Liver lobe growth is regulated by portal blood supply.

<p>Portal vein ligation results in hyperperfusion of right lobes (RL)and caudate lobes (CL) and hypoperfusion of median and left lateral lobes (ML+LLL). The observed growth in the respective lobes correlates with the corresponding perfusion changes. (A) Rat liver anatomy and illustration of the surgical procedure for the portal vein ligation (PVL). Depicted is the positioning of the PVL (red cross). Ligated lobes are marked in gray. In case of a 70% pHx the lobes marked in gray are resected. (B) Liver lobe size adjustment at different postoperative days (POD) after of 70% PVL. Ligation of left lateral and median portal vein (70% of liver mass) results in lack of portal perfusion in the ligated 70% of the liver and hyperperfusion of right and caudate liver lobe, similar to the hyperperfusion observed after 70% pHx. Liver lobes adjust their weight according to the portal supply: Ligated lobes shrink to one third of their original weight whereas non-ligated lobes experience a 3-fold increase of their original weight, as seen after 70% pHx. Depicted is the time course of liver mass adaption after portal vein ligation as the relative liver lobe mass in proportion to the initial lobe weight (fold) at different postoperative days (POD).