Without treatment, most patients with complete venous obstruction die of liver failure within 3 yr. For patients with incomplete obstruction, the course varies.
Manifestations range from none (asymptomatic) to fulminant liver failure or cirrhosis. Symptoms vary depending on whether the obstruction occurs acutely or over time.
With cerebral venous drainage, it is rare that all the main veins (r-ijv, l-ijv and verts) would all be entirely occluded. Even then there are collaterals. CCSVI is analogous to incomplete obstruction Budd Chiari.