Editing Liver (section)

=== '''Hepatic     veins''' ===

** Do not correspond with      portal segmentation
** Major hepatic veins lie      between the four main sectors
** There are only two major      hepatic veins entering the IVC
** Course
*** Right hepatic vein - runs       in the right scissura between the anterior and posterior sectors of the       right liver, and drains most of the right liver. Usually the largest,       but also the most variable. Enters IVC at about the upper pole of the       caudate lobe, a few mm lower than the left hepatic vein.
*** Left and middle hepatic       veins usually join intra-hepatically and enter the left side of the IVC       as a single vessel, but with the common trunk usually only 5mm in length       before reaching IVC.
**** Left hepatic vein runs in        the left scissura between segments II and III and drains those segments        only. Takes the ligamentum venosum. Situated in the posterior 2cm of        the left fissure, making up part of the posterior edge of liver, only        being covered by connective tissue of the left triangular ligament.
***** Also receives tributaries         from the vein of the umbilical fissure and a posterior branch from the         posterior part of the left liver, which can sometimes still allow         segment IV to drain after resection of middle hepatic vein
**** Middle hepatic vein runs        in the portal scissura between segment IV and the right anterior        sector, and drains segment IV and some of the right anterior sector
*** Umbilical vein, if patent,       usually empties into left hepatic vein, in umbilical fissure
*** Small inferior veins from       segment VIII and caudate lobe drain directly into IVC
**** In 15% of patients, there        is a moderately large right vein here, termed the accessory right        hepatic vein
**** Approach and ligate these        by mobilising the liver then exposing to the opposite side of the vein
*** Also common tributary from       caudate love into left hepatic vein
*