Rapid Communication Open Access
Copyright ©2007 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 28, 2007; 13(40): 5336-5342
Published online Oct 28, 2007. doi: 10.3748/wjg.v13.i40.5336
Liver biopsy in a district general hospital: Changes over two decades
Wing-Kin Syn, Liver and Hepatobiliary Unit, Queen Elizabeth Hospital, Birmingham, B15 2TH, United Kingdom
Caroline Bruckner-Holt, Jeffrey Bateman, Department of Gastroenterology, Princess Royal Hospital, Telford, United Kingdom
Adam Farmer, Department of Gastroenterology, City Hospital, Birmingham, United Kingdom
Sarah Howdle, Department of Radiology, Princess Royal Hospital, Telford, United Kingdom
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Wing-Kin Syn, Liver and Hepatobiliary Unit, Queen Elizabeth Hospital, Birmingham, B15 2TH, United Kingdom. wsyn@doctors.org.uk
Telephone: +44-121-4721311-3414 Fax: +44-121-6272449
Received: June 20, 2007
Revised: August 17, 2007
Accepted: September 12, 2007
Published online: October 28, 2007

Abstract

AIM: To study liver biopsy practice over two decades in a district general hospital in the United Kingdom.

METHODS: We identified all patients who had at least one liver biopsy between 1986 and 2006 from the databases of the radiology and gastroenterology departments. Subjects with incomplete clinical data were excluded from the study.

RESULTS: A total of 103 liver biopsies were performed. Clinical data was available for 88 patients, with 95 biopsies. Between 1986 and 1996, 18 (95%) out of the 19 liver biopsies performed were blind and 6 (33%) were for primary biliary cirrhosis. Between 1996 and 2006, 14 (18%) out of 76 biopsies were blind; and the indications were abnormal liver tests (33%), hepatitis C (12%) and targeted-biopsies (11%). Liver biopsies were unhelpful in 5 (5%) subjects. Pain was the most common complication of liver biopsy (5%). No biopsy-related mortality was reported. There was a trend towards more technical failures and complications with the blind biopsy technique.

CONCLUSION: Liver biopsies performed in small district hospitals are safe and useful for diagnostic and staging purposes. Abnormal liver tests, non-alcoholic fatty liver disease and targeted biopsies are increasingly common indications. Ultrasound-guided liver biopsies are now the preferred method and are associated with fewer complications.

Key Words: Complication; District general; Indication; Liver biopsy; Non-alcoholic fatty liver



INTRODUCTION

Since the first reported percutaneous liver biopsy in 1923, the liver biopsy has become widely used in the investigation of liver disease and is currently the gold standard for confirming the diagnosis and for staging of liver disease[1]. However, it remains an invasive procedure, with a mortality risk ranging between 0.01% and 0.17%[2]. Studies have shown that less than one-third of the biopsies altered the treatment[3]; hence biopsies should only be performed in patients who would benefit from this procedure.

Over the last few decades, there has been a significant improvement in diagnostic and imaging techniques, as well as in the drug therapy of liver disease[1]. These have led to changes in our management of liver diseases. At the same time, changes in socio-economic status and life-style, have resulted in increased prevalence of obesity[4,5] and rising incidence of non-insulin diabetes mellitus[6,7]. Non-alcoholic steatohepatitis (NASH), the hepatic manifestation of the metabolic syndrome or insulin-resistant state[8], is now one of the most common indications for liver transplantation in the USA[9]. Consequently, the indications for liver biopsies in the UK will be expected to evolve over time.

We reviewed all liver biopsies performed in a single district general hospital (DGH) in the UK over two decades. We examined the indications, findings and complications of liver biopsy and explored the changes in our practice over the last two decades.

MATERIALS AND METHODS
Patients

All patients who had a liver biopsy were identified from the databases of the radiology and gastroenterology departments. Relevant clinical and laboratory information was collected retrospectively. Patients whose clinical information was incomplete were excluded from the analysis.

Liver biopsy protocol

In the absence of any contraindications, liver biopsies were performed when clinically indicated, as determined by the supervising clinician. The clinician performing the biopsy obtained an informed consent.

A full blood count (FBC) and clotting profile were obtained one day prior to the biopsy to ensure that the platelet counts were > 80000/mm3 and the international normalized ratio (INR) was < 1.3[1,2,10]. Appropriate platelet and clotting factors were given as necessary. An abdominal ultrasound of the liver was performed within six months of biopsy to ensure that there were no anatomical variants, biliary dilatation or focal or cystic lesions that may require a targeted biopsy[1,11]. The presence of moderate to severe ascites was considered a contraindication to percutaneous biopsy[1]. If considered safe and feasible, patients with massive ascites underwent paracentesis until completely dry, prior to the liver biopsy.

All liver biopsies were performed either as a 'blind' procedure or under ultrasound (USS)-guidance, depending on the personal preference of the clinician or the availability of a radiologist. Patients were discharged after six hours if the procedure was uncomplicated, and if the patient was clinically stable and pain free. A transjugular liver biopsy (TJB) was performed in patients with contraindications to a percutaneous biopsy.

Liver biochemistry, serology and immunology

All patients had liver biochemistry (serum bilirubin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glutamyltransferase (GGT)) taken at the time of the initial clinical assessment. The normal ranges of these tests were: INR, 1; platelets 150-500 × 109/L; bilirubin, 1-17 μmol/L; ALT, 10-31 U/L; ALP, 45-145 U/L; GGT 0-50 U/L. Serum aspartate transaminase (AST) is not part of the routine liver panel at our centre. A liver screen comprising of immunological tests (anti-nuclear antibodies, anti-mitochondrial antibodies, anti-smooth muscle antibodies) for autoimmune diseases, serological tests for hepatitis B and C viruses (hepatitis B surface antigen, anti-hepatitis C antibodies) and serum levels for metabolic disease (ceruloplasmin, alpha-1 antitrypsin, ferritin) was performed in all patients with abnormal liver biochemistry or abnormal USS. Patients with elevated ferritin levels had additional blood samples taken for haemochromatosis gene (C282Y/H63D) mutation analysis.

Usefulness of liver biopsy

In the present study, the usefulness of a liver biopsy was determined qualitatively by a) the success in establishing the diagnosis and/or b) any change (s) in the management based on the results of the liver biopsy

RESULTS
Patient population

A total of 103 liver biopsies were obtained between 1986 and 2006. Clinical data was available on 88 patients who had 95 biopsies. The number of successful liver biopsies was 91; 88 had one biopsy, 7 (4 failed 1st attempt; 3 follow-up biopsies) had two biopsies, while none of the subjects had > 2 biopsies. The median age of the patients was 57 (range, 25-86) years; 51 patients were female. 5 patients had acute hepatitis and 8 patients had focal lesions in the liver on abdominal imaging. The remaining patients underwent staging biopsies or diagnostic biopsies for chronic hepatitis or chronic elevations in liver function tests.

Liver function tests, platelets and clotting profile

The median INR was 1 (range 0.9-1.6). All patients had platelet levels > 80000/mm3 (median 239; range 93-813). The median values of the liver tests were as follows: ALT 66.5 (range 11-1103) U/L, ALP 145 (range 44-994) U/L, GGT 221 (range 20-1394) U/L and bilirubin 13 (range 5-430) μmol/L (Table 1).

Table 1 Patient demographics and clinical features.
Median values (range)Normal values
Age (yr)57 (25-86)
Sex (F/M)51:37
Liver biochemistry
ALT (U/L)66.5 (11-1103)10-31
Bilirubin (μmol/L)13 (5-430)1-17
GGT (U/L)221 (20-1394)0-50
ALP (U/L)145 (44-994)45-145
Platelets (× 109/L)239 (93-813)150-500
Indications for biopsy:
Acute hepatitis5
Chronic hepatitis/Chronic elevated liver tests/Staging of disease75
Abnormal imaging8
Disease follow-up3
Routes of biopsy:
Blind32 (31)
USS guided60 (11)
TJB2
Laparoscopic1
Liver biopsy

Between 1986 and 1996: Number of patients and approach used: Eighteen patients underwent 19 biopsies. One biopsy was USS-guided and 18 were 'blind' biopsies (94.7%). One patient needed a repeat biopsy because of inadequate sample (blind) at the first attempt. The median size of liver biopsies was 1.5 cm (range: 0.5-2.5) (Table 2).

Table 2 Liver biopsies between 1986 and 1995.
Number of successful liver biopsiesDiagnosis pre-biopsyHistoryAbnormal liver testsViral serologyAutoimmune /ImmunoglobulinsImagingOthersFinal Diagnosis
6PBCYYNYNormaln/aPBC
3AIHNYNYNormaln/aAIH: 3 (staging)
1LKM hepatitisNYNY LKM + AMASpleen +n/aPossible overlap AIH/PBC
3ALDYYNNNormal/Spleen +n/aALD: 3 (cirrhosis in 1)
3Abnormal Liver testsNYNNEchogenic liverElevated ferritinNAFLD (simple steatosis): 3
1ALD/Iron overloadYYNNNormalElevated ferritinPorphyria cutanea tarda (plasma porphyrin 618, faecal porphyrin +)
1Iron overloadNYNNNormalElevated ferritin and homozygous C282YPrimary haemochromatosis

Liver biopsy findings: One-third of biopsies were performed for primary biliary cirrhosis (PBC). Two patients had elevated serum ferritin levels but only one was homozygous for the C282Y haemochromatosis mutation. Liver biopsy of the second patient showed features of porphyria cutanea tarda that was confirmed on faecal and plasma porphyrin tests.

Between 1996 and 2006: Number of patients and approach used: A total of 70 patients underwent 76 liver biopsies; 59 biopsies were USS-guided and 14 (18.4%) were 'blind' procedures. Two patients had contraindications to a percutaneous biopsy (one had large volume ascites with raised INR and one had elevated INR), and underwent TJB. Laparoscopic liver biopsy was performed in one patient during laparoscopy performed for abdominal pain. Three patients needed a second biopsy after a failed initial attempt (2 blind, 1 USS-guided) while a further 3 had follow-up biopsies. The median size of liver biopsies was 1.7 (range, 0.1-3) cm (Table 3).

Table 3 Liver biopsies between 1996 and 2006.
Number of successful liver biopsiesDiagnosis pre-biopsyHistoryAbnormal liver testsViral serologyAutoimmune/ImmunoglobulinsImagingOthersFinal Diagnosis
24Abnormal liver testsNon-specific Abdominal pains in 2YNSMA in 1 IgG in 1Normal/Echogenicn/aSimple steatosis: 12 NASH: 4 Autoimmune(including overlap): 2 Drug-related: 2 Microhamartomas: 1(laparoscopy) Non-specific: 2 Venous congestion: 1
6NAFLDMetabolic features presentYNIgA elevated in 2Echogenic 3n/aNASH: 1 Simple steatosis: 4 Normal: 1
3AlcoholStrong alcohol historyYNElevated IgG in 1 Autoimmune normalNormal 2 Ascites 1n/aALD: 1 (staging) ALD: 1 (diagnosis; transjugular) AIH: 1
6Iron overloadNY in 2NNEchogenic 3Elevated Ferritin in allC282Y/C282Y: 4 C282Y/H63D: 1 NAFLD (simple steatosis): 1
2Alcohol/Iron overload?Strong alcohol historyYNElevated IgAEchogenic 2Elevated Ferritin in 2C282Y/H63D + alcohol features: 2
8Liver lesions on imagingNY in 2NNMultiple lesions noted on US/CTn/aLung primary: 3 GIST: 1 GI tract: 2 Pancreas: 1 NASH: 1
9Hepatitis CYYPCR positiveNNormaln/aHepatitis C (staging) Genotype 1:6 Genotype 3:3
1Hepatitis BYNormalYNNormaln/aHepatitis B (staging)
1PBCNYNElevated IgM AMA: 1: 640Normaln/aPBC
8AIHNYNAIH: ANA + SMA in 3 Isolated SMA in 1 LKM + AMA in 1 Non-specific: Isolated SMA in 2 ANA only in 1Normal (7); Splenomegaly in 1n/aAIH: 3 (staging)(transjugular in 1) AIH: 1 (diagnosis) Possible AIH/PBC overlap: 1 Non-specific: 3
2Drug inducedYYNPolyclonal increase in IgNormaln/aDrug-cholestasis: 1 NAFLD(simple steatosis): 1
3MiscellaneousYY in PUONNNormaln/aPUO: 1 Methotrexate: 2(staging)

Liver biopsy findings: One-third of the biopsies were performed for undiagnosed elevation in the liver function tests and 12% were for staging of hepatitis C infection. Out of 59 USS-guided biopsies, 8 were performed in patients with focal lesions seen on abdominal imaging. Seven out of eight patients were found to have metastatic lesions while one patient had macrovesicular steatosis.

Changes in indications and/or findings over two decades

Between 1996 and 2006, 26% of patients were diagnosed with non-alcoholic fatty liver disease (NAFLD) (including non-alcoholic steatohepatitis), compared with 16.7% between 1986 and 1995. In the last ten years, targeted biopsies were also more common (11%; Table 3) but only one patient underwent biopsy for PBC.

Usefulness of liver biopsy

Diagnosis: In patients with elevated liver function tests but non-specific liver screen, liver biopsy confirmed the diagnoses in 25 out of 27 patients. It provided histological confirmation of metastases in 7 patients and was useful in confirming the overlap syndrome (autoimmune hepatitis/PBC) in 3 patients. Non-specific features were seen in 5 patients (5%).

Staging disease and treatment: Biopsy findings were used to stage autoimmune hepatitis, haemochromatosis, hepatitis B, hepatitis C, alcoholic liver disease and NAFLD. Those with moderate to severe fibrosis and cirrhosis at liver histology were placed on six-monthly hepatocellular carcinoma USS screening programme and had an upper gastrointestinal endoscopy to assess the presence and size of varices. Six patients with NASH were followed on a regimen of exercise and dietary changes, with tight glycaemic and blood pressure control. Nine patients with hepatitis C infections were treated with pegylated interferon and ribavarin.

Complications: Five patients experienced severe pain, requiring hospital admission and treatment with opiates. One patient developed a sub-capsular haematoma (blind biopsy); one patient developed pneumothorax (blind biopsy) that was managed conservatively; and another patient had an intra-abdominal bleed during TJB, requiring admission to the intensive care unit. There was no biopsy-related mortality.

DISCUSSION

In the present study, we observed an increasing number of liver biopsies being performed for elevated liver function tests. NAFLD was the most common diagnosis (70%) in these patients. When all the biopsies were taken in account, NAFLD accounted for nearly 30% of biopsies in our study population. These findings are consistent with the results of previous studies[12-14], and likely reflect that an increasing proportion of our population suffers from obesity[15-18] and non-insulin dependent diabetes mellitus[19,20]. Although the diagnosis of NAFLD can often be made clinically in patients with a combination of elevated liver tests, negative liver screen, 'bright' liver on abdominal USS and the presence of metabolic risk factors such as hypertension, non-insulin dependent diabetes mellitus, hyperlipidaemia and obesity[16,21,22], the distinction between simple steatosis and steatohepatitis can only be made by liver biopsy[23,24]. This is important because simple steatosis is considered a benign condition, while steatohepatitis can progress to cirrhosis[25]. Aggressive control of metabolic risk factors has been shown to improve the liver function tests and liver histology[26-31]. Although it is not feasible to biopsy all patients with possible NAFLD, this should be considered in patients who are older (over 40 years), obese or have non-insulin dependent diabetes[18,32].

With improvements in chemo-radiotherapy regimens, many patients with metastatic diseases are offered neo-adjuvant and adjuvant therapy. Hepatic resection for colorectal metastases limited to the liver, has become the standard of care[33,34]. Imaging guided biopsy of liver lesions is being performed increasingly to confirm metastases and to determine the primary tumor. By contrast, a liver biopsy is no longer necessary to make a diagnosis of PBC. A persistently elevated E2AMA strongly suggests PBC, even in asymptomatic patients[35]. Moreover, Cox-regression analyses have shown that the main prognostic marker in PBC is serum bilirubin[36]; thus indicating that the presence of fibrosis or cirrhosis in PBC is of limited prognostic use.

Liver biopsies are currently recommended in patients with chronic hepatitis C before treatment to stage and grade the disease[37,38]. Six patients with genotype 1 disease and three with genotype 3 disease received combination treatment with pegylated interferon and ribavarin. Since over 75% of patients infected with genotype 3 hepatitis C have a sustained virologic response after six months of combination treatment with pegylated interferon and ribavarin[39]; a liver biopsy may be unnecessary in some of these patients. In the future, non-invasive fibrosis markers are likely to play a bigger role in staging liver disease. We found that in patients with isolated autoantibodies or complex clinical and laboratory features, a liver biopsy was able to confirm the disease processes. For example, in a patient with excessive alcohol consumption who also had elevated immunoglobulin levels, liver biopsy indicated a diagnosis of autoimmune hepatitis instead of alcoholic hepatitis.

Liver biopsies from five patients showed non-specific features (5%). It has been suggested that for evaluation of diffuse liver disease, a core of at least 1.5cm is required[40] as it provides at least 6 to 8 portal tracts for adequate histological assessment. Although the median biopsy size in the study was 1.5 cm, many samples were inadequate, with the smallest recorded size being 0.1 cm. Three of these patients had biopsy fragments measuring less than 1cm in size, which may account for the non-specific findings. Liver biopsies are generally not required in patients with acute hepatitis[1]. We however, found it helpful in three patients (Table 4).

Table 4 Liver biopsies for acute hepatitis.
Acute hepatitisPre-biopsy diagnosisFinal diagnosis
1Cause unknownLikely drug-induced; prednisolone started
2Cause unknownMild steatohepatitis
3Pyrexia of unknown originTuberculosis excluded
4Cause unknownNo specific features
5Cause unknownMicrohamartomas with cholestatic hepatitis

The most common complication of liver biopsy is abdominal discomfort. Hospitalization is needed in up to 3% of patients for pain and hypotension[41,42], but major complications are rare[43]. At our centre, five patients (5.6% of patients, 5.2% of biopsies) were admitted for severe pain while another patient developed clinically significant intraperitoneal bleed after a TJB and required intensive care treatment. Consistent with published reports[44,45], we found a trend towards greater technical failures and complications with the 'blind' biopsy technique. Three out of four patients who needed a second liver biopsy had their initial biopsies performed 'blind'; two other patients, one with a pneumothorax and the second with sub-capsular haematoma also had 'blind' biopsies. In the last decade, nearly 78% of all biopsies in our unit were USS-guided. This increase is likely to be related to the increasing availability and safety of USS-guided liver biopsy[46,47].

Although our study population was small, it is reflective of the current DGH practice in the UK. Post-liver transplant, protocol liver biopsies are performed at the tertiary transplant units, hence the absence such data in the present study.

In conclusion, our findings confirm that liver biopsies in the DGH are safe and useful in the evaluation and staging of liver diseases. USS-guided rather than 'blind' liver biopsies are likely to be the preferred technique by patients and clinicians. NAFLD rather than PBC or viral hepatitis, will increasingly constitute the majority share of the liver biopsy workload.

COMMENTS
Background

Liver biopsy is a widely used tool in the investigation of liver diseases. However, it is an invasive procedure and studies have shown that less than one-third of the biopsies actually alter the management of patients. A liver biopsy should therefore only be performed in those patients who would benefit from such a procedure. Over the last two decades, changes in the socio-economic status and life-style have led to alterations in disease profiles. There is an increasing burden of obesity, type II diabetes mellitus and non-alcoholic steatohepatitis. Non-alcoholic steatohepatitis is now one of the most common causes of chronic liver disease and indications for liver transplantation in the USA. Concurrently, there have been rapid improvements in diagnostic and treatment options for patients with liver disease. With such changes, we expect that indications for liver biopsy will also evolve over time.

Research frontiers

Between 1986 and 1996, liver biopsies were performed mainly in patients with primary biliary cirrhosis as part of the staging process. With the development of reliable immunological markers designed to confirm the diagnosis, and prognostic markers to predict outcome of primary biliary cirrhosis, liver biopsy is no longer necessary. Between 1996 and 2006, the majority of biopsies (> 40%) were performed for raised liver function tests and hepatitis C staging. Non-alcoholic fatty liver disease was also found to be more common. In the present study, only 5% of biopsies showed non-specific features and were therefore unhelpful in patient management. The rest of the biopsies confirmed the diagnoses of the primary liver disease or the presence of metastasis. Patients with end-stage liver disease were placed on regular surveillance and those with treatable diseases were managed according to the treatment protocols. The complication rates after a liver biopsy in a district general hospital were found to be similar to the published rates. Between 5% and 6% of patients were admitted for severe pain. There was a trend towards increasing technical failures and complications with blind liver biopsy. In the last decade, ultrasound-guided biopsies were obtained more frequently than blind biopsies.

Innovations and breakthroughs

This study confirms that a liver biopsy is safe and useful in evaluating and staging of liver disease, even in district general hospitals. The risks from a biopsy remains small, but ultrasound-guided biopsies should be the preferred technique. In the future, non-alcoholic fatty liver disease will account for the vast share of the biopsy workload.

Applications

Useful for practicing clinicians in smaller hospitals as it confirms the safety and utility of a liver biopsy. Ultrasound-guidance may be safer. Non-alcoholic fatty liver disease is increasingly common.

Peer review

This is a very nice review that describes the historical changes in liver biopsy methodology over the past 20 years. The data presented is clear and concise and has been described clearly in the text.

Footnotes

S- Editor Zhu LH L- Editor Anand BS E- Editor Yin DH

References
1.  Grant A, Neuberger J. Guidelines on the use of liver biopsy in clinical practice. British Society of Gastroenterology. Gut. 1999;45 Suppl 4:IV1-IV11.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 158]  [Cited by in F6Publishing: 212]  [Article Influence: 8.5]  [Reference Citation Analysis (0)]
2.  Sherlock S, Dooley J. Chapter 3: Biopsy of the Liver. Diseases of the liver and biliary system. 11th ed. Oxford, UK: Blackwell Science Ltd 2002; 37-44.  [PubMed]  [DOI]  [Cited in This Article: ]
3.  Sorbi D, McGill DB, Thistle JL, Therneau TM, Henry J, Lindor KD. An assessment of the role of liver biopsies in asymptomatic patients with chronic liver test abnormalities. Am J Gastroenterol. 2000;95:3206-3210.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 79]  [Cited by in F6Publishing: 83]  [Article Influence: 3.5]  [Reference Citation Analysis (0)]
4.  Office for National Statistics. Obesity among adults: by sex and NS-SeC, 2001: Social Trends 34.  Available from: http: //www.statistics.gov.uk.  [PubMed]  [DOI]  [Cited in This Article: ]
5.  Livingstone MB. Childhood obesity in Europe: a growing concern. Public Health Nutr. 2001;4:109-116.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 83]  [Cited by in F6Publishing: 90]  [Article Influence: 3.9]  [Reference Citation Analysis (0)]
6.  Lipscombe LL, Hux JE. Trends in diabetes prevalence, incidence, and mortality in Ontario, Canada 1995-2005: a population-based study. Lancet. 2007;369:750-756.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 427]  [Cited by in F6Publishing: 440]  [Article Influence: 25.9]  [Reference Citation Analysis (0)]
7.  Ehtisham S, Barrett TG. The emergence of type 2 diabetes in childhood. Ann Clin Biochem. 2004;41:10-16.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 34]  [Cited by in F6Publishing: 35]  [Article Influence: 1.8]  [Reference Citation Analysis (0)]
8.  Marchesini G, Bugianesi E, Forlani G, Cerrelli F, Lenzi M, Manini R, Natale S, Vanni E, Villanova N, Melchionda N. Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome. Hepatology. 2003;37:917-923.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1907]  [Cited by in F6Publishing: 1870]  [Article Influence: 89.0]  [Reference Citation Analysis (0)]
9.  Clark JM, Diehl AM. Nonalcoholic fatty liver disease: an underrecognized cause of cryptogenic cirrhosis. JAMA. 2003;289:3000-3004.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 282]  [Cited by in F6Publishing: 270]  [Article Influence: 12.9]  [Reference Citation Analysis (0)]
10.  Gilmore IT, Burroughs A, Murray-Lyon IM, Williams R, Jenkins D, Hopkins A. Indications, methods, and outcomes of percutaneous liver biopsy in England and Wales: an audit by the British Society of Gastroenterology and the Royal College of Physicians of London. Gut. 1995;36:437-441.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 278]  [Cited by in F6Publishing: 269]  [Article Influence: 9.3]  [Reference Citation Analysis (0)]
11.  Dixon AK, Nunez DJ, Bradley JR, Seymour CA. Failure of percutaneous liver biopsy: anatomical variation. Lancet. 1987;2:437-439.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 4]  [Cited by in F6Publishing: 4]  [Article Influence: 0.1]  [Reference Citation Analysis (0)]
12.  Mathiesen UL, Franzén LE, Frydén A, Foberg U, Bodemar G. The clinical significance of slightly to moderately increased liver transaminase values in asymptomatic patients. Scand J Gastroenterol. 1999;34:85-91.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 86]  [Cited by in F6Publishing: 77]  [Article Influence: 3.1]  [Reference Citation Analysis (0)]
13.  Daniel S, Ben-Menachem T, Vasudevan G, Ma CK, Blumenkehl M. Prospective evaluation of unexplained chronic liver transaminase abnormalities in asymptomatic and symptomatic patients. Am J Gastroenterol. 1999;94:3010-3014.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 231]  [Cited by in F6Publishing: 244]  [Article Influence: 9.8]  [Reference Citation Analysis (0)]
14.  Skelly MM, James PD, Ryder SD. Findings on liver biopsy to investigate abnormal liver function tests in the absence of diagnostic serology. J Hepatol. 2001;35:195-199.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 219]  [Cited by in F6Publishing: 190]  [Article Influence: 8.3]  [Reference Citation Analysis (0)]
15.  Ludwig J, Viggiano TR, McGill DB, Oh BJ. Nonalcoholic steatohepatitis: Mayo Clinic experiences with a hitherto unnamed disease. Mayo Clin Proc. 1980;55:434-438.  [PubMed]  [DOI]  [Cited in This Article: ]
16.  Powell EE, Cooksley WG, Hanson R, Searle J, Halliday JW, Powell LW. The natural history of nonalcoholic steatohepatitis: a follow-up study of forty-two patients for up to 21 years. Hepatology. 1990;11:74-80.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1029]  [Cited by in F6Publishing: 966]  [Article Influence: 28.4]  [Reference Citation Analysis (0)]
17.  Matteoni CA, Younossi ZM, Gramlich T, Boparai N, Liu YC, McCullough AJ. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology. 1999;116:1413-1419.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2357]  [Cited by in F6Publishing: 2269]  [Article Influence: 90.8]  [Reference Citation Analysis (0)]
18.  Angulo P, Keach JC, Batts KP, Lindor KD. Independent predictors of liver fibrosis in patients with nonalcoholic steatohepatitis. Hepatology. 1999;30:1356-1362.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1099]  [Cited by in F6Publishing: 1061]  [Article Influence: 42.4]  [Reference Citation Analysis (1)]
19.  Creutzfeldt W, Frerichs H, Sickinger K. Liver diseases and diabetes mellitus. Prog Liver Dis. 1970;3:371-407.  [PubMed]  [DOI]  [Cited in This Article: ]
20.  de Marco R, Locatelli F, Zoppini G, Verlato G, Bonora E, Muggeo M. Cause-specific mortality in type 2 diabetes. The Verona Diabetes Study. Diabetes Care. 1999;22:756-761.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 284]  [Cited by in F6Publishing: 263]  [Article Influence: 10.5]  [Reference Citation Analysis (0)]
21.  Chitturi S, Farrell GC. Etiopathogenesis of nonalcoholic steatohepatitis. Semin Liver Dis. 2001;21:27-41.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 460]  [Cited by in F6Publishing: 441]  [Article Influence: 19.2]  [Reference Citation Analysis (1)]
22.  Bacon BR, Farahvash MJ, Janney CG, Neuschwander-Tetri BA. Nonalcoholic steatohepatitis: an expanded clinical entity. Gastroenterology. 1994;107:1103-1109.  [PubMed]  [DOI]  [Cited in This Article: ]
23.  Bianchi L. Liver biopsy in elevated liver functions tests? An old question revisited. J Hepatol. 2001;35:290-294.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 32]  [Cited by in F6Publishing: 36]  [Article Influence: 1.6]  [Reference Citation Analysis (0)]
24.  Saadeh S, Younossi ZM, Remer EM, Gramlich T, Ong JP, Hurley M, Mullen KD, Cooper JN, Sheridan MJ. The utility of radiological imaging in nonalcoholic fatty liver disease. Gastroenterology. 2002;123:745-750.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1368]  [Cited by in F6Publishing: 1391]  [Article Influence: 63.2]  [Reference Citation Analysis (0)]
25.  Caldwell SH, Hylton AI. The clinical outcome of NAFLD including cryptogenic cirrhosis. Fatty Liver Disease: NASH and Related Disorders. Oxford, UK: Blackwell Publishing Ltd 2005; 168-180.  [PubMed]  [DOI]  [Cited in This Article: ]
26.  Akyüz F, Demir K, Ozdil S, Aksoy N, Poturoğlu S, Ibrişim D, Kaymakoğlu S, Beşişik F, Boztaş G, Cakaloğlu Y. The effects of rosiglitazone, metformin, and diet with exercise in nonalcoholic fatty liver disease. Dig Dis Sci. 2007;52:2359-2367.  [PubMed]  [DOI]  [Cited in This Article: ]
27.  Yamamoto M, Iwasa M, Iwata K, Kaito M, Sugimoto R, Urawa N, Mifuji R, Konishi M, Kobayashi Y, Adachi Y. Restriction of dietary calories, fat and iron improves non-alcoholic fatty liver disease. J Gastroenterol Hepatol. 2007;22:498-503.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 49]  [Cited by in F6Publishing: 46]  [Article Influence: 2.7]  [Reference Citation Analysis (0)]
28.  Portincasa P, Grattagliano I, Palmieri VO, Palasciano G. Current pharmacological treatment of nonalcoholic fatty liver. Curr Med Chem. 2006;13:2889-2900.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 36]  [Cited by in F6Publishing: 39]  [Article Influence: 2.2]  [Reference Citation Analysis (0)]
29.  Lavoie JM, Gauthier MS. Regulation of fat metabolism in the liver: link to non-alcoholic hepatic steatosis and impact of physical exercise. Cell Mol Life Sci. 2006;63:1393-1409.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 102]  [Cited by in F6Publishing: 92]  [Article Influence: 5.1]  [Reference Citation Analysis (0)]
30.  Ekstedt M, Franzén LE, Mathiesen UL, Holmqvist M, Bodemar G, Kechagias S. Statins in non-alcoholic fatty liver disease and chronically elevated liver enzymes: a histopathological follow-up study. J Hepatol. 2007;47:135-141.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 191]  [Cited by in F6Publishing: 187]  [Article Influence: 11.0]  [Reference Citation Analysis (0)]
31.  Belfort R, Harrison SA, Brown K, Darland C, Finch J, Hardies J, Balas B, Gastaldelli A, Tio F, Pulcini J. A placebo-controlled trial of pioglitazone in subjects with nonalcoholic steatohepatitis. N Engl J Med. 2006;355:2297-2307.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1307]  [Cited by in F6Publishing: 1264]  [Article Influence: 70.2]  [Reference Citation Analysis (0)]
32.  Ratziu V, Giral P, Charlotte F, Bruckert E, Thibault V, Theodorou I, Khalil L, Turpin G, Opolon P, Poynard T. Liver fibrosis in overweight patients. Gastroenterology. 2000;118:1117-1123.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 664]  [Cited by in F6Publishing: 678]  [Article Influence: 28.3]  [Reference Citation Analysis (0)]
33.  Welsh FK, Tilney HS, Tekkis PP, John TG, Rees M. Safe liver resection following chemotherapy for colorectal metastases is a matter of timing. Br J Cancer. 2007;96:1037-1042.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 160]  [Cited by in F6Publishing: 159]  [Article Influence: 9.4]  [Reference Citation Analysis (0)]
34.  Cummings LC, Payes JD, Cooper GS. Survival after hepatic resection in metastatic colorectal cancer: a population-based study. Cancer. 2007;109:718-726.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 240]  [Cited by in F6Publishing: 228]  [Article Influence: 13.4]  [Reference Citation Analysis (0)]
35.  Metcalf JV, Mitchison HC, Palmer JM, Jones DE, Bassendine MF, James OF. Natural history of early primary biliary cirrhosis. Lancet. 1996;348:1399-1402.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 302]  [Cited by in F6Publishing: 266]  [Article Influence: 9.5]  [Reference Citation Analysis (0)]
36.  Neuberger J. Primary biliary cirrhosis. Comprehensive Clinical Hepatology. Mosby, London: Harcourt Publishers Limited 2000; 17.1-17.13.  [PubMed]  [DOI]  [Cited in This Article: ]
37.  National Institute for Health and Clinical Excellence. Peginterferon alfa and ribavirin for the treatment of mild chronic hepatitis C. Technology appraisal 2006 (106).  Available from: http: //www.nice.org.uk/TA106.  [PubMed]  [DOI]  [Cited in This Article: ]
38.  National Institute for Health and Clinical Excellence. Interferon alfa (pegylated and non-pegylated) and ribavirin for the treatment of chronic hepatitis C. Technology appraisal 2004 (75).  Available from: http: //www.nice.org.uk/TA75.  [PubMed]  [DOI]  [Cited in This Article: ]
39.  Brandão C, Barone A, Carrilho F, Silva A, Patelli M, Caramori C, Focaccia R, Pereira L, Pedroso M, Tatsch F. The results of a randomized trial looking at 24 weeks vs 48 weeks of treatment with peginterferon alpha-2a (40 kDa) and ribavirin combination therapy in patients with chronic hepatitis C genotype 1. J Viral Hepat. 2006;13:552-559.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 11]  [Cited by in F6Publishing: 12]  [Article Influence: 0.7]  [Reference Citation Analysis (0)]
40.  Bravo AA, Sheth SG, Chopra S. Liver biopsy. N Engl J Med. 2001;344:495-500.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1678]  [Cited by in F6Publishing: 1683]  [Article Influence: 73.2]  [Reference Citation Analysis (0)]
41.  Garcia-Tsao G, Boyer JL. Outpatient liver biopsy: how safe is it? Ann Intern Med. 1993;118:150-153.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 98]  [Cited by in F6Publishing: 104]  [Article Influence: 3.4]  [Reference Citation Analysis (0)]
42.  Janes CH, Lindor KD. Outcome of patients hospitalized for complications after outpatient liver biopsy. Ann Intern Med. 1993;118:96-98.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 196]  [Cited by in F6Publishing: 207]  [Article Influence: 6.7]  [Reference Citation Analysis (0)]
43.  Piccinino F, Sagnelli E, Pasquale G, Giusti G. Complications following percutaneous liver biopsy. A multicentre retrospective study on 68,276 biopsies. J Hepatol. 1986;2:165-173.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 850]  [Cited by in F6Publishing: 783]  [Article Influence: 20.6]  [Reference Citation Analysis (0)]
44.  Farrell RJ, Smiddy PF, Pilkington RM, Tobin AA, Mooney EE, Temperley IJ, McDonald GS, Bowmer HA, Wilson GF, Kelleher D. Guided versus blind liver biopsy for chronic hepatitis C: clinical benefits and costs. J Hepatol. 1999;30:580-587.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 82]  [Cited by in F6Publishing: 88]  [Article Influence: 3.5]  [Reference Citation Analysis (0)]
45.  Nobili V, Comparcola D, Sartorelli MR, Natali G, Monti L, Falappa P, Marcellini M. Blind and ultrasound-guided percutaneous liver biopsy in children. Pediatr Radiol. 2003;33:772-775.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 44]  [Cited by in F6Publishing: 47]  [Article Influence: 2.2]  [Reference Citation Analysis (0)]
46.  Vautier G, Scott B, Jenkins D. Liver biopsy: blind or guided? BMJ. 1994;309:1455-1456.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 41]  [Article Influence: 1.4]  [Reference Citation Analysis (0)]
47.  Caturelli E, Giacobbe A, Facciorusso D, Bisceglia M, Villani MR, Siena DA, Fusilli S, Squillante MM, Andriulli A. Percutaneous biopsy in diffuse liver disease: increasing diagnostic yield and decreasing complication rate by routine ultrasound assessment of puncture site. Am J Gastroenterol. 1996;91:1318-1321.  [PubMed]  [DOI]  [Cited in This Article: ]