What is portal vein embolization for?

Pv. We usually use portal vein embolization to preferentially grow a segment of liver that we choose while shrinking a segment of liver we want to get rid of. For instance, if we want to respect part of the liver we can first get the remaing liver to hypertrophy by embolizing the vein that feeds the segment that's coming out.
Liver resection. Pve is used in the preoperative planning and treatment of patients with liver tumors anticipating major liver resections. Pve is used where the liver tumors are large and initial removal will result in only a small portion of normal liver remaining. Embolization of the tumor cuts off the blood supply and the remaining normal liver grows larger over several weeks, allowing major resection.