title: Assessment of portal vein invasion by bile duct cancer using intraductal ultrasonography.
abstract: OBJECTIVE
  We recently reported on the contribution of intraductal ultrasonography (IDUS) to the regional staging of bile duct cancer, and we present here the first detailed study of the value of IDUS in assessing the portal vein invasion by bile duct cancer.
  
  
  METHODS
  Preoperative assessment of portal vein invasion was performed by IDUS via a percutaneous tract or via transpapillary route in 18 patients with extrahepatic bile duct cancer. Various probes, with diameters of 1.4, 2.0, 2.4, 2.6, and 3.2 mm, and frequencies of 7.5, 15, 20, and 30 MHz, were used. All patients additionally underwent endoscopic ultrasonography (EUS) and angiography. In the first six cases, the IDUS and EUS images were analyzed retrospectively without the knowledge of operative results or the other imaging tests. In the remaining 12 cases, IDUS and EUS images were prospectively reviewed prior to surgery, without knowledge of the angiographic findings. The gold standard for the results of IDUS, EUS and angiography was the histopathological findings in 17 resected tumors, and the intraoperative findings in one patient who did not undergo resective surgery.
  
  
  RESULTS
  IDUS was able to demonstrate the portal vein in all cases. Its accuracy in diagnosing portal vein invasion was 100% for all locations. EUS was useful in assessing portal vein invasion at the middle and distal bile duct (the accuracy was 91%), but was not useful in assessing invasion at the proximal bile duct (the accuracy was 57%).
  
  
  CONCLUSIONS
  IDUS proved useful for assessing the extension of cancer invasion into the portal vein, even in proximal bile duct tumors.
authors.affiliation: Department of Gastroenterology, Jichi Medical School, Tochigi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: K
authors.initials: K
authors.lastname: Ido
authors.forename: N
authors.initials: N
authors.lastname: Ueno
authors.forename: M
authors.initials: M
authors.lastname: Ichiyama
authors.forename: T
authors.initials: T
authors.lastname: Tomiyama
authors.forename: T
authors.initials: T
authors.lastname: Nishizono
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: T
authors.initials: T
authors.lastname: Noda
authors.forename: S
authors.initials: S
authors.lastname: Tano
authors.forename: T
authors.initials: T
authors.lastname: Aizawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D017734:Bile Ducts, Extrahepatic / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D004724:Endoscopy; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011169:Portal Vein / Q000000981:diagnostic imaging*; D011859:Radiography; D018084:Ultrasonography, Interventional