AASLD Expert Opinion Updates Liver Biopsy Guidance

The American Association for the Study of Liver Diseases (AASLD) has published its inaugural Expert Practice Opinion (EXPO), updating its liver biopsy guidance for the first time since 2009 and outlining the contemporary role of liver biopsy in clinical practice.¹

EXPOs are “a new type of clinical resource designed to provide timely, expert-informed recommendations for areas of hepatology where evidence is limited, emerging or evolving too rapidly to support a formal GRADE-based Practice Guideline,” AASLD wrote in a statement.²

The document was developed by a writing group appointed by the AASLD Practice Guidelines Committee and published in Hepatology. Unlike AASLD Practice Guidelines, it did not use a systematic review or GRADE methodology. Instead, the writing group did a targeted literature review and drafted expert opinion statements that all members agreed on.¹

When to Consider Liver Biopsy Alongside Noninvasive Testing

The EXPO identifies 3 primary indications for liver biopsy: establishing a diagnosis, staging inflammation and/or fibrosis, and informing clinical management. Its statements say biopsy should be considered when evaluating unexplained abnormal liver tests, when noninvasive fibrosis testing is uncertain or discordant, and when histologic findings will inform management decisions.¹

Examples given include discordant noninvasive results, such as a high FIB-4 and nodular liver with low liver stiffness. Others are patients with autoimmune hepatitis (AIH) considering stopping immunosuppression, liver transplant recipients with abnormal liver tests, and cases where a payer requires biopsy-confirmed fibrosis staging before therapy.¹

The authors also noted biopsy’s limitations. A specimen represents about 1/50,000th of liver volume, and interobserver concordance for fibrosis staging is 78% even among expert pathologists. In 51 patients with metabolic dysfunction–associated steatotic liver disease (MASLD) who had specimens taken from each lobe, 35% had F3 fibrosis in one sample and F0 or F1 in the other.¹

In patients with unexplained liver test elevations, a histopathologic diagnosis is made in 74% to 94% of cases, but normal histology is found in up to 15%.¹

Percutaneous, Transjugular, and EUS-Guided Liver Biopsy

Percutaneous biopsy remains the most common approach and is typically performed by gastroenterologists, hepatologists, or radiologists. The EXPO states that imaging localization should be used immediately before or during percutaneous biopsy in adults.¹

Transjugular liver biopsy (TJLB) can be considered for patients with difficult anatomy, coagulopathy, or ascites, or when hepatic venous pressure gradient (HVPG) measurement is needed.¹

The update formally adds endoscopic ultrasound–guided liver biopsy (EUS-LB) as an option. It can be considered for difficult anatomy, when HVPG measurement is desired, or when endoscopy is also warranted. A meta-analysis of 4 randomized trials (258 patients) found no difference between EUS-LB and percutaneous biopsy in diagnostic accuracy, number of complete portal tracts, specimen length, or adverse events.¹

Available data suggest EUS-LB, percutaneous biopsy, and TJLB have similar safety profiles, though EUS-LB is typically performed under deep sedation.¹

“At the same time, the evolving role of EUS-LB and noninvasive liver disease assessments is reshaping how biopsy and histopathology fit within a broader, increasingly sophisticated approach to evaluating liver disease,” Don C. Rockey, MD, FAASLD, said in a statement.²

The EXPO states that technique selection should depend on local expertise and patient-specific factors, including ascites, coagulopathy, concurrent indications, and patient preference.¹

No Set INR or Platelet Thresholds for Liver Biopsy

Major bleeding after percutaneous biopsy occurs in about 0.3% to 0.6% of patients, and mortality in <0.1%. Pain is the most common complication. Severe pain was the only significant independent predictor of major complications in a multicenter study of 1838 biopsies (HR, 30.6).¹

The authors wrote that high-quality data on coagulation thresholds are scarce. Current evidence does not identify a specific INR cutoff that defines high risk, and the role of prophylactic platelet transfusion is unclear.¹

For patients with severe coagulation or platelet abnormalities, decisions should be individualized in consultation with a hematologist, and TJLB is usually preferred.¹

In a sample of 3636 patients, bleeding risk after percutaneous biopsy did not differ between those who took aspirin within 10 days of the procedure and those who did not.¹

Right-Side Positioning After Liver Biopsy Not Supported by Evidence

The EXPO notes that the traditional practice of placing patients in the right lateral decubitus position after percutaneous biopsy is not supported by evidence. In a trial of 90 patients, those positioned on the right side reported greater pain immediately after biopsy than those positioned supine, with no difference in complication rates. A 2019 trial found patients rated right-side positioning as less acceptable.¹

Specimen Adequacy and Communication With Pathologists

For all biopsy types, the EXPO states that specimens should be >1.5 cm in length. Pathology reports should note whether the specimen contains >11 portal tracts. For TJLB and EUS-LB, the minimum needle size is 19-gauge.¹

Requisitions should include the biopsy indication and a clear clinical question. The authors recommend expert pathologist review when the initial diagnosis is ambiguous or discordant with the clinical picture, when the condition is complex or rare, or when findings will guide high-stakes decisions such as transplantation.¹

Liver Biopsy in Infants and Children

Pediatric indications mirror those in adults. Genetic testing has largely replaced wedge biopsy for suspected metabolic liver disease. In infants, percutaneous biopsy typically requires a transabdominal approach, and EUS-LB has been used safely in children.¹

The EXPO states that technique should be selected based on the amount of tissue needed, patient age and size, sedation needs, anatomy, ascites or coagulopathy, and local expertise.¹

“This EXPO also looks at how we use liver biopsy today, and as well toward the future of liver biopsy, pointing out that advances such as artificial intelligence and multi-omics approaches may further enhance the information we gain from tissue,” Rockey said in a statement.²

References

1. Verna EC, Adler DG, Kappus MR, et al. AASLD EXPO: Liver biopsy. Hepatology. Published online October 7, 2026. doi:10.1097/HEP.0000000000001828

2. AASLD publishes first Expert-Based Practice Opinion (EXPO) on liver biopsy. News release. AASLD. October 15, 2026.