Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy

Background: An imaging modality that can be used to identity small stones a fter a biliary lithotripsy is required. Intraductal ultrasonography was eva luated by using percutaneous transhepatic cholangioscopy as the gold standa rd. Methods: Lithotripsy, under percutaneous transhepatic cholangioscopy guidan ce, was performed in 20 patients. A thin-caliber ultrasonic probe (2.0 mm i n diameter and 20 MHz frequency) was inserted into the bile duct through th e percutaneous tract after lithotripsy, and residual scenes were identified . This was followed by percutaneous transhepatic cholangioscopy. Results: In the extrahepatic bile ducts, intraductal ultrasonography provid ed images of all the stones demonstrated on cholangioscopy (n = 11). The se nsitivity was superior to that of cholangiography (P < 0.005). However, in the intrahepatic bile ducts, intraductal ultrasonography only visualized th e 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 diamet er were missed by cholangiography, but were visualized by the use of intrad uctal ultrasonography (P < 0.05). Conclusions: Intraductal ultrasonography is equivalent to cholangioscopy in the extrahepatic bile ducts. Cholangiography and intraductal ultrasonograp hy should be used in combination to image intrahepatic and extrahepatic sto nes. (C) 2001 Blackwell Science Asia Pty Ltd.