You are in: eMedicine Specialties > Gastroenterology > Liver Diagnostic Liver BiopsyArticle Last Updated: Dec 8, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 7
  Author: Atif Zaman, MD, MPH, Associate Professor, Department of Gastroenterology and Hepatology, Department of Public Health and Preventive Medicine, Oregon Health and Science University Atif Zaman is a member of the following medical societies: American Association for the Study of Liver Diseases, American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, American Society of Gastrointestinal Endoscopy, and Oregon Medical Association Coauthor(s): Kenneth Ingram, PAC, Assistant Professor, Department of Medicine, Division of Gastroenterology and Hepatology, Oregon Health Sciences University; Kenneth D Flora, MD, Adjunct Associate Professor of Medicine, Division of Gastroenterology and Hepatology, Oregon Health Sciences University; Consulting Staff, Department of Gastroenterology, The Oregon Clinic Editors: Robert J Fingerote, MD, MSc, BSc, FRCPC, Consultant, Clinical Evaluation Division, Biologic and Gene Therapies, Directorate Health Canada; Consulting Staff, Department of Medicine, Division of Gastroenterology, York Central Hospital, Richmond Hill, Ontario; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Oscar S Brann, MD, FACP, Associate Clinical Professor, Department of Medicine, University of California at San Diego; Consulting Staff, Mecklenburg Medical Group; Alex J Mechaber, MD, FACP, Assistant Dean for Medical Curriculum, Associate Professor of Medicine, Division of General Internal Medicine, University of Miami Miller School of Medicine; Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine; Consulting Staff, Department of Medicine, Section of Gastroenterology and Hepatology, Hospital of the Medical College of Pennsylvania Author and Editor Disclosure Synonyms and related keywords: liver biopsy, percutaneous liver biopsy, hepatic tissue sampling, hepatic biopsy, liver disease, hepatic disease, hepatic failure, liver failure, liver disease diagnosis, liver disease workup, liver disease work-up, percutaneous suction needle liver biopsy INTRODUCTIONSection 2 of 7
  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. INDICATIONS FOR LIVER BIOPSYSection 3 of 7
Liver biopsy, in combination with history and physical examination data, is a powerful clinical tool for diagnosing and treating liver disease. Indications for obtaining a biopsy specimen are listed in as follows. These are divided according to the type of clinical question framed.
The biopsy specimen may be used to identify or exclude possible etiologies for physical or laboratory abnormalities. Although various disease states may present similarly, diagnostic histologic patterns exist when used in the context of clinical presentation. For example, infiltration of the hepatic parenchyma by fat may exist in diseases due to alcohol abuse, hepatitis C, diabetes, and/or obesity. For each disease state, histologic clues exist that distinguish one from the other. Liver biopsy plays little role in the determination of the organism responsible for systemic infection because blood cultures generally are revealing. The notable exceptions are intrahepatic tuberculosis and Mycobacterium avium complex (MAC). Another indication for biopsy is the determination of the extent of histologic change present in a biopsy specimen. This involves scoring systems for the degrees of inflammation and fibrosis noted by the pathologist. Many systems exist for describing the microscopic findings, ranging from simplistic to complex. The majority of scoring systems report the degree of inflammation as the grade of the disease and the amount of fibrosis as the stage. An example here would be the finding of moderate inflammation (grade 3) in a specimen from a cirrhotic (stage 4) liver. The third set of indications is the monitoring of the progression of disease or of treatment efficacy. For example, liver biopsy specimens frequently are used to evaluate and treat rejection following liver transplantation. Repeated biopsies are used less frequently to monitor progression of diseases such as primary biliary cirrhosis, chronic hepatitis C, or alcoholic liver disease. Regardless of the indication for the biopsy, identifying which information the procedure is anticipated to yield is important. CONTRAINDICATIONS TO LIVER BIOPSYSection 4 of 7
Contraindications to percutaneous liver biopsy are relatively few, but identifying contraindications is important to avoid the major complications associated with the procedure. Contraindications to liver biopsy include the following:
LIVER BIOPSY TECHNIQUESection 5 of 7
As previously mentioned, a variety of needle types is available for obtaining a liver biopsy specimen. Needles may be divided into 3 broad categories—suction needles (Jamshidi, Klatskin, and Menghini), cutting needles (Tru-cut and Vim-Silverman), and spring-loaded cutting needles. Each needle type has proposed advantages and disadvantages. Suction needles are thought to yield desirable sample size but may fragment cirrhotic livers. Conversely, cutting needles do not fragment liver tissue but may deliver inadequate tissue samples. Spring-loaded needles are thought to decrease the amount of time that the needle is in the liver but may increase patient discomfort due to the clicking noise of the triggering mechanism. Needle selection is largely a result of physician preference and experience. Percutaneous suction needle biopsy technique Patient preparation prior to undertaking a liver biopsy is essential. Ideally, education should begin during an office visit prior to the biopsy. Explain the procedure in sufficient detail, with careful attention to anxiety and pain management issues. Discontinue aspirin 1 week prior to the procedure. Nonsteroidal anti-inflammatory drugs should be stopped 3 days prior to the biopsy procedure. The patient may, or may not, be asked to complete an overnight fast. Eating prior to the procedure allows for gallbladder contraction, reducing the risk of gallbladder puncture. An empty stomach may decrease the likelihood of postprocedure nausea and vomiting, however. This is an important consideration because many biopsies are preformed under light sedation. In most instances, the biopsy procedure is undertaken on an outpatient basis, following the recommendations outlined below. American College of Physicians practice guidelines for outpatient liver biopsies
On the day of the biopsy, review recent laboratory evaluation of prothrombin time and complete blood count, including platelets. Explain the procedure to the patient and obtain informed consent. Place the patient supine, remove pillows, and elevate the right arm behind the head. The legs and feet may be angled to the left to further open the right intercostal spaces. Percuss the right trunk to the point of maximum dullness during both inspiration and expiration. This frequently corresponds to a point along the midaxillary line at the second or third intercostal space above the costal margin. Mark this location with a surgical pen or other method. Ultrasound or CT imaging may be useful, particularly if obtaining a biopsy of a particular region or mass within the liver is desired. Some have advocated that all biopsies be performed under ultrasound guidance; however, whether this reduces procedure-related morbidity or is cost effective is controversial. Once a suitable site has been identified, sterile technique is employed. Prepare the field with Betadine solution and place sterile drapes. Administer local anesthesia with 1% lidocaine in both superficial and deep planes. Patients occasionally notice a pain described as burning or shooting in quality that radiates either transversely or to the right shoulder region. This pain is thought to represent contact of the anesthetic with the capsule of the liver. Once adequate anesthesia has been obtained, a small nick in the skin is made with a surgical blade to allow introduction of the biopsy needle. The biopsy needle is introduced within close proximity to the upper aspect of the lower rib to avoid the intercostal nerve and vasculature. As the needle is introduced, a series of several successive "pops" may be felt. Small amounts of saline contained in the syringe are flushed until resistance is encountered. The resistance is the liver edge; at this point, the needle is withdrawn slightly and flushed again to remove debris. Suction is applied to the syringe, and the patient is asked to expire and to hold his/her breath. This shrinks the lung field and minimizes the risk of perforating the gallbladder, while bringing the liver against the thorax wall. The biopsy sample is obtained. Pressure is applied to the site, followed by an adhesive bandage. The patient is rolled onto the right side and instructed to remain in this position for 1 hour to help prevent bleeding or bile leakage. Vital signs are obtained every 15 minutes for the first hour, every 30 minutes during the second hour, and then hourly until discharge. COMPLICATIONS OF LIVER BIOPSYSection 6 of 7
Complications of liver biopsy occur rarely but potentially are lethal. Complications of percutaneous liver biopsy, listed below, outlines those complications most commonly observed in clinical practice. Pain occurs in approximately 30% of patients undergoing a liver biopsy. It often is described as a dull ache in the right upper quadrant or shoulder and typically is relatively short in duration, lasting less than 2 hours. This pain often responds to analgesics. Unrelenting, severe abdominal pain is alarming, possibly indicating a serious complication such as intraperitoneal hemorrhage or biliary leak. Bleeding comprises a second group of complications. Presentations include subcapsular or parenchymal hematoma, hemobilia, or free intraperitoneal hemorrhage. Intrahepatic or subcapsular hematomas are the most common of the bleeding complications and are noted on approximately 23% of ultrasound images obtained following biopsy. Such findings often are incidental, without associated clinical symptoms. They occur at similar rates after either blind or laparoscopy-guided modalities, but incidence may be influenced by needle type and imaging technique. Large hematomas are a rare cause of biliary obstruction. Symptomatic hematomas should be imaged by ultrasound but usually respond to conservative treatment with analgesics. Hemobilia presents as biliary colic, gastrointestinal bleeding, and jaundice. It is a rare complication of biopsy; one study of 68,276 biopsies reported 4 instances of hemobilia. Clinical presentation ranges from chronic anemia to rapid exsanguination. Hemobilia typically develops later than other complications. The average time to onset of symptoms is 5 days following the procedure, but onset may occur earlier. Conservative treatment often is sufficient. However, if clinically significant hemobilia is present, angiography is the modality of choice because both diagnosis and intervention can be accomplished with a single procedure. Biliary peritonitis is another noteworthy complication, although rare. Severe abdominal pain and vasovagal hypotension herald its occurrence. Analgesics and fluid management usually are sufficient, but persistence of the condition may necessitate endoscopic retrograde cholangiopancreatography with stent placement. Intraperitoneal hemorrhage is the most serious of the bleeding complications. It is an early occurrence, most often observed during the first few hours following the procedure, although reports of this complication as long as 24 hours postprocedure have been noted. Late hemorrhage is associated with a poor outcome. The overall rate of occurrence of peritoneal hemorrhage in a large study was 0.32%. Factors associated with increased risk of free bleeding include increased age, hepatic malignancy, multiple needle passes, and cirrhosis. Abdominal pain and persistent hemodynamic instability, presenting as tachycardia and hypotension, are typical of significant bleeding. Early diagnosis via ultrasonography is preferred. Treatment includes aggressive fluid management and blood and platelet transfusion, if indicated. An angiographer and surgeon should be alerted early in the process to facilitate rapid intervention if needed. Angiography with potential embolization is the preferred intervention. Bacteremia, pneumothorax, and accidental biopsy of other organs are rare complications. Their frequencies are outlined below. Complications of percutaneous liver biopsy (Reddy, 1996)
REFERENCESSection 7 of 7
Diagnostic Liver Biopsy excerpt Article Last Updated: Dec 8, 2006 |
