title: Intrahepatic bile duct dilatation after percutaneous radiofrequency ablation for hepatocellular carcinoma: impact on patient's prognosis.
abstract: BACKGROUND
  Percutaneous radiofrequency ablation (RFA) has been widely accepted as an alternative to surgery for small hepatocellular carcinoma (HCC). In RFA, a portion of liver tissue surrounding tumour is also ablated to achieve a safety margin. The intrahepatic bile duct may be injured and result in chronic bile duct dilatation upstream of the injured site. However, the impact of such an injury on the overall prognosis has been unclear.
  
  
  METHODS
  Patients who showed bile duct dilatation following RFA were identified by a retrospective review of imaging studies. Each dilatation was classified as mild (limited to one hepatic subsegment) or severe (affecting two or more subsegments). The relation between the incidence of intrahepatic bile duct dilatation and HCC recurrence or survival was analysed using proportional hazard models.
  
  
  RESULTS
  Among 589 consecutive HCC patients treated with RFA, 70 (11.9%) and 21 (3.6%) patients showed mild and severe bile duct dilatation respectively. Patients with severe dilatation, but not those with mild dilatation, had lower survival and higher HCC recurrence than patients without dilatation. Severe dilatation, but not mild dilatation, was significantly associated with death [hazard ratio (HR) 2.17, P=0.035] and recurrence (HR 2.89, P<0.001).
  
  
  CONCLUSIONS
  Whereas mild bile duct dilatation after RFA is clinically negligible, bile duct dilatation affecting two or more subsegments should be regarded as a complication that may affect the prognosis and should be observed carefully.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. ykon-tky@umin.ac.jp
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kondo
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Shiina
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tateishi
authors.forename: Toru
authors.initials: T
authors.lastname: Arano
authors.forename: Koji
authors.initials: K
authors.lastname: Uchino
authors.forename: Kennichiro
authors.initials: K
authors.lastname: Enooku
authors.forename: Eriko
authors.initials: E
authors.lastname: Goto
authors.forename: Hayato
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Ryota
authors.initials: R
authors.lastname: Masuzaki
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Hajime
authors.initials: H
authors.lastname: Fujie
authors.forename: Tadashi
authors.initials: T
authors.lastname: Goto
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000368:Aged; D001653:Bile Ducts, Intrahepatic / Q000293:injuries / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D004108:Dilatation, Pathologic / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007564:Japan; D008113:Liver Neoplasms / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed