title: Over-the-wire US catheter probe as an adjunct to ERCP in the detection of choledocholithiasis.
abstract: BACKGROUND
  Intraductal ultrasound (IDUS) as an adjunct to ERCP for detection of extrahepatic bile duct stones is technically easy, accurate, and safe. This prospective study evaluated IDUS with an "over-the-wire" catheter US probe as an adjunct to ERCP.
  
  
  METHODS
  Sixty-five patients, highly suspected to have choledocholithiasis, underwent IDUS during ERCP. The IDUS probe was inserted by means of the duodenoscope into the bile duct without performing a sphincterotomy. All stones identified by IDUS or retrograde cholangiography were removed with either a basket or retrieval balloon after endoscopic sphincterotomy.
  
  
  RESULTS
  The final diagnosis was choledocholithiasis in 59 patients. Bile duct diameter ranged from 0.6 to 2.3 cm and stone size from 2 mm to 2 cm. IDUS successfully identified all stones in these patients. IDUS resulted in 2 false-positive diagnoses in the remaining 6 patients without stones (overall accuracy 97%, sensitivity 100%, specificity 67%). Cholangiography detected stones in 55 of the patients with stones (accuracy 94%, sensitivity 93%, specificity 100%).
  
  
  CONCLUSIONS
  IDUS, a safe, technically easy procedure, is highly accurate in the detection of extrahepatic bile duct stones regardless of the diameter of the bile ducts. The "over-the-wire" technique preserves access to the cannulated duct. IDUS is an excellent adjunct to ERCP for the diagnosis of choledocholithiasis. IDUS differentiates stones from air bubbles and prevents unnecessary sphincterotomy.
authors.affiliation: Department of Internal Medicine, Taiwan Municipal Hospital, Taiwan, Republic of China.
authors.forename: L J
authors.initials: LJ
authors.lastname: Tseng
authors.forename: Y T
authors.initials: YT
authors.lastname: Jao
authors.forename: L R
authors.initials: LR
authors.lastname: Mo
authors.forename: R C
authors.initials: RC
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000295:instrumentation / Q000379:methods*; D019160:Endosonography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D042882:Gallstones / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity