title: Diagnostic Utility of Endoscopic Retrograde Cholangiography/Intraductal Ultrasound (ERC/IDUS) in Distinguishing Malignant from Benign Bile Duct Obstruction.
abstract: OBJECTIVE
  Accurately differentiating malignant diseases from benign ones in patients having bile duct obstruction is of significant importance and remains a major clinical problem. This study investigated the diagnostic yield of endoscopic retrograde cholangiography/intraductal ultrasound (ERC/IDUS) in distinguishing malignant from benign bile duct obstruction and assessed some image findings from ERC/IDUS which might be useful in differentiation.
  
  
  METHODS
  From January 2008 to January 2015, patients who underwent ERC/IDUS for bile duct obstruction were enrolled. Patient's ERC/IDUS diagnosis was compared with the final diagnosis determined by pathologic findings and/or clinical outcome of follow-up.
  
  
  RESULTS
  One hundred and ninety-three patients with bile duct obstruction were included. IDUS correctly identified 94 of 97 malignant diseases and 76 of 96 benign diseases with sensitivity, specificity, and accuracy rate of 96.91, 79.17, and 88.08 %, respectively. Additionally, the accuracy rate of IDUS for diagnosis of proximal bile duct obstruction was higher than that of distal bile duct obstruction (98.08 vs. 82.73 %, p = 0.006). Besides, there was a significant difference in the length at the obstruction site between benign and malignant diseases (13.76 ± 7.37 vs. 19.97 ± 11.37 mm, p < 0.001) as well as thickness of bile duct wall at the site of obstruction (3.06 ± 0.92 vs. 7.03 ± 3.70 mm, p = 0.008). Biliary wall thickness >7 mm without extrinsic compression had a positive predictive value (PPV) of 100 % for including malignancy, while length ≧20 mm demonstrated a PPV of 93.44 %.
  
  
  CONCLUSIONS
  ERC/IDUS is effective in distinguishing malignant from benign bile duct obstruction, thus helping in further clinical management.
authors.affiliation: Digestive Endoscopy Center, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. chenlu10101@163.com.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.affiliation: Digestive Endoscopy Center, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. luyifl@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Digestive Endoscopy Center, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. wujiach@yeah.net.
authors.forename: Jia-Chuan
authors.initials: JC
authors.lastname: Wu
authors.affiliation: Digestive Endoscopy Center, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. likebie@126.com.
authors.forename: Like
authors.initials: L
authors.lastname: Bie
authors.affiliation: Digestive Endoscopy Center, Shanghai International Medical Center, 4358 Kangxin Road, Shanghai, 201318, China. xialu@medmail.com.cn.
authors.forename: Lu
authors.initials: L
authors.lastname: Xia
authors.affiliation: Digestive Endoscopy Center, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. gbercp616@163.com.
authors.forename: Biao
authors.initials: B
authors.lastname: Gong
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000175:diagnosis*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D002779:Cholestasis / Q000175:diagnosis*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Accuracy; Bile duct obstruction; Endoscopic retrograde cholangiopancreatography; Intraductal ultrasound; Length; Wall thickness