title: Endosonography- vs. endoscopic retrograde cholangiopancreatography-based strategies in the evaluation of suspected common bile duct stones in patients with normal transabdominal imaging.
abstract: BACKGROUND
  Endosonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are highly accurate techniques for evaluating common bile duct stones.
  
  
  OBJECTIVE
  To compare the clinical impact and costs of EUS- and ERCP-based strategies for evaluating patients with suspected common bile duct stones but normal transabdominal imaging.
  
  
  METHODS
  The costs of EUS- vs. ERCP-based strategies were compared in patients with suspected acute biliary obstruction from common bile duct stones but normal transabdominal imaging.
  
  
  RESULTS
  Over a 15-month period, 110 patients were recruited. EUS detected a common bile duct lesion in 73% (common bile duct stones: 68%; pancreatic cancer: 2%; ampulla tumour: 2%; cholangiocarcinoma: 1%). The sensitivity, specificity, positive predictive value and negative predictive value of EUS were 98%, 100%, 100% and 93%, respectively. EUS prevented 30% unnecessary ERCP. The mean difference in cost per patient between EUS- and ERCP-based strategies was US$166. When stratified according to clinical indications, an EUS-based strategy was costlier only in suspected biliary sepsis. Costs were similar when the indications were cholestatic jaundice, acute pancreatitis and cholestasis.
  
  
  CONCLUSIONS
  EUS prior to biliary interventions in patients with suspected common bile duct stones prevented unnecessary ERCP. It allowed a definitive diagnosis to be made prior to more invasive procedures.
authors: Division of Gastroenterology, Department of Medicine, Changi General Hospital, Singapore. tiing_leong_ang@cgh.com.sg
authors: T L
authors: TL
authors: Ang
authors: E K
authors: EK
authors: Teo
authors: K M
authors: KM
authors: Fock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001660:Biliary Tract Diseases / Q000175:diagnosis; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000191:economics* / Q000379:methods; D019160:Endosonography / Q000009:adverse effects / Q000191:economics* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies