Liver biopsyA liver biopsy is a medical procedure performed to obtain a small piece of liver tissue for diagnostic testing. Liver biopsies are sometimes called percutaneous liver biopsies, because the tissue sample is obtained by going through the patient's
The liver is a very large organ in the right-upper abdomen. In fact, most of the liver lies behind the ribs in the right-lower chest. The liver is remarkable, quietly making many proteins, eliminating waste products, and participating in the general metabolism and nutrition of the body. There are many different problems that can occur in the liver. These include virus infections, reactions to drugs or alcohol, tumors, hereditary conditions, and problems with the body's immune system.
The physician will always take a medical history and perform a physical exam. Blood studies, known as liver function tests (LFT), give an overview of the health of the liver. If LFT results are persistently abnormal, the physician will then perform additional medical studies to determine the exact cause of the problem. This is particularly important because there are now effective treatments for many chronic liver disorders. Finally, the physician will want to know not only the specific cause of the problem, but also the severity of it. The liver biopsy helps answer these questions.
The liver biopsy is a small sample of body tissue. This tissue is prepared and stained in a laboratory. The physician can then view it under a microscope. By so doing, he or she can often make a specific diagnosis and determine the extent and seriousness of the condition. This information is often vital in determining the treatment.
Liver biopsy is often used to diagnose the cause of chronic liver disease that results in elevated liver tests or an enlarged liver. It is also used to diagnose liver tumors identified by imaging tests. In many cases, the specific cause of the chronic liver disease is highly suspected on the basis of blood tests, but a liver biopsy is used to confirm the diagnosis as well as determine the amount of damage to the liver. Liver biopsy is also used after liver transplantation to determine the cause of elevated liver tests and determine if rejection is present.
What are the different ways liver biopsy can be performed?The most common way a liver sample is obtained is a percutaneous liver biopsy procedure, local anesthesia is used to numb the skin where a small incision is made. A needle is then passed through the skin and into the liver, where a specimen is obtained. Multiple biopsies may be taken.
Another technique used for liver biopsy is called percutaneous image-guided liver biopsy which is similar to the one described above except that the needle is guided by CT scan or ultrasound images. This is most helpful when the disease process is localized to discrete spots in the liver.
A laparoscopic liver biopsy may be done solely for the purpose of obtaining the biopsy specimen or may be part of another operative procedure. Small incisions are made in the abdomen and instruments are introduced through trocars to obtain the biopsy specimens. The laparoscope is a telescope that magnifies the objects it sees and allows excellent visualization of the liver surface. Ultrasound can be used as part of this procedure.
Finally, liver biopsy may be done at the time a patient undergoes an open abdominal operation, enabling the surgeon to inspect the liver and take one or more biopsy samples as needed.
What to do before liver biopsy?Liver biopsies require some preparation of the patient. Since aspirin and ibuprofen (Advil, Motrin) are known to thin the blood and lessen clotting function, it is best to avoid these medications for at least a week 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. Blood tests to check for clotting disorders are given to make sure that the patient's clotting factors are within the normal limits. The tests most commonly given to patients scheduled for a liver biopsy are platelet count tests and prothrombin time tests. 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 checked for 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 physical problems.
What is the liver biopsy procedure?Percutaneous liver biopsy is sometimes called aspiration biopsy because it is done with a hollow needle attached to a suction syringe. The special needle that is used to perform a liver biopsy is called a Menghini needle. In many cases the biopsy is done by a doctor who specializes in x rays and imaging studies (a radiologist). The radiologist will use
An hour or so before the biopsy, the patient will be given a sedative to help relaxation. He or she 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 an anesthetic at the biopsy site.
The doctor prepares the Menghini 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 2 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. Pressure is applied at the biopsy site to stop any bleeding and a bandage will be 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 10-15 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.
What's the aftercare for liver biopsy?Liver biopsies are now considered outpatient procedures in most hospitals. Patients are usually discharged four to eight hours after the biopsy. At regular intervals, a nurse checks the patient's vital signs. If there are no complications, the patient is sent home.
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. Tylenol 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.
What're the risks of a liver biopsy?The risks of a liver biopsy are usually very small. When complications do occur, over 90% are apparent within 24 hours after the biopsy. The most significant risk is internal bleeding. Bleeding is most likely to occur in elderly patients, in patients with cirrhosis, or in patients with a tumor that has many blood vessels. 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. In order to reduce the risk of bleeding, the coagulation status is assessed in all patients prior to a biopsy. If the prothrombin (coagulating) time is too slow or the platelet count is low, a standard biopsy is not recommended. Vitamin K or fresh frozen plasma may be used to correct clotting abnormalities in such instances. Another alternative in this situation would be a transjugular biopsy.