Table 1.

Classifications of PVT based on anatomic extent by Yerdel et al [5].

Classification	Occlusion of portal vein	Extension of thrombus
Grade 1	Minimal or partial thrombosis of the portal vein with <50% occlusion	With or without minimal SMV involvement
Grade 2	>50% and complete thrombosis of the portal vein	With or without minimal SMV involvement
Grade 3	Complete thrombosis of the portal vein	Proximal SMV is occluded with patent distal SMV
Grade 4	Complete thrombosis of the portal vein	Proximal and distal SMV occlusion

Abbreviation: SMV, superior mesenteric vein.