title: Absent middle hepatic vein in a right liver graft donor.
abstract: BACKGROUND
  The middle hepatic vein (MHV) is normally in form of a large trunk lying within the midplane of the liver. An anomaly in form of two separate trunks, each draining segment V/VIII and segment IV, has been described by Couinaud but not been well documented in the literature.
  
  
  METHODS
  We report a right liver donor in whom the MHV was absent and not encountered during liver transection along the midplane of the liver.
  
  
  RESULTS
  On computed tomography (CT) scan and intraoperative ultrasonography, there was a large segment VIII hepatic vein mistaken as the MHV on preoperative assessment and a large segment IV hepatic vein close to the ligamentum venosum. CT volumetry based on either segment VIII or IV hepatic vein led to major error in liver volume calculation. Transection of the liver guided by segment VIII or IV hepatic vein would lead to sacrifice of liver parenchyma unnecessarily or presence of necrotic liver in the graft.
  
  
  CONCLUSIONS
  Absent MHV is a rare anomaly. It is revealed by careful study of the CT scan.
authors.affiliation: Department of Surgery, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China. stfan@hku.hk
authors.forename: Sheung Tat
authors.initials: ST
authors.lastname: Fan
authors.forename: Yik
authors.initials: Y
authors.lastname: Wong
mesh_terms: D000328:Adult; D005260:Female; D006498:Hepatectomy; D006503:Hepatic Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D016031:Liver Transplantation; D019520:Living Donors; D014057:Tomography, X-Ray Computed