Transient elastography: a meta-analysis of diagnostic accuracy in evaluation of portal hypertension in chronic liver disease

Objectives Transient elastography (TE), as a non-invasive method, has been studied for evaluation of portal hypertension in patients with chronic liver diseases (CLD) with variable results. We studied the performance of TE for detection of significant portal hypertension, oesophageal varices and large oesophageal varices using meta-analysis. Methods PubMed, the Cochrane Library, EMBASE and ISI web of Knowledge were searched. The studies published in English relating to the diagnostic value of TE for significant portal hypertension, oesophageal varices and large oesophageal varices in patients with CLD were collected. Results A total of 18 studies, which included 3644 patients were analysed. Summary sensitivity and specificity were 0.90 (95% confidence interval (CI), 0.810.95) and 0.79 (95% CI, 0.580.91) for significant portal hypertension, and 0.87 (95% CI, 0.800.92) and 0.53 (95% CI, 0.360.69) for oesophageal varices and 0.86 (95% CI, 0.710.94) and 0.59 (95% CI, 0.450.72) for large oesophageal varices respectively. The HSROCs were 0.93 for significant portal hypertension, 0.84 for oesophageal varices and 0.78 for large oesophageal varices respectively. TE was very informative with 81% probability of correctly detection significant portal hypertension following a positive measurement (over the threshold value) and lowering the probability of disease to as low as 11% when negative measurement (below the threshold value) when pre-test probability was 50% whereas, for oesophageal varices or large oesophageal varices, the probability of a correct diagnosis following a positive measurement did not exceeded 70%. Conclusions TE could be used as a good screening tool for significant portal hypertension, but only moderate diagnostic utility for the prediction of oesophageal varices or large oesophageal varices.