Global Coagulation Assessment in Portal Vein Thrombosis and Budd-Chiari Syndrome

Portal vein thrombosis is defined as partial or complete occlusion of the portal vein lumen by the blood clot or its replacement by multiple collateral vessels with the hepato-petal flow, known as 'portal cavernoma'. \[1,2\] Based on the published literature, 15-25% of patients with cirrhosis have portal vein thrombosis (PVT) \[3\], and 35-50% of patients with hepatocellular carcinoma (HCC) have malignant PVT \[4\] compared to 1-3.8 per 100,000 patients in the general population. \[5\] The reported cumulative incidence of PVT in patients of Child-Pugh A and B is 4.6% and 10.7% at 1 and 5 years respectively with higher incidence among those with decompensated disease or with an underlying hypercoagulable disorder. \[6\]. Similarly, the prevalence of PVT in compensated cirrhosis is around 1% which increases to 8 - 25% in liver transplant (LT) candidates and 40% in patients with hepatocellular carcinoma (HCC) \[7,8\]. Based on the published literature 7-9 % of all chronic liver disease patients have hepatic vein outflow tract obstruction (HVOTO) in the Indian population. \[9\] HVOTO is defined as obstruction to hepatic venous outflow at any site from the right atrium inlet to the small hepatic venules. The Budd-Chiari syndrome (BCS) results from occlusion of one or more hepatic veins (HV) and/or the inferior vena cava (IVC). In the West, the most common cause is HV occlusion by thrombosis. More recent Indian studies have however shown that isolated HV and combined IVC+HV obstruction are now more common. \[10\] In the post COVID-19 era, there has been great interest in the prothrombotic states associated with the SARS-Cov-2 virus infection, and the adverse effects of some vaccines. \[11\] With the availability of better molecular tests for hypercoagulable states, use of global coagulation tests (GCT) like rotational thromboelastometry (ROTEM), thromboelastography (TEG) and Sonoclot, use of therapeutic procedures like Transjugular intrahepatic portosystemic shunt (TIPS)