Lesions not to be biopsied
Focal liver lesions that can be characterised by imaging do not need biopsy confirmation if strictly adhered to certain diagnostic criteria: Haemangioma, Simple cysts, Focal fatty infiltration, Focal fatty sparing.
Situations where the benefit of accepting a non-tissue diagnosis (based on imaging, clinical setting and serum markers) outweighs the risk of biopsy: HCC in a patient with chronic liver disease.
Always search for other more safely accessible sites for biopsy: suspected disseminated disease, tuberculosis, sarcoidosis, malignancy and lymphoma, open biopsy of a significant axillary, supraclavicular or cervical node is always both safer and more reliable than a guided liver biopsy in terms of accurate histology.
ULTRASOUND GUIDED LIVER BIOPSY
Relative contraindications
Coagulopathy - If the lesion is one that cannot be accurately characterised by imaging and if no other more easily accessible site for biopsy is available (i.e. significant axillary, supraclavicular or upper deep cervical neck nodes), hepatic biopsies can be performed safely in patients with coagulopathy after correction with appropriate clotting elements. Large bore needles are not recommended.
Ascites - is not a contraindication to percutaneous liver biopsy. Few studies, which have addressed the safety of performing a liver biopsy in patients with cirrhosis in the presence of ascites, have reported low complication rates.4. Biliary Obstruction - In patients with obstructive jaundice large bore needles (19 gauge or larger) should be avoided.
Coagulopathy assessment
Prothrombin time (PT), partial thromboplastin time (PTT) and platelet count should be obtained prior to biopsy.
When the platelet count is less than 100,000/ml, PT is prolonged by > 3 seconds relative to the control and PTT is prolonged by > 6 relative to control the biopsy, if absolutely necessary, is done after administration of the appropriate clotting elements.
When the coagulopathy is severe in patients with diffuse liver disease, transjugular biopsy is performed.
Anaesthesia:
Mild sedative is given prior to the procedure
Choice of Modality for Image Guidance
Ultrasound guidance is modality of choice whenever the lesion can be seen by ultrasound imaging. Real time guidance during needle placement is helpful in avoiding major portal and hepatic veins.
CT is preferred during drainage tube insertion in the superior segments to avoid transgression of the pleural space.
Needle Selection
Diffuse liver disease, hepatic lymphoma, most focal liver lesions or a hepatic transplant, a large core 18-gauge Tru-Cut needle biopsy is required; theoretically, needles upto 14 gauge can be used.
For lesions coursing through major vessels or bowel, for vascular lesions and in the presence of coagulopathy a non-cutting needle small bore needle such as a Chiba 20-gauge needle should be used.
Technique
Free hand technique or attached needle guide technique.
Lateral or anterolateral, intercostal or sub costal for the right lobe
Anterior for the left lobe.
Biopsy to be performed during suspended respiration.
Always interpose a cuff of normal parenchyma between the liver capsule and the margin of a lesion.
Complications
0.83 % complication rate for fine needles and 1.44% for larger cutting needles.
Minor complications include transient localized discomfort, post procedure pain sufficient to require analgesia, mild transient hypotension.
Major complications include hypotension.
Post Procedure Care
Since symptoms related to significant post biopsy haemorrhage is noted within 3 hours after the procedure the patient has to be monitored during this time.
Accuracy
61% to 100%.
Lower accuracy rates have been obtained with fine-needle aspiration
TRANSJUGULAR LIVER BIOPSY
Indications
Presence of massive ascites
Presence of massive obesity
Severe coagulopathy
Failed percutaneous biopsy
Suspected vascular tumour or peliosis hepatis
Need for ancillary vascular procedures (TIPS, venography)
Contraindications
No major contraindications.
Thrombosis of the internal jugular vein - relative contraindication.
Anaesthesia
Uncooperative and paediatric patients may require anaesthesia.
The procedure is performed under mild sedation. ECG monitors the heart rate and rhythm throughout the procedure, this being important as the right atrium is traversed.
Method
Fasted for four hours.
Supine position with the foot end of the table elevated to distend the jugular vein and also prevent air embolism.
Jugular vein is imaged with high frequency ultrasound, which also helps to define the relation of the carotid artery to the jugular vein.
9 French sheath is introduced into the right jugular vein using the Seldinger technique.
A multipurpose catheter is used to cannulate the right hepatic vein.
A deep inspiration decreasing the angulation of the right hepatic vein with the IVC, improves cannulation.
Hepatic venography is optional and can be done if there is a suspicion of Budd Chiari syndrome.
Over a guide wire introduced into the hepatic vein a metallic introducer is inserted. The metallic cannula has an outer polyurethane sheath. The biopsy needle is introduced through this metallic cannula. The needle should be pointed anteriorly while cutting the tissue.
It is important to do biopsy during suspended respiration.
Since the needle exits the hepatic vein into the liver parenchyma and then cuts the tissue, any bleeding is usually into the venous system.
Care should be taken not to introduce the needle too far into the hepatic vein to avoid traversing the capsule.
The metallic needle is left in place to repeat the biopsy and take more tissue for culture / dry weight copper etc.
The angulation of the right hepatic vein with the IVC might be acute and hinder access with the metallic cannula.
Post Procedure Care :
After removal of the needle and sheath the patient should be nursed in the sitting position for 4 hours. This keeps the jugular vein collapsed and prevents puncture site haematoma formation. The abdominal girth and vital parameters are monitored to check for haemorrhage.
Complications
Perforation of the liver capsule (3.5%)
Intraperitoneal haemorrhage (0.5%)
Transient cardiac arrhythmias
Transient hoarseness or Horner's syndrome caused by local anaesthetic
Haematoma at the puncture site
Puncture of the internal carotid artery
Success Rate
64 to 100% of cases
Aspiration biopsy is 68%
Trucut biopsy is 97%
Reference:
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