Feasibility and Efficacy of Transient Elastography using the XL probe to diagnose liver fibrosis and cirrhosis

Abstract

Background:Transient elastography (TE) has been validated as an effective noninvasive tool for the assessment of liver fibrosis. The XL probe is a new probe that was initially designed for use in patients with obesity. A meta-analysis was performed to assess the feasibility and efficacy of TE using the XL probe.Methods:In September 2016, we systematically searched the PubMed and Science Direct search engines. The feasibility of TE was evaluated based on the failure rate and the results of the unreliable liver stiffness measurement (LSM). The efficacy of TE was measured using sensitivity, specificity, and summary receiver-operating characteristic as measures/indices assessed in different stages of fibrosis. Heterogeneity was measured using the chi-squared test and the Q-statistic. We used the 95% confidence interval (95% CI) as an effect measure.Results:We included 8 studies in the meta-analysis. When the XL was compared to the M probe, the former showed a lower risk of failure rate [relative risk (RR) 0.24, 95% CI 0.14–0.38]. In patients with a body mass index ≥30 kg/m2, the XL probe showed a statistically significantly lower risk of failure rate (RR 0.16, 95% CI 0.08–0.32) but no significant improvement (RR 0.76, 95% CI 0.50–1.16) in the unreliable LSM result. In patients showing liver fibrosis stage ≥F2, the XL probe showed a sensitivity of 0.56 (95% CI 0.39–0.72), specificity of 0.71 (95% CI 0.61–0.79), and an area under the curve (AUC) of 0.71. The results observed in patients with liver fibrosis stage F4 were more promising with a sensitivity of 0.84 (95% CI 0.76–0.90), specificity of 0.78 (95% CI 0.70–0.84), and an AUC of 0.88.Conclusion:TE using the XL probe demonstrates significant diagnostic utility in patients with liver fibrosis and is likely to be more reliable than the M probe in patients with obesity. Large prospective multicenter studies are, however, necessary to establish the new cut-off values to be used for the XL probe in patients with obesity.

A review of the use of transient elastography in the assessment of fibrosis and steatosis in the post–liver transplant patient

“…The development of the XL probe has improved the usefulness of TE in this population; however, limitations remain. In a meta‐analysis of studies comparing the use of the XL probe to the M probe, the former was found to have lower rates of failure in patients with a BMI ≥30 kg/m 2 (RR 0.16, 95% CI 0.08‐0.32, P < .00001) . However, the rates of unreliable measurements were not significantly different between the two probes (RR 0.63, 95% CI, 0.30‐1.32, P = .22).…”

Ultrasound-guided transient elastography and two-dimensional shear wave elastography for assessment of liver fibrosis: emphasis on technical success and reliable measurements

“…LS measurements were made with TE (Fibroscan, EchoSens, Paris, France) using a LOGIQ S8 US scanner in two sessions. The standard M probe was used for all participants unless the use of an XL probe was recommended by the scanner [ 21 ].…”

A prospective 5-year study on the use of transient elastography to monitor the improvement of non-alcoholic fatty liver disease following bariatric surgery

“…Earlier studies suggested that the failure rate of TE was lower in obese patients with the use of XL probe 45 . A study by Wong et al suggested that the median LSM obtained by M and XL probes were nearly identical at each fibrosis stage when M probe was used in patients with BMI < 30 kg/m 2 and XL probe was used in those with BMI ≥ 30 kg/m 2 46 .…”