Although liver biopsy may be an essential part of patient management, it is an invasive procedure with a relatively high risk of complications. Prospective studies have shown that the histological findings after liver biopsy alter treatment in less than one third of cases, although histology may help to establish the diagnosis.
Methods of liver biopsy
Percutaneous liver biopsy
- Transthoracic (transparietal) and subcostal liver biopsy:
- The borders of the liver are usually visualised by ultrasound.
- Guided biopsies are considered safer and more accurate.
- They are usually directed by ultrasound or computer tomography.
- Plugged liver biopsy:
- This is an alternative method for obtaining liver tissue in patients with impaired coagulation where transjugular biopsy is not available.
- At the end of the procedure the puncture tract is closed with Gelfoam® slurry to reduce the risk of bleeding and bile leak.
Transvenous liver biopsy
- For patients with disturbance of clotting, percutaneous liver biopsy is usually avoided because of the risk of bleeding.
- Transjugular: the internal jugular vein is cannulated on the right side and into the hepatic veins and position checked by injection of contrast medium.
- A transjugular liver biopsy is a safe and well-tolerated technique.
- Transfemoral: sometimes a transjugular approach is not possible and a transfemoral route may be used instead.
Endoscopic ultrasound-guided liver biopsy (EUS-LB)
- EUS-LB provides high-resolution image of both lobes of the liver and a biopsy needle can be safely directed into the liver.
- EUS-LB produces specimens at least comparable to, and in some cases better than, percutaneous or transjugular biopsies.
- Widely separated liver regions can be easily sampled with this technique.
- The diagnostic yield of EUS-guided biopsies depends on site, size and characteristics of target tissues as well as technical and procedural factors (type of needle, biopsy technique and material processing).
Laparoscopic liver biopsy
- This is often used to biopsy lesions found fortuitously at routine laparoscopic surgery.
- It has also been used in centres where access to transjugular liver biopsy is not available, for patients with abnormal clotting parameters and also in patients who have a combination of a focal liver lesion and a coagulopathy where a histological diagnosis is essential in the management of that patient.
- Acute hepatitis:
- Liver biopsy is usually not necessary.
- Histology is of value in assessing those patients who will benefit from treatment and their response to it.
- Hepatitis C viral infection:
- Biopsy is at present the only reliable method of assessing the degree of fibrosis and exclusion of other causes for liver damage.
- It may be used to provide an histological assessment of the severity of liver inflammation, potential progression of fibrosis and the presence or absence of cirrhosis (LFTs correlate poorly with both necro-inflammatory and fibrosis scores found on liver biopsy).
- Hepatitis B viral infection:
- Liver biopsy can help identify other causes for liver disease and can be used for grading fibrosis and inflammation.
- Genetic haemochromatosis:
- Liver biopsy is indicated to define or exclude the presence of cirrhosis, in those cases where biochemical and genetic testing do not give a clear diagnosis and where other causes of liver disease need to be excluded.
- Infections and pyrexia of unknown origin (PUO):
- Occasionally, histology and culture of biopsy material can help in the diagnosis of infections such as tuberculosis.
- Cirrhosis: although ultrasound-guided liver biopsy is the gold standard for diagnosis of liver cirrhosis, its invasiveness and sampling bias limit its use.
- Primary biliary cirrhosis:
- There is often no need to do a liver biopsy to make the diagnosis of primary biliary cirrhosis.
- The presence or absence of cirrhosis is of limited prognostic significance.
- Primary sclerosing cholangitis:
- Liver histology may be needed to make the diagnosis of small duct primary sclerosing cholangitis.
- Alcoholic liver disease:
- Liver biopsy can be helpful in determining the degree of liver damage, estimating the reversibility and defining other contributory factors.
- Autoimmune hepatitis:
- Liver biopsy is usually indicated both in the diagnosis and follow-up of patients with autoimmune hepatitis.
- Non-alcoholic liver disease:
- Currently, it is not possible to differentiate fatty liver from non-alcoholic steatohepatitis (NASH) without liver histology.
- Abnormal LFTs of unknown cause:
- This must be taken in context of the clinical situation and other routine investigations.
- In those without a specific diagnosis following imaging and serology, histology may be important in diagnosis and indication of specific management.
- Focal liver lesions:
- Usually unnecessary with modern imaging techniques.
- There is a risk of seeding tumours down the biopsy track but the degree of risk is currently unknown.
- Liver histology is helpful when the nature of the lesion is unknown after imaging.
- Following liver transplantation:
- The use of liver biopsy after liver transplant is increasing.
- Liver biopsy is useful in the diagnosis of invasive cytomegalovirus infection and in assessing rejection and recurrent disease.
- Liver histology is usually necessary to determine the cause of liver test abnormalities following liver transplantation.
- With current imaging techniques (endoscopic retrograde cholangiopancreatography (ERCP) and MRI cholangiography), liver biopsies should not usually be performed when there is biliary obstruction and cholangitis.
- Abnormal coagulation indices:
- The INR should be measured within one week before liver biopsy. It should be performed on the biopsy for jaundiced patients. A percutaneous biopsy will not usually be undertaken if the INR is greater than 1.3.
- Thrombocytopenia: if the platelet count is >60 x 109/L then the biopsy can be safely performed. If the platelet count is 40-60 x 109/L then platelet transfusion may increase the count enough for the biopsy to be performed safely by the percutaneous route. If, however, platelet transfusion does not increase or the platelet count is >40 x 109/L then alternative biopsy methods can be tried.
- Drugs that affect platelet function (such as aspirin or clopidogrel) should be discontinued (where possible) 5-10 days before biopsy.
- Warfarin must be stopped and the INR monitored until it falls to 1.3 or less before the biopsy is undertaken. If warfarin cannot be safely stopped, then anticoagulation should be provided by giving heparin. However, low molecular weight heparin should be stopped 24 hours before the biopsy is performed.
- Ascites: options include total paracentesis prior to performing the percutaneous biopsy, image-guided biopsy, transjugular liver biopsy, or even laparoscopic biopsy.
- Complications are uncommon. Minor pain or discomfort accours in around one third of patients.
- Other complications may include:
- Severe pain (<3%).
- Vasovagal hypotension (<3%).
- Significant haemorrhage (<0.5%).
- Haemobilia (<0.1%).
- Puncture of another organ (<0.1%).
- Death (<0.1%).
Further reading and references
; British Society of Gastroenterology (2004)
; Ultrasound-guided plugged percutaneous biopsy of solid organs in patients with bleeding tendencies. Hong Kong Med J. 2014 Apr20(2):107-12. doi: 10.12809/hkmj133972. Epub 2013 Jul 22.
; Major complications due to transjugular liver biopsy: Incidence, management and outcome. Diagn Interv Imaging. 2015 Jun96(6):571-7. doi: 10.1016/j.diii.2015.02.006. Epub 2015 Mar 12.
; EUS-guided liver biopsy provides diagnostic samples at least comparable with percutaneous or transjugular routes. Gastrointest Endosc. 2015 Aug 21. pii: S0016-5107(15)02797-2. doi: 10.1016/j.gie.2015.08.025.
; Endoscopic ultrasound-guided liver biopsy: a multicenter experience. Endosc Int Open. 2015 Jun3(3):E210-5. doi: 10.1055/s-0034-1391412. Epub 2015 Feb 27.
; Prediction of liver cirrhosis, using diagnostic imaging tools. World J Hepatol. 2015 Aug 187(17):2069-79. doi: 10.4254/wjh.v7.i17.2069.
; Findings of the UK National Audit Evaluating Image-guided or Image-assisted Liver Biopsy. Part II. Minor and Major Complications and Procedure-related Mortality. Radiology. 2013 Jan266(1):226-35. doi: 10.1148/radiol.12120224. Epub 2012 Nov 9.