**7. Conclusion**

more precise diagnoses [52, 53]. The first embodiments of this technique required dedicated endoscopes to be used for evaluating cavitary structures accessible from both ends of the di‐

Recent advancements however were able to miniaturize the technology so the imaging mi‐ croprobe can be connected to 30,000 fiber-optic threads that enable point-to-point real-time detection at 12 frames/sec. The imaging device by itself measures less than 1.5 millimeters in diameter, thus allowing its use through 19G or tru-cut biopsy needles, or insertion by lapa‐ roscopy or NOTES [53]. This technology will allow in vivo, real-time imaging of liver histol‐ ogy, technically enhancing the capabilities of liver biopsy [54]. A few studies on animal models exist in the literature, detailing pCLE use for liver histological imaging [14, 55, 56]. The technique can be used for assessing the state of hepatocytes and the morphology of the liver tissue, or can be limited to the study of the exterior liver capsule, yielding interesting preliminary results in the setting of cirrhosis. Mennone et al reported interesting results re‐ garding a fibrotic pattern and collagen deposits in animal models with cirrhosis induced by bile duct ligation [14]. The technology shows promise and may someday allow for safer his‐ tological assessment of patients with chronic liver disease irrespective of its advancement,

either cirrhotic or having any extreme complications, such as HCC.

transaminase to platelets ratio index (ARPI) approaches.

rosis measurement obtained through biopsy [2].

**6.2. Non-invasive imaging and serum tests for the assessment of fibrosis**

Transient elastography (TE, Fibroscan® developed by Echosens, Paris, France) and Acoustic radiation force impulse (ARFI) are two ultrasound-based methods for quantifying liver fib‐ rosis without the need for histological assessment. Another approach is through serum markers of fibrosis quantification, processed in complex mathematical formulas which give a quantitative result for liver stiffness, such as the Fibrotest, Biopredictive and the aspartate

TE is a novel and rapid non-invasive examination which involves minimal patient discom‐ fort over a relatively low time period (one examination may take up to 5-10 minutes de‐ pending on the skeletal and adipose conformations of the patient). The device consists of a hand-held vibrating unit with an ultrasound transducer probe mounted on its axis, which generates medium amplitude vibrations at a low frequency, thus inducing an elastic shear wave in the underlying tissue. The hand-held probe is connected to a modified tower US machine which registers the result and through the on-screen software interface presents the user with an elastogram as a function of depth in time. The patient lies on his/her side and the probe is placed against the skin on the median clavicle line, directed towards the ana‐ tomical location of the liver, at a 90 degrees angle with the skin surface. Its results are pre‐ sented as kilo Pascals (kPa), units of applied force. A series of 10 measurements are mediated to present a final value of the liver stiffness, which is equivalent to an F-stage fib‐

ARFI is another technology that uses short-duration, high-intensity acoustic pulses which in turn exert mechanical excitation upon the tissues, generating local displacement resulting in shear waves. Their velocity can be assessed in a selected cylindrical area of interest of 0.5 cm

gestive tracts.

96 Liver Biopsy – Indications, Procedures, Results

Despite all its limitations and the advances in modern lesser invasive techniques, liver biop‐ sy remains the gold standard for evaluating a wide array of liver diseases.

The main concern when turning to tissue sampling through biopsy is the risk/benefit ra‐ tio, the decision ultimately belonging to the clinician involved. The risks may at times be higher than the implied diagnostic outcome, in which case other methods are preferred for the diagnosis.

Currently, it is recommended that all interpretations should be based on proper tissue blocks, with the correct technique applied. It is preferred that more than one pathologist with extensive experience in liver pathology should formulate the final histological diagno‐ sis. This is especially true for FLLs and liver malignancies, as benign features may at times overlap, making the diagnosis uncertain.

Modern imagistic techniques allow for precise non-invasive evaluation of liver fibrosis in the context of hepatitis; however, the correct methodology for interpreting these tests is yet to be established. Novel imagistic approaches may in time open new perspectives for liver biopsy, by providing in vivo, real time data on liver parenchymal features which would prove useful for accurate diagnosing of otherwise difficult to interpret pathologies.

[10] Kalambokis G, Manousou P, Vibhakorn S, et al. Transjugular liver biopsy - Indica‐ tions, adequacy, quality of specimens, and complications - A systematic review. J

Risks and Benefits of Liver Biopsy in Focal Liver Disease

http://dx.doi.org/10.5772/52620

99

[11] Cholongitas E, Senzolo M, Standish R, Marelli L, Quaglia A, Patch D, Dhillon AP, Burroughs AK. A systematic review of the quality of liver biopsy specimens. Am J

[12] Denzer U, Arnoldy A, Kanzler S, et al. Prospective randomized comparison of mini‐ laparoscopy and percutaneous liver biopsy: diagnosis of cirrhosis and complications.

[13] Steele K, Schweitzer MA, Lyn-Sue J, Kantsevoy SV. Flexible transgastricperitoneosco‐ py and liver biopsy: a feasibility study in human beings (with videos). Gastrointes‐

[14] Mennone A, Nathanson MH. Needle-based confocal laser endomicroscopy to assess

[15] Goessling W, Friedman FS (2006). Evaluation of the Liver Patient. In: The clinician's

[16] Rockey DC, Caldwell SH, Goodman ZD et al. Liver biopsy. Hepatology.

[17] Guido M, Rugge M. Liver biopsy sampling in chronic viral hepatitis. Semin Liver

[18] Colloredo G, Guido M, Sonzogni A et al. Impact of liver biopsy size on histological evaluation of chronic viral hepatitis: the smaller the sample, the milder the disease. J

[19] Regev A, Berho M, Jeffers LJ et al. Sampling error and intra-observer variation in liv‐ er biopsy in patients with chronic HCV infection. Am J Gastroenterol. 2002; 97, 2614–

[20] Siddique I, El-Naga HA, Madda JP et al. Sampling variability on percutaneous liver biopsy in patients with chronic hepatitis C virus infection. Scand J Gastroenterol.

[21] Knodell RG, Ishak KG, Black WC, et al. Formulation and application of a numerical scoring system for assessing histological activity in asymptomatic chronic active hep‐

[22] Ishak K, Baptista A, Bianchi L, et al. Histological grading and staging of chronic hep‐

[23] METAVIR Cooperative Study Group. Intraobserver and interobserver variations in liver biopsy interpretation in patients with chronic hepatitis C. Hepatology. 1994; 20,

guide to liver disease, K. Rajender Reddy (Ed.),. SLACK Inc. USA: 1–31.

liver histology in vivo. GastrointestEndosc. 2011;73:338-44.

Hepatol 2007;47:284-294.

ClinPathol 2006, 125:710-21.

tEndosc 2008;68:61-66.

2009;49:1017-44.

2618.

15–20.

Dis. 2004;24: 89–97.

2003; 38, 427–432.

Hepatol, 2003; 39, 239–244.

atitis. Hepatology 1981;1:431-435.

atitis. J Hepatol 1995;22:696-699.

J ClinGastroenterol 2007;41:103-110.
