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What is a liver biopsy

A liver biopsy involves the removal of a piece of tissue from the liver. The biopsy helps diagnose a number of liver diseases.

The procedure also helps in the assessment of the stage (early, advanced) of liver disease. This is especially important in hepatitis C infection.

The liver is a pyramid-shaped organ that lies within the upper right side of the abdomen. In a typical liver biopsy, a needle is inserted through the rib cage or abdominal wall. The needle goes into the liver to take a sample for examination.

The procedure can also be performed by inserting a needle into the jugular vein. A catheter is then passed through the veins, down to the liver, to take the sample.

Alternative Names

Biopsy - liver; Percutaneous biopsy

How the Test is Performed

The test is usually done in the hospital. You may be given a sedative (a medication to calm you) or pain medication by injection before the test. If the biopsy is through the abdominal wall, you will be lying on your back with your right hand under your head. It is important to be as still as possible.

The health care provider will examine the liver and determine the correct spot for the biopsy needle to be inserted. The skin will be cleansed, and a small needle will be used to inject a local anesthetic to numb the area. A small incision (cut) is made, and the biopsy needle is inserted. You will then be instructed to hold your breath while the biopsy is taken. This is to reduce the chance of puncturing the lung or tearing the liver.

The needle is inserted and removed quickly. Pressure will be applied to stop bleeding, and a bandage is placed over the insertion site. Ultrasound is often used to guide the needle.

If the procedure is performed through the jugular vein, you will lie on your back on a table. The internal jugular vein in the neck will be located. The skin will be cleansed, and a small needle will be used to inject a local anesthetic to numb the area. A needle is then inserted to pass a catheter that is moved down to the liver. X-ray equipment will be used to check the location of the catheter. A specialized needle is then used through the catheter to obtain the biopsy sample.

If you receive sedation for this test, you will need someone to drive you home

There are several kinds of biopsy procedures.

Percutaneous biopsy is the most common. The patient will lie on her/his back, placing their right hand above their head. The patient is given a local anesthetic to numb the biopsy area.

A biopsy needle is quickly inserted and removed while the patient holds her/his breath. Ultrasound or CT scan is sometimes used to guide the biopsy needle. This needle is used to remove tissue from the liver.

Because the area is numbed, the patient should only feel a small amount of dull pain and pressure during the biopsy.

Laparoscopic biopsy is performed most often when the doctor needs a sample from a specific part of the liver. Incisions in the abdomen are made to allow small tools to be inserted into the abdominal cavity. The tools allow the doctor to see where the needle is going, and obtain the exact sample he or she needs.

Transvenous biopsy is usually performed in patients who have bleeding problems. A catheter is inserted in the neck vein and threaded into the hepatic vein to the liver, where a sample is obtained with a needle.

How to Prepare for the Test

Tell your health care provider about:

	Bleeding problems you may have
	Drug allergies you may have
	Medications you are taking
	Whether you are pregnant

What to expect before a liver biopsy:

You must sign a consent form. Blood tests are sometimes done to test for your blood's ability to clot. You will be told not eat or drink anything for the 8 hours before the test.

Your doctor will run a series of blood tests and take a complete medical history. In most instances, patients are instructed to stop taking aspirin, ibuprofren, anticoagulants, and possibly other medications for three days to one week leading up to the biopsy. Fasting may be required for the 8 hours prior to the biopsy. In addition to prescription medications you take, tell your doctor about any over-the-counter medicines, vitamins, and supplements you are taking.

After a liver biopsy:

You will be asked to lie on your right side for 1-2 hours after the biopsy. Someone will have to drive you home from the hospital and stay with you through the first night. This is done because any complications that may occur usually develop within several hours after the biopsy.

The American College of Physicians recommends the following for outpatient liver biopsies:

	The patient must remain within 30 minutes of the facility at which the biopsy was performed.
	The patient must be accompanied by a reliable person the first night after the procedure.
	The facility where the biopsy is performed should have an approved blood bank, laboratory, inpatient bed, and personnel available to the patient for at least 6 hours postprocedure.
	Hospitalization should accompany evidence of bleeding, bile leak, pneumothorax, or pain requiring more than one analgesic dose.

Possible complications of a liver biopsy:

Pain and bleeding from the liver (at the site of the biopsy) are the most common complication of a liver biopsy. In most cases the bleeding is not severe enough to require a blood transfusion, however in some cases a transfusion and/or surgery is required to stop the bleeding. The pain is often reported in the right shoulder, not just in the abdomen, and responds well to pain-relievers. Other complications include infection and puncture of the lung or gallbladder. It is important to remember that any surgical procedure carries a risk of complications, and that most often those complications are rare.

Ultrasound-Guided Liver Biopsy in Real Life: Comparison of Same-Day Prebiopsy Versus Real-Time Ultrasound Approach

Posted 09/14/2007

Spilios Manolakopoulos; Christos Triantos; Sotirios Bethanis; Jiannis Theodoropoulos; Jiannis Vlachogiannakos; Evangelos Cholongitas; Markos Sideridis; Calipso Barbatis; Ploutarchos Piperopoulos; Charis Spiliadi; Nikolaos Papadimitriou; Nikolaos Roukounakis; Dimitrios Tzourmakliotis; Alec Avgerinos; Andrew Burroughs

Abstract

Background and Aim: Currently, an increasing number of liver biopsies are performed by radiologists under real-time ultrasound control. A routine ultrasound assessment of a puncture site before performing percutaneous biopsy is reported to increase diagnostic yield and decrease complication rates. It is not clear if real-time ultrasound is superior to marking the puncture site before biopsy as regards reducing biopsy size and avoiding fragmentation and complications. The aim of this study was to compare ultrasound assessment of the puncture site before performing percutaneous liver biopsy with real-time ultrasound liver biopsy for suspected diffuse liver disease.
Methods: Consecutive percutaneous liver biopsies (n = 631) for diffuse liver disease were evaluated. Group A consisted of patients who had real-time guided-ultrasound biopsy performed by radiologists (241 patients; M/F, 35/106; median age 48 year [range, 17-76]; needle 18 G). Group B patients were assessed by radiologists using ultrasound of the puncture site on the same day that biopsies were performed by experienced gastroenterologists/hepatologists on the ward using the marked site (390 patients; M/F, 276/114; median age 43 year [range, 15-75]; needle 16 G).
Results: There were no differences in severity of liver disease, establishing a diagnosis (OR, 1.92 [95% CI, 0.84-4.34]; P = 0.12), length of liver biopsy specimens, number of fragments or complications. Two independent variables were significantly associated with a histological diagnosis: longer biopsy length (P < 0001) and fragment number of two or less (P < 0.001).
Conclusion: Real-time ultrasound did not improve diagnostic yield or result in fewer complications. Marking the puncture site seems adequate and has the practical advantage that it takes up less of the radiologists' time.

Introduction

Traditionally, liver biopsy has been performed by hepatologists or gastroenterologists. Anatomical variation in livers may result in failure to obtain hepatic tissue at liver biopsy without imaging guidance using the so-called blind biopsy.^[1] In everyday clinical practice, an increasing number of liver biopsies are performed by radiologists under ultrasound control.^[2,3] Ultrasonography, as well as being a good screening test for liver disease,^[2] allows selection of the optimal puncture site before performing biopsy. The use of ultrasonography by marking the site for percutaneous biopsy has been reported to increase diagnostic yield and decrease complication rates.^[4]

It is not clear as to whether performing real-time ultrasound (i.e. at the time of liver biopsy) is any more effective than marking the puncture site shortly before biopsy , in terms of biopsy size, fragmentation and complications. Our aim was to assess these factors in a retrospective review of consecutive patients undergoing liver biopsies for suspected liver parenchymal disease

Methods

Patient Selection and Biopsies

Over a period of 10 years (January 1995 to September 2005), we performed percutaneous liver biopsy in 631 consecutive patients at two liver centers in Athens, Greece: Evangelismos General Hospital and Polyclinic General Hospital. All patients gave written informed consent before the procedure. In all patients the indication for biopsy was to establish a diagnosis and to assess severity of a suspected parenchymal chronic liver disease.

Our cohort was divided in two groups: (i) in group A, real-time ultrasound-guided liver biopsy was performed by radiologists (241 patients; M/F, 135/106; median age 48 year (range 17-76). Bard Biopty instrument with a needle of 18 G (Bard Biopsy-Cut biopsy needle, Bard, Murray Hill, NJ, USA) was used (ultrasound devices: GE Logic 9, GE Logic 400 [General Electric, USA], ACUSON 128XP/10 [Acuson, Siemens, Malvern, PA, USA]). All procedures were performed at Evangelismos General Hospital; (ii) in group B an ultrasound identification of a safe biopsy site was performed in the radiological department by a radiologist on the same day as the liver biopsy. The time needed for the patient to be transferred from the radiology department to the ward where the biopsy was performed was approximately between 10 and 35 min. There were 390 patients (M/F, 276/114; median age 43 year [range 15-75]), biopsies were performed using a 16-G Trucut needle (CardinalHeath, McGaw Park, IL, USA). After a plane for optimum direction of the puncture had been selected and a mark placed, the procedure was then undertaken by an experienced gastroenterologist (SM) on the ward using the marked site without the ultrasound facility. All the biopsies in this group of patients were performed at Polyclinic General Hospital.

In both groups a second pass was attempted if the specimen was considered inadequate, by introducing the biopsy needle at the same entry site and redirecting it. Neither group had a third pass attempted. The biopsy procedures and histology were evaluated retrospectively from prospectively collected data at the time of biopsy. The requisite laboratory criteria considered safe for a percutaneous liver biopsy, the liver biopsy procedure itself, as well as the follow-up protocol that was used, have been described elsewhere.^[5] All patients were followed in hospital for 24 h. Further imaging after biopsy was obtained in the case of persistent pain, orthostatic hypotension or decreasing hemoglobin levels.

End Points in the Study

The safety of both techniques of liver biopsy was assessed according to major complications: (i) transfusion of blood; (ii) surgical intervention; and (iii) hospital stay more than 48 h after the procedure. Minor complications were not evaluated as there was inconsistent recording in the notes.

Definitive histological diagnosis was used in order to compare the adequacy of samples between the two groups.

Definitions

Length of biopsy was the aggregate length of all the fragments. The diagnosis was considered definitive if this was stated in the histopathology report or the report contributed to a definitive diagnosis by exclusion of other potential causes of liver disease. Cases in which either the available liver tissue was inadequate or there was no liver tissue at all were considered as having no diagnosis. We did not make any assessment of the histological quality (e.g. number portal tracts).

Statistical Analysis

Analyses were performed in STATA 8.0 (Stata Corporation, College Station, TX, USA). The clinical, biochemical and virologic data are presented as median with range. Continuous variables were compared using the Wilcoxon rank sum test and Mann-Whitney U-test. Categorical variables were compared using X² or Fisher's exact tests as appropriate. Univariate and multivariate logistic regressions were used to address possible relationships between baseline characteristics and the primary outcome. P-values < 0.05 were considered statistically significant. All P-values are two-tailed.

Results

The diagnoses made histologically in the two groups are shown in Table 1 . The patients in both groups were well matched at time of biopsy with respect to proportion of cirrhotics (group A, 62 (25.7%); group B, 84 (21.5%); P = 0.19) and severity of liver disease ( Table 2 ). Patients in group B were younger (group A, 48 (17-76); group B, 43 (15-75); P = 0023) and there was a greater proportion of men (M/F group A, 135/106; group B, 276/114; P < 0.0001).

There was no statistically significant difference in establishing a diagnosis between the two methods (OR, 1.92 [95% CI, 0.84-4.34]; P = 0.12). A definitive pathological diagnosis could not be achieved in eight patients (3.35%) in group A and 24 (6.15%) in group B. No histological diagnosis was possible in eight patients (four in each group) because of excessive fragmentation of the sample, and in 24 (four in group A and 20 in group B) because no liver tissue was obtained. In 15 patients (two in group A) with no liver tissue in the needle a second pass was attempted unsuccessfully, while six refused a second pass. In two patients a second pass was not attempted because of pain post-biopsy. In group A, a second pass was performed in 32 patients (13.3%) and in group B in 48 patients (12.3%; P = 0.42). Twenty-one of 32 (67%) patients with no histological diagnosis were obese (16 were males) and seven were overweight.

There was no difference regarding the length of liver biopsy specimens, whether assessed as means (group A, 1.43 cm ± 0.59 vs group B, 1.43 cm ± 0.61; P = 0.63) or as medians (group A, 1 cm [IQ range 1-2] vs group B, 1 cm [IQ range 1-2]; P = 0.63). There was no difference in the mean number of fragments (group A, 1.41 ± 0.75 vs group B, 1.38 ± 0.87; P = 0.15) or median number (group A, 1 [IQ range 1-2] vs group B, 1 [IQ range 1-1]; P = 0.15).

Using step-wise logistic regression, two independent variables were statistically significantly associated with a confirmed diagnosis: longer biopsy length (P < 0001) and fragment number of two or less (P < 0.001). The interaction of length and fragments was not statistically significant (P = 0.9).

For a biopsy length of more than 1 cm, the likelihood of confirming the diagnosis was 14.72 (95% CI, 1.94-111.72) times higher than if <1 cm (P = 0.009). If the number of fragments at biopsy was three or more, the biopsy was 9.09 times (95% CI, 3.03-24.39; P < 0.001) less likely to be diagnostic.

There was only one major complication consisting of a post-biopsy bleed (group B) in a 25 year old male with chronic hepatitis C requiring 2 units of blood. The histological diagnosis was mild hepatitis without evidence of cirrhosis. There were no deaths.

Discussion

The results of this study confirm that ultrasound-guided liver biopsy is a safe and efficient method in the evaluation of patients with diffuse liver disease. We did not observe any significant difference between the real-time ultrasound biopsy and 'X marks the spot' technique in terms of post-biopsy complications or ability to have a definitive pathological diagnosis. There was, however, a trend toward fewer cases without liver tissue in the biopsy needle in the group of real-time ultrasound, particularly in obese patients.

The wide availability of ultrasonography has changed the practice of performing liver biopsy so that in many centers most biopsies are now carried out under direct ultrasound visualization. Although the benefit of an ultrasound-guided liver biopsy for diffuse disease is not clear, it has been considered safer,^[6-8] more comfortable^[7] and only marginally more expensive^[7] but cost-effective^[9] compared with blind liver biopsies. This change in methodology has had major implications on the training of gastroenterologists in many countries.

The 'X marks the spot' method is a hybrid between 'blind' biopsy and real-time ultrasound-guided biopsy. This has evolved as current clinical practice in centers where gastroenterologists are proficient in ultrasound, or, as in our case, when radiologists do not have sufficient time to perform percutaneous liver biopsies other than for guided biopsies for intrahepatic lesions. Pasha et al. ^[10] are of the opinion that ultrasound performed before biopsy is not as safe as a real-time ultrasound-guided biopsy as the patient may move prior to the biopsy and intrahepatic vessels cannot be avoided, but did not present data to support this. In contrast to this opinion, our data have shown that major complications following biopsy and the efficacy in establishing pathological diagnosis do not differ between the two techniques.

It may be argued that real-time ultrasound might be superior in terms of obtaining an adequate biopsy sample; no liver tissue was obtained in 20 patients in the 'X marks the spot' technique compared with four in the real-time ultrasound group. We re-examined the records of the above patients and we found that the vast majority were obese or overweight at the time the biopsy was undertaken. Real-time ultrasound-guided biopsy may be the preferred method in obese patients, but transjugular biopsy may be even better.^[11] It may be that caution exercised in judging the depth of insertion of the needle during 'blind biopsy' results in inadequate specimens, compared with the real-time technique. Another advantage of real-time ultrasound is that the biopsy obtained is less likely to be subcapsular in location and thus avoids some histological difficulty in assessing fibrosis; however, we did not have sufficient information to compare the two biopsy techniques for this parameter.

Recently it has been reported^[12] that the size of liver biopsy strongly influences the grading and staging of chronic viral hepatitis. It has been proposed that a liver biopsy should be at least 2.5 cm in length to reduce the sampling error.^[13] In our patients, the size of biopsy specimen was similar to other series^[6,14,15] and is thus consistent with clinical practice in several different countries. However, only seven (2.9%) biopsy samples in group A and nine (2.3%) in group B were ≥2.5 cm, and only 25 (10.3%) in group A and 39 (10%) in group B were ≥2.0 cm. The average length was below this partly due to the fact that 25.4% had cirrhosis. In non-cirrhotic patients in our series who had chronic hepatitis, the median biopsy specimen length was 1.4 cm (0.4-3.1); in group A it was 1.3 cm (0.5-2.5) and in group B it was 1.5 cm (0.4-3.1; P = 0.09). The proposed optimal criteria for biopsy length was obtained in only 14% of those with chronic hepatitis.^[16] In a recent systematic review^[11] of length and number of portal tracts obtained with percutaneous liver biopsy, which evaluated 162 studies, the mean length was 13.6 ± 3.2 mm using a Trucut needle with ultrasound guidance.

A potential bias in interpreting the results in our comparative study is that in group A the needle was 18 G and in group B, 16 G. It could be argued that the ability to confirm diagnosis would favor group B. Rocken et al.^[17] evaluated whether thin-needle biopsy gave enough material to study parenchymal diseases. The histopathological diagnoses showed no major differences between 17-G and 20-G needles across all etiologies of liver disease. Recent data show that mean length does not vary significantly with respect to needle diameter,^[11] therefore the different in needle size is unlikely to have biased our interpretation of the results with respect to ultrasound technique. The number of portal tracts is likely to be affected by the gauge of the needle, but in our study, diagnosis rates were not lower in the group with the 18-G needle versus the 16-G needle. Radiologists most often use an 18-G needle as this is satisfactory for biopsy specimens of non-hepatic tissue.

It is unlikely that the difference in size of needle affected complications which are rare.^[18] In our group B only one patient had hemoperitoneum similar to other series.^[4,19] It is well documented that 60% of complications occur during the first 2 h post-biopsy,^[19] so that rapid transfer is needed, if real-time ultrasound technique is used for the patient to have appropriate monitoring on the ward.^[20]

Our data show that both methods of liver biopsy using ultrasound are equally effective and safe; however, there are some disadvantages of real-time ultrasound biopsy performed by radiologists in the radiology suite, which is increasingly more commonplace.^[2,3] First, the time needed to transfer the patient from the radiology department to the ward or monitoring area, and secondly, increasing the workload of radiologists. Gastroenterologists or hepatologists either using 'X marks the spot' technique if they have insufficient ultrasound training, or they themselves using real-time ultrasound on the ward would relieve radiologists' time, and provide adequate specimens for histological diagnosis. Length of specimens obtained by either technique is the major limiting factor in achieving an adequate diagnosis, as has been documented in the literature.^[11] In obese patients, real-time ultrasound may be preferable as in our study, fewer inadequate specimens were obtained.

http://www.medscape.com/viewarticle/561875_4