Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

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Executive Summary

Liver biopsy remains a critical diagnostic and prognostic tool in clinical practice, particularly when essential information regarding diagnosis, management, or treatment cannot be obtained through non-invasive techniques. While non-invasive serological and imaging technologies have reduced the frequency of biopsies, histopathological interpretation is still required for complex cases, diffuse liver disease assessment, and targeted evaluation of focal lesions.

Critical Takeaways:

  • Technique and Safety: Percutaneous liver biopsy (PLB) is the most common approach, though transvenous (transjugular) routes are preferred for patients with impaired coagulation or ascites. The mortality rate is very low (less than 1 in 1,000), but major bleeding occurs in approximately 0.5% to 2% of cases.

  • Needle Recommendations: For non-lesional (medical) biopsies, a 16-gauge automated cutting-type needle is recommended to ensure a sample of at least 20 mm in length containing at least 11 portal tracts for accurate staging. For percutaneous biopsy of solid lesions, an 18-gauge needle is advised.

  • Hematological Parameters: Traditional measures like International Normalised Ratio (INR) and platelet counts are poor predictors of bleeding risk in liver disease. However, the guidelines recommend a transvenous route if INR is >1.4 for non-lesional biopsies. Platelet counts below 50 x 10⁹/L also suggest a transvenous approach.

  • Imaging Guidance: Routine use of ultrasound assistance or real-time guidance is strongly recommended to identify the optimal biopsy site, avoid adjacent structures, and reduce complications.

  • Patient-Centered Care: Informed consent must be voluntary and supported by both verbal and written information provided in advance. Patients require a minimum of 3 hours of observation post-procedure and must be instructed on activity restrictions for 48 hours.

1. Indications and Purpose of Liver Biopsy

A liver biopsy is justified only when the information gained is valuable for patient management, the procedure is performed safely by a competent operator, and the patient is fully informed.

Primary Purposes:

  • Clarifying diagnosis when non-invasive tests are inconclusive.

  • Determining the severity of liver damage (fibrosis staging) or nature/grade of a tumor.

  • Predicting prognosis for known diagnoses.

  • Informing and monitoring treatment decisions or disease progression.

  • Obtaining tissue for non-histological assessment (e.g., microbiology or biochemical analysis).

  • Supporting ethical research.

2. Clinical Methodologies and Techniques

Percutaneous Liver Biopsy (PLB)

PLB is the standard approach, involving needle insertion through the skin into the liver parenchyma.

  • Image Guidance: The guidelines recommend that all units use image assistance (ultrasound) to minimize complications. Truly "blind" biopsies should only be performed if the liver has been imaged within the preceding three months and no anatomical variants are present.

  • Needle Choice: Automated cutting-type needles are preferred over aspiration needles (like Menghini) because they provide superior sample adequacy.

  • Procedure: Patients should hold their breath in expiration during the biopsy to reduce the risk of pneumothorax or liver laceration.

Transvenous (Transjugular) Biopsy

This route is used when PLB is contraindicated due to bleeding risks or when hepatic vein pressure studies are required.

  • Mechanism: Access is gained via the internal jugular vein (usually the right side) and a catheter is advanced into the hepatic vein.

  • Samples: Specimens are often smaller and more fragmented; therefore, at least two to three passes are typically required.

Alternative Approaches

  • Endoscopic Ultrasound (EUS) Guided: Increasingly used for targeted lesions and parenchymal disease, offering high-resolution imaging and shorter hospital stays, though samples may be smaller than PLB.

  • Laparoscopic Biopsy: Useful for patients with severe coagulopathy or when direct visualization of the liver is necessary. It allows for the coagulation of the biopsy site to control bleeding.

  • Plugged Biopsy: A variation of PLB where the needle track is filled with a pro-hemostatic agent (e.g., gelatine sponge or fibrin sealant) upon withdrawal to prevent bleeding.

3. Risk Management and Complications

While generally safe, liver biopsy is an invasive procedure with inherent risks.

Morbidity and Mortality

  • Bleeding: Minor bleeding occurs in approximately 10.9% of cases, while major bleeding (requiring transfusion or intervention) occurs in <2%.

  • Mortality: Attributable death rates are estimated between 0.01% and 0.1%.

  • Other Risks: Organ perforation (lung, gall bladder, kidney, or colon), sepsis, biliary peritonitis, and pain.

Factors Increasing Risk:

  • Patient Condition: Older age, presence of ascites, infection, or malignancy (particularly for targeted biopsies).

  • Technical Factors: Multiple needle passes (more than two significantly increase risk) and lack of operator experience.

  • Anatomical Issues: Obesity may make percussion difficult, necessitating ultrasound guidance.

Contraindications and Precautions:

  • Biliary Obstruction: Relative contraindication due to the risk of biliary peritonitis; transjugular routes should be used if a biopsy is essential.

  • Amyloidosis: Associated with a higher mortality risk (up to 5% in some series), making the transvenous route safer if systemic diagnosis (via fat/rectal biopsy) is not possible.

  • Pregnancy: Benefits must be balanced against the risk of premature birth.

4. Hematological Considerations

Contemporary understanding suggests that "rebalanced hemostasis" in stable chronic liver disease means traditional tests (INR/Platelets) do not accurately reflect bleeding risk.

Pre-Procedure Thresholds

  • Non-lesional PLB: Recommended transvenous route if INR >1.4.

  • Targeted PLB: An INR of 1.5–2.0 is generally acceptable in stable disease, though risk increases with fibrosis/portal hypertension.

  • Platelets: Transvenous approach is recommended if the count is <50 x 10⁹/L.

  • Fibrinogen: Very high risk if <0.6 g/L.

Medication Management

The following table outlines the recommended discontinuation intervals for elective procedures:

Note on Blood Products: Fresh Frozen Plasma (FFP) is not recommended to correct an INR ≤2.0, as it is largely ineffective and may increase portal pressure, potentially worsening bleeding.

5. Pathological Standards and Reporting

The quality of the biopsy report depends heavily on the quality of the specimen and clinical communication.

Specimen Quality

  • Dimensions: Ideally >20 mm in length and 1 mm in diameter (16G needle).

  • Portal Tracts: Staging accuracy requires at least 11 complete portal tracts. Samples with fewer than six are considered inadequate.

  • Handling: Most samples should be sent free-floating in formalin. If Wilson’s disease is suspected, a separate fresh core is needed for copper estimation.

Reporting Requirements

A high-quality histopathology report must include:

  • Clinical context: The indication for the biopsy.

  • Objective measures: Sample length and the number of portal tracts.

  • Architecture description: Presence of fibrosis, cirrhosis, or parenchymal nodularity.

  • Scoring: Use of recognized scoring systems for fibrosis and inflammation.

  • Storage: Tissue blocks and slides should be stored for 30 years to allow for retrospective review as disease progresses.

6. Clinical Governance and Patient Care

Consent and Communication

The British Liver Trust identifies communication, consent, and post-biopsy information as the three primary areas for improvement.

  • Consent: Must be obtained by a knowledgeable practitioner, ideally days before the procedure, to allow for patient reflection.

  • Language: Information should be verbal and written, avoiding percentages in favor of natural frequencies (e.g., "4 out of 1000 people").

Post-Procedure Observation and Discharge

  • Monitoring: Vital signs every 15 minutes for the first hour, then every 30 minutes for two hours.

  • Discharge Criteria: Hemodynamic stability, stable blood pressure, and absence of significant pain.

  • Recovery Instructions: Patients must not drive or operate machinery for the remainder of the day. Strenuous activity and heavy lifting should be avoided for 48 hours.

Professional Accountability

Biopsy is a multidisciplinary process involving hepatologists, radiologists, and pathologists. Hospitals must ensure:

  • Formal governance frameworks to verify operator competence.

  • Access to interventional radiology for emergency embolization in case of hemorrhage.

  • Specialist pathology review for complex cases (e.g., autoimmune or biliary diseases).