Liver biopsy provides histologic information about liver structure and evidence of liver injury (type and degree, any fibrosis Hepatic Fibrosis Hepatic fibrosis is overly exuberant wound healing in which excessive connective tissue builds up in the liver. The extracellular matrix is overproduced, degraded deficiently, or both. The trigger... read more ); this information can be essential not only to diagnosis but also to staging, prognosis, and management. Although only a small core of tissue is obtained, it is usually representative, even for focal lesions.
Percutaneous liver biopsy is usually done at the bedside with ultrasound guidance. Ultrasound guidance is preferred because its use provides the opportunity to visualize the liver and target focal lesions.
Generally, biopsy is indicated for suspected liver abnormalities that are not identified by less invasive methods or that require histopathology for staging (see table Indications for Liver Biopsy Indications for Liver Biopsy* ). Biopsy is especially valuable for detecting infiltrative liver disorders and for clarifying allograft problems (ie, ischemic injury, rejection, biliary tract disorders, viral hepatitis) after liver transplantation Liver Transplantation Liver transplantation is the 2nd most common type of solid organ transplantation. (See also Overview of Transplantation.) Indications for liver transplantation include Cirrhosis (70% of transplantations... read more . Serial biopsies, commonly done over years, may be necessary to monitor disease progression.
Gross examination and histopathology are often definitive. Cytology (fine-needle aspiration), frozen section, and culture may be useful for selected patients. Metal content (eg, copper in suspected Wilson disease Wilson Disease Wilson disease results in accumulation of copper in the liver and other organs. Hepatic or neurologic symptoms develop. Diagnosis is based on a low serum ceruloplasmin level, high urinary excretion... read more , iron in hemochromatosis Hereditary Hemochromatosis Hereditary hemochromatosis is a genetic disorder characterized by excessive iron (Fe) accumulation that results in tissue damage. Manifestations can include systemic symptoms, liver disorders... read more ) can be measured in the biopsy specimen.
Limitations of liver biopsy include
Occasional errors or uncertainty in cases of cholestasis
Need for a skilled histopathologist
Absolute contraindications to liver biopsy include
Patient’s inability to remain still and to maintain brief expiration for the procedure
Suspected vascular lesion (eg, hemangioma)
Altered coagulation/hemostasis status
Severe hypofibrinogenemia (as in the case of disseminated intravascular coagulation [DIC])
Determination of the procedural-related bleeding risk is complex and should be individualized, as classical markers of hemostasis (platelet count, international normalized ratio [INR]) have been shown to inaccurately predict bleeding tendency in patients with advanced liver disease. For this reason, current guidelines do not specify parameter cutoffs prior to liver biopsy (either percutaneous or transvenous). Viscoelastic assays may also be used to assess hemostatic status in patients with liver disease, though validated cutoffs for bedside procedures, including liver biopsy, have not been established
Relative contraindications include profound anemia, peritonitis, ascites Ascites Ascites is free fluid in the peritoneal cavity. The most common cause is portal hypertension. Symptoms usually result from abdominal distention. Diagnosis is based on physical examination and... read more , high-grade biliary obstruction, and a subphrenic or right pleural infection or effusion. Nonetheless, percutaneous liver biopsy is sufficiently safe to be done on an outpatient basis. Associated mortality is about 0.01%. Major complications (eg, intra-abdominal hemorrhage, bile peritonitis, lacerated liver) develop in about 2% of patients. Complications usually become evident within 3 to 4 hours—the recommended period for monitoring patients.
Transjugular venous biopsy of the liver is more invasive than the percutaneous route; it is reserved for patients with a severe coagulopathy, ascites, and/or centripetal adiposity. The procedure involves cannulating the right internal jugular vein and passing a catheter through the inferior vena cava into the hepatic vein. A fine needle is then advanced through the hepatic vein into the liver. Biopsy is successful in > 95% of patients. Complication rate is low; 0.2% bleed from puncture of the liver capsule. This route allows for the simultaneous measurement of intra- and post-hepatic venous pressures, which can be useful in the elucidation of portal hypertension Portal Hypertension Portal hypertension is elevated pressure in the portal vein. It is caused most often by cirrhosis (in developed countries), schistosomiasis (in endemic areas), or hepatic vascular abnormalities... read more .
Occasionally, liver biopsy is done during surgery (eg, laparoscopy); a larger, more targeted tissue sample can then be obtained.