In patients who have underlying liver diseases histological examination of the liver tissue is needed which could play an important role in the diagnosis, prognosis, staging, and management. This tissue is obtained by performing a biopsy of the liver. There are various reasons to obtain a sample of liver tissue. Few of the common indications are listed below:
1) Liver abnormalities (Focal or diffuse)
2) Parenchymal liver disease
3) Chronic abnormal liver tests
4) Detection and staging of adverse effects of drug treatment,
5) Liver status evaluation following transplantation,
6) Acute liver failure evaluation, and
7) Evaluation of fever of unknown origin
The biopsy can be performed by two methods.
Percutaneous liver biopsy:
Under ultrasound guidance, a trocar is introduced into the liver. Through the trocar, a biopsy needle is accessed and samples are obtained. The samples are sent for analysis. Following, the trocar and the needle are removed and hemostasis achieved by manual compression.
Absolute contraindications to percutaneous biopsy:
Transjugular liver biopsy:
Under ultrasound guidance, a small needle is accessed into the Internal jugular vein. Through this a wire is accessed into the IVC. Using a combination of wires and catheters access obtained into the hepatic veins under fluoroscopic guidance. Positions are confirmed by injecting small amount of contrast. Next, a biopsy needle is accessed into the hepatic veins through a plastic tube (sheath) and samples are obtained. The samples are sent for analysis. All the catheters, wires are removed and hemostasis is achieved by manual compression in the neck.
Absolute Contraindications to TJLbx:
The relative limitations of transjugular liver biopsy:
Imaging of the liver with either Ultrasound, CT or MRI imaging.
The imaging is beneficial for observation of the anatomy and pathology of the liver.
The important lab values for the procedure include:
A livery biopsy is a small sample of the liver taken for pathology analysis.
A biopsy is often needed to confirm diagnosis of a specific liver disease.
- Percutaneous liver biopsy
- Transjugular liver biopsy
- Transfemoral liver biopsy (rarely used)
Obtaining a sample of the liver by piercing through the skin directly into the liver. This approach is less invasive and more direct way to obtain a liver biopsy.
However, in some patients with increased risk of bleeding such as poor coagulation, low platelet count, and recent NSAID use like aspirin the risks do not outweigh the benefits. Other contraindications for this approach include a vascular mass in the liver, ascites, or other anatomical considerations that would make it difficult to obtain a direct sample.
Transjugular livery biopsy
A Transjugular liver biopsy is a procedure that allows your doctor to collect samples of liver tissue so that those pieces of tissue may be evaluated by a specialist. The specialist (often a pathologist) can tell if your liver is affected by a number of diseases by looking at the biopsy/liver tissue under a microscope.
The request for a liver biopsy to obtain tissue is usually asked for when your doctor suspects that there is a disease affecting your liver. This suspicion or concern is usually the result of abnormal lab values, often called liver function tests or LFT’s (discovered during blood work) or symptoms that suggest the liver may not be working as it should. However, a TJLB is not the only way to obtain a sample of liver tissue as biopsies may also be performed through your skin directly into your liver. The “transjugular” approach is chosen instead of the “percutaneous” (through skin) route when a patient has too much ascites (fluid in their abdomen, often because of liver disease) or they have problems with bleeding. Bleeding problems or difficulty with clotting/prolonged bleeding are caused by many things including medications you may be taking as well as several other diseases. A diseased or poorly functioning liver is one of those causes of bleeding. Liver dysfunction often leads to an elevated INR (a lab value obtained from testing your blood), which is a measure of how well your blood can clot. The higher the INR number/value the harder it is for someone to stop bleeding. The “transjugular” approach carries a lower risk of bleeding than the “percutaneous” (through skin) approach and therefore is frequently choses for those patients who may have a higher risk of bleeding during the procedure.
As the name implies a transjugular liver biopsy is obtained by going through your jugular vein. The jugular vein is a large vein in your neck that if followed eventually connects to the inside of your liver. The other way to obtain tissue is by going directly through your skin (Percutaneous liver biopsy - PLB) and will accomplish the same thing in the end however, as discussed above, there are usually special reasons to choose a TJLB over a through skin/percutaneous approach. During a TJLB your doctor (an interventional radiologist) will use special devices guided by x-rays and ultrasound. The interventionalist will direct these special devices through your veins and into your liver. Once the device is in a vein that is located inside your liver your doctor/interventionalist will use a special needle to poke through the vein and into the liver that is located just outside. That special needle will bring back with it a sample of your liver. Before inserting the devices into your jugular vein needed to take the biopsy two things will be done for your comfort. The first is that you will be sedated, which will be explained in greater detail below, and secondly your skin will be anaesthetized (made numb) using a medication called lidocaine. After your skin is numb a very small incision will made to allow access into your jugular vein (most commonly this is done on the right side of your neck). After the procedure is over and everything is removed from your vein a small amount of pressure will be held over the incision for a few minutes until there is no signs of bleeding. A small bandage is applied and you will be sent to the recovery room for observation.
The procedure itself may only take 30 minutes to 1 hour however, the patient should expect arrival at least a few hours before the procedure and monitoring for approximately 2 hours after the procedure is complete. All in all as an outpatient the procedure may fill up the better part of your day.
At the start of a Transjugular Liver Biopsy you will have sedation given to you intravenously. There are many types of sedation that are given in a hospital and most commonly for a TJLB the kind of sedation given is called ‘moderate sedation’. This type of sedation is commonly achieved with combining two medications (versed and fentanyl). It is important to note that moderate sedation is different from general anaesthesia. General anaesthesia involves putting a patient completely to sleep and often times requires a tube be inserted into your mouth to help you breath. That level of sedation is not typically required for a TJLB. Moderate sedation, often referred to by patients as a “twilight” sedation uses the combined effects of an anti-anxiety medication (versed; similar in effect to the well known xanax or ativan) and a anti-pain/analgesic medication (fentanyl; similar to but stronger than the well known drug morphine). When combined these drugs have what is known as a synergistic effect on eachother (stronger together than when used alone) that causes patients to feel very relaxed. Many patients will fall asleep during moderate sedation and experience significant amnesia of the entire procedure however, it is not expected that you fall asleep. Moderate sedation is about balance, a balance between patient comfort and patient safety. One of the side effects of the two drugs (versed and fentanyl) when used together is that they can make a patient forget to breathe by decreasing the brains drive to do so reflexively. The other effect that must be managed is the lowering of a patient's blood pressure. Doctors administering moderate sedation have a duty to keep the patient safe before they have the duty to make a patient fall asleep despite many patients desiring to not be awake at all during the procedure.
Bleeding is usually the biggest concern. When compared to the percutaneous (through the skin) approach to biopsying a liver there is less risk of bleeding associated with a TJLB. The reason for this is because the capsule of the liver is not crossed. Although bleeding from the liver is still technically possible with a TJLB the reduction in risk is significant enough to allow people who would not be able to have the percutaneous approach due to their increased risk of bleeding, still have a biopsy performed. Additional risks associated with the administration of sedation exist and are typically addressed the day of the procedure.
Prior to any liver biopsy a blood test is done to determine how well your body can stop bleeding - or said another way, how easily your blood can clot. This ability of the blood to clot is changed or inhibited by many medications such as, but not limited to, aspirin, clopidogrel/plavix, warfarin/coumadin. Such medications are typically to be avoided 3-5 days before the biopsy date. Exactly what medications and how long they should be stopped for will be directed by your doctor performing the procedure. Additionally since you will be sedated for a TJLB it is required that you have not had anything to eat or drink for at least 6 hours before the procedure starts. Certain important details about not eating or drinking, known as fasting, such as the need to take your home medications with small sips of water should be explained in greater detail to you before the procedure date.
After the procedure the small incision in the neck will have pressure applied to it by hand before a bandage is placed in order to help your body stop any bleeding from this area. Continued bleeding from the incision is a risk of the procedure and several steps are taken to reduce that risk. One such step is having you, the patient, sit up straight after the procedure and be closely monitored in a recovery area for approximately 2 hours. Typically your vital signs (blood pressure and heart rate) will be monitored during this recovery period. Additional restrictions on what you can and cannot do in the 24-48 hours after your procedure will be shared with you before leaving the recovery room to be discharged home or return to the hospital.