Liver and spleen stiffness as assessed by vibration controlled transient elastography for diagnosing clinically significant portal hypertension in comparison with other elastography-based techniques in adults with chronic liver disease

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

      To assess the diagnostic accuracy of liver stiffness and spleen stiffness, as well as their combination, as measured by vibration-controlled transient elastography (VCTE) in the detection of clinically significant portal hypertension (CSPH) in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

        To compare the diagnostic accuracy of individual tests (liver and spleen stiffness by VCTE) directly and versus the combination of both tests (liver and spleen stiffness by VCTE considered positive when at least one test is positive) in detecting CSPH.

          To assess the diagnostic accuracy of liver stiffness and spleen stiffness, as well as their combination, as measured by other elastography techniques (two-dimensional shear wave elastography (2D-SWE), point shear wave elastography (pSWE), and magnetic resonance elastography (MRE)) in the detection of CSPH in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

            To compare the diagnostic accuracy of liver stiffness and spleen stiffness by VCTE with other techniques (2D-SWE, pSWE, MRE) in the detection of CSPH in adults with chronic liver disease.

          Secondary objectives

              To assess the diagnostic accuracy of liver stiffness and spleen stiffness, as well as their combination, as measured by VCTE in the detection of severe portal hypertension (SPH) in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

                To assess the diagnostic accuracy of liver stiffness and spleen stiffness, as well as their combination, as measured by the other elastography techniques (2D-SWE, pSWE, MRE) in the detection of SPH in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

                  To compare the diagnostic accuracy of liver stiffness and spleen stiffness by VCTE with other techniques (pSWE, 2D-SWE, MRE) in the detection of SPH in adults with chronic liver disease.

                    To investigate the following potential sources of heterogeneity in the results of liver stiffness and spleen stiffness, as well as their combination, as measured by VCTE in the detection of CSPH and SPH.

                          Different populations based on the chronic liver disease aetiology, in particular viral compared to non-viral aetiology: studies including more than 80% of participants with viral aetiology compared to those including less than 80% of participants with viral aetiology. We have chosen a threshold of 80%, as in North America and Europe the prevalence of chronic viral hepatitis is usually lower, whilst in Asia and Africa the prevalence is higher (Wong 2015).

                            Different prevalences of CSPH: studies with prevalence of CSPH > 50% compared to studies with prevalence of CSPH ≤ 50%. We have chosen a threshold of 50% according to a median prevalence of any size oesophageal varices in adults at the diagnosis of cirrhosis (Colli 2014a).

                              Different prevalences of SPH: studies with prevalence of SPH > 25% compared to studies with prevalence of SPH ≤ 25%. We have chosen a threshold of 25% according to a median prevalence of high-risk oesophageal varices in adults at the diagnosis of cirrhosis (Colli 2014a).

                                Different populations based on the chronic liver disease severity: studies including more than 75% of participants with cirrhosis (Child-Pugh class A) compared to studies including less than 75% of participants with cirrhosis (Child-Pugh class A). We have chosen a threshold of 75% according to a median prevalence of adults with cirrhosis in Child-Pugh class A of 74% in a large cohort study (D'Amico 2014).

                                  Type of probe used (liver, LSM@50Hz versus spleen, SSM@100Hz) for spleen stiffness measurement by VCTE.

                                    Type of probe used (M versus XL) when liver, LSM@50Hz probe is used for spleen stiffness measurement by VCTE.

                                      Number of unsuccessful or indeterminate results to obtain any LSM or SSM: studies with more than 20% compared to studies with less than 20% of unsuccessful or indeterminate results. We have chosen a threshold of 20%, as the test applicability estimated in a large series was 81% (Castéra 2010).

This is a protocol.