Excerpt from Diagnostic Liver Biopsy

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Although practiced for nearly 115 years, liver biopsy still remains the criterion standard in the evaluation of the etiology and extent of disease of the liver. Paul Ehrlich performed a percutaneous liver biopsy in Germany in 1883. In the late 1950s, Menghini developed a 1-second aspiration technique, which led to wider use of the procedure and broadened its applications.

Since Menghini, the evolution of liver biopsy has been extensive. At present, percutaneous biopsies are performed primarily by specialists in gastroenterology/hepatology or by radiologists. A variety of approaches may be utilized for obtaining a liver tissue specimen. These include a blind percutaneous approach after percussion of the chest wall, biopsy under ultrasound or CT guidance, intravascular tissue sampling via the hepatic vein, and intra-abdominal biopsy at laparoscopy or laparotomy.

The choice of one technique over another is based on availability, personal preference, and the clinical situation. Likewise, various needles are available for use, depending upon the approach and physician experience.

Some controversy remains as to what constitutes an adequate liver biopsy for accurate evaluation. In general, a sample of 1.5 cm in length that is 1.2-2 mm in diameter and contains at least 6-8 portal triads is considered adequate. This represents approximately 1/50,000th of the adult liver. Some hepatologists have advocated for samples of 4 cm of tissue to minimize sampling error, while others have found samples of 1 cm to produce minimal interobserver variability.

Although liver biopsy is generally safe and is currently considered the criterion standard for the evaluation of hepatic inflammation and fibrosis, sampling error, rare complications, and occasionally significant patient anxiety do occur. These factors have led to keen interest in the development of noninvasive tests of hepatic fibrosis. Several modalities of these tests are currently under investigation, and 2 serum tests are now commercially available in the United States.

Although these tests hold promise of reducing the need for liver biopsy in the future, most hepatologists feel that their clinical usefulness is limited at this time. The currently available tests appear to perform well at the extreme ends of the spectrum of chronic liver disease, but results vary considerably in the intermediate stages of disease frequently seen in clinical practice. Lack of validation of these tests in the community settings where they would most likely be used is also a potential shortcoming of the current testing methods.

Complications of liver biopsy are rare but potentially lethal. A thorough understanding of the indications, contraindications, techniques, and common complications and their management is imperative. Therefore, the remainder of this article will address these topics individually.

Please click here to view the full topic text: Diagnostic Liver Biopsy