The role of liver and spleen elastography in advanced chronic liver disease.

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD). In the last decade, many non-invasive tests, such us liver and spleen elastography, have been proposed and validated for the identification of patients with clinically significant portal hypertension (CSPH) and its complications, mainly hepatic decompensation and liver-related morbidity and mortality. Moreover, elastography accurately stratifies for the risk of HCC development, HCC recurrence and decompensation after liver surgery. Recent studies suggest a role of SSM in monitoring response to treatments and interventions in ACLD, such as viral eradication, non-selective beta-blockers and transjugular intrahepatic portosystemic shunt placement. However, one of the most indications to perform elastography in ACLD still remains the screening for esophageal varices. In fact, according to the Baveno VI consensus, liver stiffness measurement (LSM) <20 kPa and platelet count >150,000/mm can safely identify patients at low risk of varices requiring treatment (VNT) and could therefore avoid invasive upper invasive endoscopy; LSM>20-25 kPa can accurately rule-in CSPH in patients with viral etiology. Spleen stiffness measurement (SSM) is a direct surrogate of portal hypertension and has been demonstrated more accurate in predicting portal hypertension severity and VNT. A combined model including Baveno VI Criteria and SSM (≤46 kPa) can significantly increase the number of spared endoscopies (>40-50%), maintaining a low (<5%) of missed VNT.