We have read the article entitled Usefulness of acoustic radiation force impulse and fibrotest in liver fibrosis assessment after liver transplant by Bignulin, et al. with interest.1 They deduced that acoustic elastic radiation force impulse (ARFI) and Fibrotest were handy tools to stage the severity of fibrosis in patients with liver transplant. We would like to thank the authors for their priceless contribution. However, we would like to report few concerns regarding this study from a methodological point of view.
First, it is stated in the present study that the measurements of ARFI were performed in the right liver lobe through the intercostal space in the supine position.1 Contrary to this research, Uslu, et al. demonstrated that subcostal approach to the liver parenchyma was significantly superior to intercostal approach for the evaluation of stiffness.2 If the ARFI measurements had been performed through the subcostal space, the pressure would have been transmitted better to liver parenchyma, and this would have given better results than intercostal approach in terms of determining the elasticity of the liver.
Second, the length of the biopsy material was not mentioned in present study. Bedossa, et al. demonstrated 40 mm long biopsy was considered an optimal specimen for accurate evaluation of liver fibrosis.3 Additionally, the median number of the pieces of portal tracts was 10 in present study. According to American Association of Study of Liver Disease guidelines, an adequate number of portal tracts has been proposed to be > 11.4 It would have been better, if the authors had been mentioned these constitute limitations in the study.
Third, Trovato, et al. demonstrated that ARFI and transient elastography of the spleen is correlated with Ishak fibrosis staging, and could be a possible additional tool for the diagnosis of liver fibrosis.5 It would have been relevant, if the authors had evaluated their patients according to spleen measurements of these techniques.
