title: Importance of conserving middle hepatic vein distal branches for homogeneous regeneration of the left liver after right hepatectomy.
abstract: BACKGROUND
  Liver regeneration enables repeat surgical procedures to achieve a potential cure in liver cancer patients. However, data regarding segmental regeneration and liver anatomy after liver resection are scarce. This study examined left liver regeneration after right hepatectomy and the impact of hepatic venous drainage on the regeneration of the paramedian sector (Couinaud's segment IV).
  
  
  METHODS
  Twenty patients in whom right hepatectomy with conservation of the middle hepatic vein (MHV) on healthy liver had been performed were analysed for segmental volumes and vascular anatomy. Volumetric analysis of left liver segments and three-dimensional MHV reconstruction were conducted using pre- and postoperative computed tomography. The volumetric proportions represented by each segment within the left liver were compared and MHV anatomy was analysed to determine its potential role in the regeneration of left liver segments.
  
  
  RESULTS
  After right hepatectomy, the proportion represented by segment IV within the left liver decreases by 13%, whereas the proportion represented by segments II and III increases by 15%. This heterogeneous regeneration is particularly observed in patients in whom a venous branch for segment IVb is sacrificed, leading to an altered outflow similar to that observed in MHV deprivation. The risk for venous branch deprivation in IVb is correlated to the depth of the bifurcation of the MHV in liver parenchyma.
  
  
  CONCLUSIONS
  It is crucial to conserve the MHV in its distal part if homogeneous left liver regeneration after right hepatectomy that will allow potential repeat liver resection is to be achieved.
authors.affiliation: Hepatobiliary Centre Unit 785, INSERM, University of Paris South, Villejuif, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Faitot
authors.forename: Eric
authors.initials: E
authors.lastname: Vibert
authors.forename: Chady
authors.initials: C
authors.lastname: Salloum
authors.forename: David Lee
authors.initials: DL
authors.lastname: Gorden
authors.forename: Franck
authors.initials: F
authors.lastname: Coscas
authors.forename: René
authors.initials: R
authors.lastname: Adam
authors.forename: Denis
authors.initials: D
authors.lastname: Castaing
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005602:France; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D006503:Hepatic Veins / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008115:Liver Regeneration; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome