Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2021; 27(23): 3290-3302
Published online Jun 21, 2021. doi: 10.3748/wjg.v27.i23.3290
Viscoelastic tests in liver disease: where do we stand now?
Alina Buliarca, Adelina Horhat, Tudor Mocan, Rares Craciun, Bogdan Procopet, Zeno Sparchez
Alina Buliarca, Adelina Horhat, Tudor Mocan, Rares Craciun, Bogdan Procopet, Zeno Sparchez, The Third Medical Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, Institute for Gastroenterology and Hepatology “Prof. Dr. O. Fodor”, Cluj-Napoca 400162, Romania
Author contributions: Buliarca A, Horhat A, Mocan T, Craciun R and Sparchez Z collected the data, analyzed the data; Buliarca A and Procopet B drafted the manuscript; Procopet B revised the manuscript for important intellectual content; all authors have read and approved the final version to be published.
Conflict-of-interest statement: The authors have no other disclosures.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Tudor Mocan, MD, Research Scientist, The Third Medical Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, Institute for Gastroenterology and Hepatology “Prof. Dr. O. Fodor”, Croitorilor st. 19-21, Cluj-Napoca 400162, Romania.
Received: January 28, 2021
Peer-review started: January 28, 2021
First decision: March 14, 2021
Revised: March 17, 2021
Accepted: May 20, 2021
Article in press: May 20, 2021
Published online: June 21, 2021

Hemostasis is a complex physiological process based on the balance between pro-coagulant and anticoagulant systems to avoid pathological bleeding or thrombosis. The changes in standard coagulation tests in liver disease were assumed to reflect an acquired bleeding disorder, and cirrhotic patients were considered naturally anticoagulated. In the light of the new evidence, the theory of rebalanced hemostasis replaced the old concept. According to this model, the hemostatic alteration leads to a unique balance between pro-coagulant, anticoagulant, and fibrinolytic systems. But the balance is fragile and may prone to bleeding or thrombosis depending on various risk factors. The standard coagulation tests [INR (international normalized ratio), platelet count and fibrinogen] only explore parts of the hemostasis, not offering an entire image of the process. Rotational thromboelastometry (ROTEM) and thromboelastography (TEG) are both point of care viscoelastic tests (VET) that provide real-time and dynamic information about the entire hemostasis process, including clot initiation (thrombin generation), clot kinetics, clot strength, and clot stability (lysis). Despite prolonged PT/INR (international normalized ratio of prothrombin time) and low platelet counts, VET is within the normal range in many patients with both acute and chronic liver disease. However, bleeding remains the dominant clinical issue in patients with liver diseases, especially when invasive interventions are required. VET has been shown to asses more appropriately the risk of bleeding than conventional laboratory tests, leading to decrial use of blood products transfusion. Inappropriate clotting is common but often subtle and may be challenging to predict even with the help of VET. Although VET has shown its benefit, more studies are needed to establish cut-off values for TEG and ROTEM in these populations and standardization of transfusion guidelines before invasive interventions in cirrhotic patients/orthotopic liver transplantation.

Keywords: Liver diseases, Viscoelastic tests, Portal vein thrombosis, Acute-on-chronic liver failure, Bleeding risk, Invasive procedures

Core Tip: Despite having specific alterations in all hemostasis phases and, thus, considered naturally anticoagulated, cirrhotic patients have, in fact, balanced hemostasis. However, this balance may be disturbed by different factors, and the result may vary from devastating bleeding to massive thrombosis. Conventional laboratory tests failed to predict these events. Viscoelastic tests appear to offer a better, global view of hemostasis in these patients. They have been used to assess bleeding risk before invasive interventions and for a precocious use of blood product transfusions.