title: Proposal for a reclassification of liver based anatomy on portal ramifications.
abstract: BACKGROUND
  Portal branching patterns that differ from those previously described are occasionally encountered during liver surgery.
  
  
  METHODS
  A total of 60 patients with normal intrahepatic venous anatomy underwent helical computed tomography during arterial portography (CTAP). Next, 3 dimensional portograms were reconstructed to verify the locations of the portal veins. Portal branching patterns in the right hemiliver were assessed.
  
  
  RESULTS
  In all 60 patients examined, the right anterior portal vein bifurcated into the ventral and dorsal branches. In 42 (70%) of 60 patients, some branches arose from the right posterior portal trunk. Between 1 and 3 branches (mean 2.3 branches per patient) coursed cranially, between 2 and 5 branches (mean 3.2 branches per patient) coursed caudally, and between 1 and 2 branches (mean 1.3 branches per patient) coursed laterally.
  
  
  CONCLUSIONS
  We propose that the right liver should be divided into 3 segments, which are designated as the right anterior, middle, and posterior segments.
authors.affiliation: Department of Academic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuou-ku Chiba 260-0856, Japan. acho@sis.seirei.or.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Cho
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okazumi
authors.forename: Yukimasa
authors.initials: Y
authors.lastname: Miyazawa
authors.forename: Harufumi
authors.initials: H
authors.lastname: Makino
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Miura
authors.forename: Gaku
authors.initials: G
authors.lastname: Ohira
authors.forename: Yushin
authors.initials: Y
authors.lastname: Yoshinaga
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tohma
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Kudo
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Matsubara
authors.forename: Munemasa
authors.initials: M
authors.lastname: Ryu
authors.forename: Takenori
authors.initials: T
authors.lastname: Ochiai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008099:Liver / Q000098:blood supply* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000033:anatomy & histology*; D014057:Tomography, X-Ray Computed