Table 1.

Classifications of PVTT.

Extent of tumor thrombus	Japanese Vp classification	Chinese Cheng’s classification
no PVTT	Vp0	NA
microvascular	NA	Type I0
segmental PV or above	Vp1	Type I
the second-order branches of PV	Vp2	Type I
the right or left PV	Vp3	Type II
the right and left PV	Vp4	Type II
the main trunk	Vp4	Type III
the superior mesenteric vein	Vp4	Type IV

PVTT, portal vein tumor thrombus; PV, portal vein; NA, not available.