title: Preoperative assessment of congenital bile duct dilatation using intraductal US.
abstract: BACKGROUND
  Although congenital bile duct dilatation is frequently associated with biliary tract cancer, conventional cholangiography often does not demonstrate small ductal tumors. This is the first prospective study of the value of intraductal ultrasonography (US) in the examination of the extrahepatic bile ducts in patients with congenital bile duct dilatation.
  
  
  METHODS
  Intraductal US via a transpapillary route was used in consecutive patients with congenital bile duct dilatation. A 2.0 mm diameter, 20 MHz frequency catheter probe was used. The images were correlated with the results of histologic examination of the resection specimens.
  
  
  RESULTS
  Intraductal US was performed successfully via the transpapillary route in 8 of 10 patients. In the other 2 patients, the percutaneous transhepatic route was used. In the 6 patients with cylindrical dilatation, intraductal US demonstrated the entire extrahepatic bile duct. In 1 patient, it showed a bile duct cancer not demonstrated by cholangiography. In 2 of the 4 patients with cystic dilatation, intraductal US did not demonstrate the entire extrahepatic bile duct because of the low penetration depth of the probe. Percutaneous transhepatic cholangioscopy was required in these patients.
  
  
  CONCLUSIONS
  Intraductal US is useful for demonstrating cancers in the extrahepatic bile ducts in patients with congenital cylindrical ductal dilatation.
authors: Departments of Gastroenterology, Surgery, and Pathology, Jichi Medical School, Yakushiji, Tochigi, Japan.
authors: K
authors: K
authors: Tamada
authors: Y
authors: Y
authors: Yasuda
authors: T
authors: T
authors: Tomiyama
authors: A
authors: A
authors: Oohashi
authors: N
authors: N
authors: Kanai
authors: T
authors: T
authors: Aizawa
authors: S
authors: S
authors: Wada
authors: S
authors: S
authors: Tano
authors: T
authors: T
authors: Miyata
authors: Y
authors: Y
authors: Satoh
authors: K
authors: K
authors: Ido
authors: K
authors: K
authors: Kimura
mesh_terms: D000328:Adult; D001649:Bile Duct Diseases / Q000150:complications / Q000151:congenital* / Q000000981:diagnostic imaging; D001650:Bile Duct Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D017734:Bile Ducts, Extrahepatic / Q000000981:diagnostic imaging*; D004108:Dilatation, Pathologic / Q000150:complications / Q000151:congenital / Q000000981:diagnostic imaging; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies