Fig. 1.

Eighteenth follow-up survey of primary liver cancer conducted in 25,066 patients with HCC treated by hepatic resection between 1994 and 2005. Vp0 no tumor thrombus; Vp1 tumor thrombus distal to the second-order branches of the portal vein, but not involving the second-order branches; Vp2 tumor thrombus in the second-order branches of the portal vein; Vp3 tumor thrombus in the first-order branches of the portal vein and/or the main trunk of the portal vein and/or contralateral portal vein branch to the primarily involved