title: Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy.
abstract: BACKGROUND
  An imaging modality that can be used to identity small stones after a biliary lithotripsy is required. Intraductal ultrasonography was evaluated by using percutaneous transhepatic cholangioscopy as the gold standard.
  
  
  METHODS
  Lithotripsy, under percutaneous transhepatic cholangioscopy guidance, was performed in 20 patients. A thin-caliber ultrasonic probe (2.0 mm in diameter and 20 MHz frequency) was inserted into the bile duct through the percutaneous tract after lithotripsy, and residual stones were identified. This was followed by percutaneous transhepatic cholangioscopy.
  
  
  RESULTS
  In the extrahepatic bile ducts, intraductal ultrasonography provided images of all the stones demonstrated on cholangioscopy (n = 11). The sensitivity was superior to that of cholangiography (P < 0.005). However, in the intrahepatic bile ducts, intraductal ultrasonography only visualized the stones located in the cannulated lobe. Extrahepatic stones smaller than 5.0 mm in diameter or in a common hepatic duct larger than 15.0 mm in diameter were missed by cholangiography, but were visualized by the use of intraductal ultrasonography (P < 0.05).
  
  
  CONCLUSIONS
  Intraductal ultrasonography is equivalent to cholangioscopy in the extrahepatic bile ducts. Cholangiography and intraductal ultrasonography should be used in combination to image intrahepatic and extrahepatic stones.
authors.affiliation: Department of Gastroenterology, Jichi Medical School, Yakushiji, Tochigi, Japan. tamadaki@jichi.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: A
authors.initials: A
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Tomiyama
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: Y
authors.initials: Y
authors.lastname: Satoh
authors.forename: T
authors.initials: T
authors.lastname: Higashizawa
authors.forename: K
authors.initials: K
authors.lastname: Ido
authors.forename: K
authors.initials: K
authors.lastname: Sugano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D002758:Cholangiography / Q000379:methods*; D005260:Female; D042882:Gallstones / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods*