Percutaneous Liver Biopsy Technique

Proper identification of the biopsy site is of paramount importance. To choose the site, start with percussion over the right upper quadrant. The biopsy site is usually located in the seventh or eighth intercostal space in the midaxillary line. The site can be further confirmed with either routine ultrasonography (US) or a bedside portable ultrasound machine. ^{[13, 14, 15]} (See the images and video below.) Be sure to ascertain the direction and a safe depth for the biopsy needle. Also, be sure to eliminate the possibility of bowel juxtaposition along the biopsy tract.

Careful percussion can also be used to identify the site. Percuss along the midaxillary line, and identify the point of maximal dullness at the end of maximal expiration by the patient (see the first image below). Once the site is identified—again, usually in either the seventh or the eighth intercostal space, corresponding to the second or third space above the right costal margin—mark it with a surgical pen (see the second image below).

Use the swab sticks to prepare the field. For field preparation, nonsterile gloves may be worn. Apply the povidone-iodine solution in a centrifugal fashion, starting from the mark and moving out in concentric circles (see the image below). Use all three sticks sequentially.

Remove the cover of the biopsy tray to reveal its contents. Check to see that all the necessary items are available. Put on a sterile gown, cap, facial mask, and sterile gloves. Place a sterile drape, found in the biopsy tray (see the image below).

Aspirate lidocaine (1% or 2%) in a syringe (see the image below).

Infiltrate the skin over the site using a 25-gauge needle attached to the lidocaine-filled syringe (see the image below).

Identify the xiphoid process by palpating over the drape, and mark it in some manner (eg, with a piece of gauze; see the image below) so that it can easily be referred to later. Administer further local anesthesia using a 21-gauge needle in both superficial and deeper planes, extending down to the capsule of the liver. The deeper injection should be done while the patient is holding his or her breath in maximal expiration.

Using the second syringe from the tray (see the image below), aspirate a minimum of 7-8 mL of sterile saline.

Unscrew the needle on the second syringe, and attach the liver biopsy needle to this syringe (see the image below).

Using the provided surgical blade, make a small nick at the site so that the biopsy needle can pass more easily through the skin (see the image below). This nick should be made at the upper border of the lower rib in the intercostal space so as to avoid injuring the neurovascular bundle that courses close to the lower border of the ribs.

The guard on the liver biopsy needle may be set beforehand on the basis of the estimated depth required and the safety margin, which is based on the results from US. Direct the needle as dictated by the US findings. If the percussion technique alone was used, the needle should be directed toward the xiphoid process and parallel to the ground. To avoid injury, introduce the biopsy needle in a similar fashion to that described for the blade in the previous step.

After penetrating through the skin and superficial subcutaneous tissues, keep the plunger of the syringe retracted while advancing the needle (see the image below). A series of popping sensations may be felt as the needle passes through the various tissue planes. Flush small amounts of saline once the needle has crossed the tissue planes and is close to the liver capsule to get rid of any tissues that may be blocking the needle tip.

Reapply suction on the needle by pulling back on the syringe plunger, and instruct the patient to exhale completely and hold the breath in maximal exhalation. This expiration is requested to avoid injury to the lungs and the gallbladder, as well as to bring the liver in close proximity to the thoracic wall.

At this time, maintain suction on the syringe while pushing the needle into the liver to the depth and direction estimated previously and then quickly removing it (see the image below). This whole movement should not take more than 1 second and should be smooth both in and out. The needle should make no more than three passes through the liver; a higher number of passes has been associated with increased risk of bleeding. The liver biopsy sample is thus obtained within the saline-filled syringe.

Unscrew the needle from the syringe. Pull the plunger back, and gently take it off the syringe (see in the image below) rather than try to push the specimen forward through the opening of the syringe, which damages the specimen.

Empty the contents of the syringe into the formalin-containing bottle. Notice the liver biopsy sample in the bottle (see the image below, white arrow). Cap the bottle tightly, then look through the side of the bottle to ascertain the approximate size of the sample. A sample about 1.5 cm long and 1-2 mm wide is generally considered adequate.

Label the bottle. A liver biopsy sample thus obtained should be hand-delivered to the pathology laboratory rather than being sent through the pneumatic tube system, so as to avoid the small chance of it getting lost.

Apply pressure to the biopsy site for a few minutes, then apply an adhesive bandage at the site. Instruct the patient to lie on the right side (see the image below) for at least 2 hours.

The postprocedure orders sheet should be filled out at this time. Vital signs (blood pressure, heart rate, and pain level) should be obtained every 15 minutes for the first hour, every 30 minutes for the next hour, and every hour thereafter until discharge. A postprocedure observation time of 2 hours is considered adequate if no complications arise. ^[16] The patient should be observed closely for any symptom or sign of a complication. ^[17]

Pain may develop at the biopsy site or in the right shoulder (referred pain). This is the most common adverse effect, ^[18] occurring in as many as 25% of patients. Treatment should not require more than a single dose of an analgesic

Hypotension is commonly caused by vasovagal reaction and is a frequent cause of hospitalization (together with pain). It may be a sign of hemorrhage.

Hemorrhage ^{[19, 20]}  manifests as hypotension, tachycardia, and abdominal pain, usually within 3-4 hours of biopsy. Postbiopsy bleeding has been reported to occur in as many as 10.9% of cases, though the great majority of studies cite figures lower than 2%. ^[21] Presentations of postbiopsy bleeding include the following:

• Subcapsular hemorrhage (usually asymptomatic; may cause pain)
• Intrahepatic hemorrhage (usually asymptomatic)
• Intraperitoneal hemorrhage (most serious bleeding complication; rare)
• Hemobilia (very rare; four cases in a series of more than 68,000 patients)

In cases where there is increased concern about possible bleeding, plugged percutaneous biopsy, which involves embolization of the biopsy tract, may be considered. ^[22]

Other potential complications are as follows:

• Unintentional biopsy of other organs, such as lung, kidney, or colon (rare)
• Biliary peritonitis (rare)
• Pneumothorax or hemothorax (rare) ^[23]
• Transient bacteremia (mostly inconsequential)
• Death (death rate, one in 10,000-12,000 patients) ^{[24, 25]}

Portal vein thrombosis after percutaneous liver biopsy has also been reported. ^[26]  

Needle-tract seeding is a rare potential complication. ^[27]