department for 3 to 4 hours because of a small risk of complications, such as bleeding of the liver. Because bleeding can start up to 15 days after the biopsy, the person is instructed to stay within an hour's drive of the hospital during that period. Complications related to liver biopsy, though infrequent, can cause serious problems; 1 of 10,000 people die as a result of the procedure. Mild pain in the upper right abdomen, sometimes extending to the right shoulder, is common after a liver biopsy and is usually relieved by analgesics.
In another procedure, called transvenous liver biopsy, a catheter is inserted into a neck vein, threaded through the heart, and placed into one of the hepatic veins that drain the liver. A needle on the tip of the catheter is then inserted through the wall of the vein into the liver. This procedure is less likely to injure the liver than is percutaneous liver biopsy. It is especially useful in people whose blood does not clot properly, a complication of severe liver disease.