Liver biopsy provides histologic information about liver structure and evidence of liver injury (type and degree, any fibrosis); 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.
Indications
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). Biopsy is especially valuable for detecting infiltrative liver disorders and is required for clarifying allograft problems (ie, ischemic injury, rejection, biliary tract disorders, viral hepatitis) after liver transplantation. Serial biopsies, commonly done over years, may be necessary to monitor disease progression.
Wilson disease, iron in hemochromatosis), can be measured in the biopsy specimen.
Limitations of liver biopsy include
Sampling error
Occasional errors or uncertainty in cases of cholestasis
Need for a skilled histopathologist
Contraindications
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, 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% (1, 2). One common complication is pain at the biopsy site. Major complications (eg, intra-abdominal hemorrhage, bile peritonitis, lacerated liver) develop in about 0.5 to 2% of patients (2). Complications usually become evident within 3 to 4 hours—the recommended period for monitoring patients.
Contraindications references
1. Seeff LB, Everson GT, Morgan TR, et al: Complication rate of percutaneous liver biopsies among persons with advanced chronic liver disease in the HALT-C trial. Clin Gastroenterol Hepatol 8(10):877-883, 2010. doi: 10.1016/j.cgh.2010.03.025
2. West J, Card TR: Reduced mortality rates following elective percutaneous liver biopsies. Gastroenterology 139(4):1230-1237, 2010. doi: 10.1053/j.gastro.2010.06.015
Other routes
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 most patients, but yields smaller tissue samples. Complication rate is low; 0.6% bleed from puncture of the liver capsule (1). This route allows for the simultaneous measurement of intra- and posthepatic venous pressures, which can be useful in the elucidation of portal hypertension.
Occasionally, liver biopsy is done during surgery (eg, laparoscopy); a larger, more targeted tissue sample can then be obtained.
Other routes references
1. Dohan A, Guerrache Y, Dautry R, et al: Major complications due to transjugular liver biopsy: Incidence, management and outcome. Diagn Interv Imaging96(6):571-577, 2015. doi: 10.1016/j.diii.2015.02.006
