Table 1.

New classification of portal vein thrombosis

Site of portal vein thrombosis Type 1: Trunk only Type 2: Branch only; 2a, one branch; 2b, both branches Type 3: Trunk and branches

Degree of portal venous system occlusion O: Occlusive: no flow visible in portal vein lumen on imaging/Doppler study NO: Non-occlusive: flow visible in portal vein lumen through imaging/Doppler study

Duration and presentation R: Recent (first time detected in previously patent portal vein, presence of hyperdense thrombus on imaging, absent or limited collateral circulation, dilated portal vein at the site of occlusion) Ch: Chronic (no hyperdense thrombus; previously diagnosed PVT on follow-up, portal cavernoma and clinical features of portal hypertension) As: Asymptomatic S: Symptomatic: features of acute PVT (with or without acute bowel ischemia) or features of portal hypertension

Extent of portal vein system occlusion S: Splenic vein M: Mesenteric vein SM: Both

Type and presence of underlying liver disease

Cirrhotic, non-cirrhotic liver disease, post-liver transplant, hepatocellular carcinoma, local malignancies and associated conditions