Reproposal for Hjortsjo's segmental anatomy on the anterior segment in human liver.

Background A minimum, but necessary amount, of cancer-containing liver tissue is to be excised in patients who have poor liver function. To achieve that goal of excision, a limited hepatic resection has been carried out. However, performing subsegmentectomy of the anterior segment according to the conventional segmental anatomy introduced by Healey and Schroy or Couinaud is difficult. Because the transverse border between segments 5 and 8 was drawn as an imaginary line through the right portal vein, there is no anatomical structure indicating this border. Hypothesis Hjortsjo divided the anterior segment into 2 vertical segments according to the fissure in which a hepatic vein coursed. By including Hjortsjo's concept of segmental anatomy, new procedures will be added to hepatic surgery. Design Sixty-five cadaveric livers were dissected to confirm Hjortsjo's concept of segmental anatomy by investigating the vertical fissure that divides the anterior segment into 2 areas, concerning the relation between portal segmentation and the hepatic venous system of the anterior segment. Results The territories of the third-order portal branches of the anterior segment were divided into 2 (ventral and dorsal) areas with a vertical fissure and in its intersubsegmental plane, an independent hepatic vein, or a first-order branch of the middle or the right hepatic vein coursed. Conclusions These findings confirmed the certainty of Hjortsjo's concept of segmental anatomy of the anterior segment. This is relevant for developing new procedures in hepatic surgery. Its reproposal is opportune for adding it as another concept to the conventional segmental anatomy.