Diagnosis of liver fibrosis and cirrhosis using liver stiffness measurement: comparison between M and XL probe of FibroScan®.

Background & Aims: Unreliable results of liver stiffness measurement are obtained in 16% of cases and are independently associated with body mass index (BMI) greater than 30 kg/m(2). A new FibroScan® probe (XL probe) was designed specifically for obese patients. The aim of this study was to evaluate the accuracy of liver stiffness measurement using M and XL probes of Fibroscan® for the diagnosis of fibrosis and cirrhosis in a large cohort of patients.
Methods: Consecutive patients undergoing liver biopsies for chronic liver disease were prospectively recruited. Liver stiffness measurement was performed within 1 week before liver biopsy using both M and XL probes of FibroScan®.
Results: A total of 286 patients were evaluated. A reliable liver stiffness measurement using M probe was obtained in 79.7% of cases. In the other 21.3%, liver stiffness measurement using XL probe was obtained in 56.9% of patients. A strong correlation was found between M and XL values, regardless of BMI. In all groups, median liver stiffness measurement using the XL probe was significantly lower than liver stiffness measurement using the M probe. By multivariate analysis, unsuccessful liver stiffness examination with M probe was independently associated with age >50 years and BMI >30 kg/m(2). By univariate analysis, only BMI >30 kg/m(2) was associated with unsuccessful liver stiffness measurement with XL probe. No significant difference was observed between the M and XL probes for the diagnosis of liver fibrosis.
Conclusions: Liver stiffness measurement with either M or XL probe is possible in 91.2% of patients with comparable diagnostic accuracy. In clinical practice, the M probe could be used as first step for liver stiffness measurement. In case of no valid shot or unreliable measurement, the XL probe could be used. This result could be useful for the assessment of liver fibrosis in NAFLD and/or obese patients.
(Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)