Limited resection based on reclassification of segment 8 of the liver.

Liver vein patterns which differ from those previously described are occasionally encountered during surgery. Therefore, we reclassified the anterosuperior segment (S8) into S8v (ventral area) and S8d (dorsal area), and the right paramedian sector into the ventral segment (S8v+S5) and the dorsal segment (S8d) based on portal and hepatic vein patterns. Using this new classification, we performed three types of limited resection of S8 in six patients with neither major nor minor procedural complications including biliary leaks, and no blood transfusion. This new classification allows development of surgical procedures where resection is limited to the portal unit and tumor.