ABSTRACT
PURPOSE: Couinaud described segment IV as being equivalent to segments II and III, as the umbilical portion of the portal vein (PV), and its equal branch of segment II, originated from the transverse portion of the PV. On the contrary, Healey suggested the presence of left lateral and medial segments, on the basis of umbilical fissure. Recently, some author have claimed the branch of segment II originated from the distal portion of the ligamentum venosum (LV), and that this branch was not equal to, only a branch of, the umbilical portion. Our goal was to evaluate the surgical anatomy of the left lobe of the liver through dissecting Korean cadavers. METHODS: The number of cadavers dissected totaled 10. PV, its branches, and the LV were dissected and the length of the transverse portion measured. The distance between the origin of the transverse portion and that of the segment II branch were also measured. RESULTS: The branch of segment II originated from the distal portion of the LV in all 10 cases. The length of the transverse portion was 18.8+/-5.8 mm, and the distance between the origins of the LV and segment II branch was 7.0+/-3.1 mm. CONCLUSION: Considering the embryology of the liver, as well as the above result, the umbilical portion and segment II branch were not equal anatomic structures. The umbilical portion and LV are equal anatomic structures. The branch of segment II is only one of the branches of the umbilical portion. We think Healey's classification is more accurate for the left lobe of the liver.