Home > Encyclopedia of Nursing & Allied Health > Liver Biopsy

Definition

A liver biopsy is a medical procedure performed to obtain a small piece of liver tissue for diagnostic testing. The sample is examined under a microscope by a doctor who specializes in the effects of disease on body tissues (a pathologist) to detect abnormalities of the liver. Liver biopsies are sometimes called percutaneous liver biopsies, because the tissue sample is obtained by going through the patient's skin. This is a useful diagnostic procedure with very low risk and little discomfort to the patient.

Purpose

A liver biopsy is usually done to evaluate the extent of damage that has occurred to the liver because of chronic and acute disease processes or toxic injury. Biopsies are often performed to identify abnormalities in liver tissues after imaging studies and radiopharmaceutical scans have failed to yield clear results.

A liver biopsy may be ordered to diagnose or stage any of the following conditions or disorders:

• jaundice
• cirrhosis
• repeated abnormal results from liver function tests
• alcoholic liver disease
• unexplained swelling or enlargement of the liver (hepatomegaly)
• suspected drug-related liver damage such as acetaminophen poisoning
• hemochromatosis, a condition of excess iron in the liver
• intrahepatic cholestasis, the build up of bile in the liver
• hepatitis
• primary cancers of the liver, such as hepatomas, cholangiocarcinomas, and angiosarcomas
• metastatic cancers of the liver (These are over 20 times as common in the United States as primary cancers.)
• post liver transplant to measure graft rejection
• fever of unknown origin
• suspected tuberculosis, sarcoidosis, or amyloidosis

Precautions

When performing the liver biopsy and blood collection that precedes it, the physician and other health care providers should follow universal precautions for the prevention of transmission of bloodborne pathogens. Some patients should not have percutaneous liver biopsies. They include those with any of the following conditions:

• a platelet count below 100,000
• a prothrombin test time greater than three seconds over the reference interval
• a liver tumor with a large number of veins
• a large amount of abdominal fluid (ascites)
• infection anywhere in the lungs, the lining of the chest or abdominal wall, the biliary tract, or the liver
• benign tumors (angiomas) of the liver (These tumors consist mostly of enlarged or newly formed blood vessels and may bleed heavily.)
• biliary obstruction

Description

Percutaneous liver biopsy is sometimes called aspiration biopsy or fine needle aspiration (FNA) because it is done with a hollow needle attached to a suction syringe. The special needles that are used to perform a liver biopsy are called Menghini or Jamshedi needles. The amount of specimen collected should be about 1-2 cc. In many cases the biopsy is done by a doctor who specializes in x rays and imaging studies (a radiologist). The radiologist will use computed tomography scan (CT scan) or ultrasound to guide the needle to the target site for the biopsy. Some ultrasound guided biopsies are performed using a biopsy gun which has a spring mechanism which contains a cutting sheath. This type of procedure gives a greater yield of tissue.

An hour or so before the biopsy, the patient will be given a sedative to aid in relaxation. The patient is then asked to lie on the back with the right elbow to the side and the right hand under the head. The patient is instructed to lie as still as possible during the procedure. He or she is warned to expect a sensation resembling a punch in the right shoulder when the needle passes a certain nerve (the phrenic nerve) but to hold still in spite of the momentary feeling.

Following these instructions to the patient, the doctor marks a spot on the skin where the needle will be inserted. The right side of the upper abdomen is thoroughly cleansed with an antiseptic solution, generally iodine. The patient is then given a local anesthetic at the biopsy site.

The doctor prepares the needle by drawing sterile saline solution into a syringe. The syringe is then attached to the biopsy needle, which is inserted into the patient's chest wall. The doctor then draws the plunger of the syringe back to create a vacuum. At this point the patient is asked to take a deep breath and hold it. The needle is inserted into the liver and withdrawn quickly, usually within two seconds or less. The negative pressure in the syringe draws or pulls a sample of liver tissue into the biopsy needle. As soon as the needle is withdrawn, the patient can breathe normally. This step takes only a few seconds. Pressure is applied at the biopsy site to stop any bleeding and a bandage is placed over it. The liver tissue sample is placed in a cup with a 10% formalin solution and sent to the laboratory immediately. The entire procedure takes 10 to 15 minutes. Test results are usually available within a day.

Most patients experience minor discomfort during the procedure, but not severe pain. Mild medications of a non-aspirin type can be given after the biopsy if the pain lasts for several hours.

Preparation

Liver biopsies require some preparation of the patient. Since aspirin and ibuprofen (Advil, Motrin) are known to inhibit platelets and lessen clotting function, it is best to avoid these medications for at least a week

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KEY TERMS

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Aspiration—The technique of removing a tissue sample for biopsy through a hollow needle attached to a suction syringe.

Bile—Liquid produced by the liver that is excreted into the intestine to aid in the digestion of fats.

Biliary—Relating to bile.

Biopsy—The surgical removal and microscopic examination of living tissue for diagnostic purposes.

Cholestasis—A blockage in the flow of bile.

Cirrhosis—A progressive disease of the liver characterized by the death of liver cells and their replacement with fibrous tissue.

Formalin—A clear solution of diluted formaldehyde that is used to preserve liver biopsy specimens until they can be examined in the laboratory.

Gross inspection—A visual examination of the tissue with the unaided eye performed by a pathologist.

Hepatitis—Inflammation of the liver, caused by infection or toxic injury.

Jaundice—Also termed icterus. An increase in blood bile pigments that are deposited in the skin, eyes, deeper tissue and excretions. The skin and whites of the eye will appear yellow.

Menghini needle/Jamshedi needle—Special needles used to obtain a sample of liver tissue by aspiration.

Percutaneous biopsy—A biopsy in which the needle is inserted and the sample removed through the skin.

Prothrombin test—A common test to measure the amount of time it takes for a patient's blood to clot. Units are in seconds.

Vital signs—A person's essential body functions, usually defined as the pulse, body temperature, and breathing rate. Vital signs are checked periodically during procedures like liver biopsies to make sure that the patient is not having physical problems as a result of the procedure.

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before the biopsy. The doctor should check the patient's records to see whether he or she is taking any other medications that may affect blood clotting. A platelet count (or complete blood count) and prothrombin time are performed prior to the biopsy. These tests determine whether there is an abnormally high risk of uncontrolled bleeding from the biopsy site which may contraindicate the procedure. The patient should limit food or drink for a period of four to eight hours before the biopsy.

Before the procedure, the patient or family member should sign a consent form. The patient will be questioned for any history of allergy to the local anesthetic and asked to empty the bladder so that he or she will be more comfortable during the procedure. His or her pulse rate, temperature, and breathing rate (vital signs) will be noted so that the doctor can tell during the procedure if he or she is having any physical problems.

Aftercare

Liver biopsies are now considered outpatient procedures in most hospitals. Patients are asked to lie on their right sides for one hour and then to rest quietly for three more. At regular intervals, a nurse checks the patient's vital signs. If there are no complications, the patient is sent home but is asked to stay within an hour from the hospital since delayed bleeding may occur.

Patients should arrange to have a friend or relative take them home after discharge. Bed rest for a day is recommended, followed by a week of avoiding heavy work or strenuous exercise. The patient can resume eating a normal diet.

Some mild soreness in the area of the biopsy is normal after the anesthetic wears off. Irritation of the muscle that lies over the liver can also cause mild discomfort in the shoulder for some patients. Acetaminophen can be taken for minor soreness, but aspirin and ibuprofen products are best avoided. The patient should, however, call the doctor if there is severe pain in the abdomen, chest, or shoulder; difficulty breathing; or persistent bleeding. These signs may indicate that there has been leakage of bile into the abdominal cavity, or that air has been introduced into the cavity around the lungs.

Complications

The complications associated with a liver biopsy are usually very small. The most significant risk is prolonged internal bleeding. In about 0.4% of cases, a patient with liver cancer will develop a fatal hemorrhage from a percutaneous biopsy. These fatalities result because some liver tumors are supplied with a large number of blood vessels and bleed very easily. Other complications from percutaneous liver biopsies include the leakage of bile or the introduction of air into the chest cavity (pneumothorax). There is also a small chance that an infection may occur, or an internal organ such as the lung, gall bladder, or kidney could be punctured. This risk is decreased when using the ultrasound or CT guided procedure.

Results

After the biopsy, the liver sample is sent to the pathology laboratory and examined. A normal (negative) result would find no evidence of pathology in the tissue sample. It should be noted that many diseases of the liver are focal and not diffuse; an abnormality may not be detected, if the sample was taken from an unaffected site. If symptoms persist, the patient may need to undergo a repeat biopsy.

The pathologist will perform a gross inspection of the sample to note any changes in appearance. In cirrhosis, the sample will be fragmented and hard. Fatty liver, seen in heavy drinkers, will float in the formalin solution and will be yellow. Carcinomas are white. The pathologist will also look for deposition of bile pigments (green) indicating cholestasis (obstruction of bile flow). In preparation for microscopic examination, the tissue will be frozen and cut into thin sections. These will be mounted on glass slides and stained with various dyes to aid in identifying microscopic structures. Using the microscope, the pathologist will examine the tissue samples, and identify abnormal cells or microarchitecture and any deposited substances such as iron or copper. In liver cancer, small dark malignant cells will be visible within the liver tissue. An infiltration of white blood cells may signal infection. The pathologist also checks for the number of bile ducts and whether they are dilated. He or she also looks at the health of the small arteries and portal veins. Fibrosis will appear as scar tissue and fatty changes are diagnosed by the presence of lipid droplets. Many different findings may be noted and a differential diagnosis (one out of many possibilities) can often be made. In difficult cases, other laboratory tests such as liver function enzymes, will aid the clinician in determining the final diagnosis.

Health care team roles

The liver biopsy requires the skill of many clinicians including the radiologist, hepatologist and pathologist in order to make the diagnosis. Nurses will assist the physician during the biopsy procedure and in caring for the patient after the procedure. Tissues are prepared for microscopic evaluation by a histologic technician.

Patient education

Patients should be told what to expect in the way of discomfort pre-and post-procedure. In addition, they should be advised about what medications they should not take before or after the biopsy. It is important for the clinician to reassure the patient concerning the safety of the procedure.

Jane E. Phillips, PhD