title: ERCP with probe-based confocal laser endomicroscopy for the evaluation of dominant biliary stenoses in primary sclerosing cholangitis patients.
abstract: OBJECTIVE
  The incidence of cholangiocarcinoma (CCA) in primary sclerosing cholangitis (PSC) ranges between 7 and 14 %. Despite using multiple tissue sampling modalities, detection of CCA remains a challenge. Probe-based confocal laser endomicroscopy (pCLE) has been utilized to visualize subepithelial biliary mucosa in patients with indeterminate strictures. We assessed the technical feasibility and operating characteristics of pCLE in a cohort of PSC patients with dominant biliary strictures (DS).
  
  
  METHODS
  This was a chart review of a prospectively maintained database at a single tertiary referral center of 15 PSC patients with 21 dominant stenoses undergoing pCLE. A data collection sheet included demographics, ERCP, cholangioscopy, pCLE (Miami criteria), tissue sampling results, and follow-up to 12 months or liver transplantation. Operating characteristics for pCLE and ERCP tissue sampling were calculated.
  
  
  RESULTS
  Sufficient visualization of DS by pCLE was achieved in 20/21 (95 %). pCLE sensitivity, specificity, PPV, and NPV were 100 % (95 % CI 19.3-100 %), 61.1 % (95 % CI 35.8-82.6 %), 22.2 % (95 % CI 3.5-59.9 %), and 100 % (95 % CI 71.3-100 %), respectively, in detecting neoplasia. In comparison, concomitant tissue sampling yielded sensitivity, specificity, PPV, and NPV of 0 % (95 % CI 0-80.7 %), 94.4 % (95 % CI 72.6-99.1 %), 0 % (95 % CI 0-83.5 %), and 89.5 % (95 % CI 66.8-98.4 %), respectively.
  
  
  CONCLUSIONS
  pCLE achieves a high technical success rate in patients with PSC and DS. This single center, small series, suggests that pCLE may have a high sensitivity and negative predictive value to exclude neoplasia. If verified in larger prospective studies, the technology may be utilized to risk stratify dominant strictures in patients with PSC.
authors.affiliation: University of Colorado Anschutz Medical Campus, Mail Stop F735, Rm. AIP 2.031, 1635 Aurora Ct., Aurora, CO 80045, USA.
authors.forename: Muhannad
authors.initials: M
authors.lastname: Heif
authors.forename: Roy D
authors.initials: RD
authors.lastname: Yen
authors.forename: Raj J
authors.initials: RJ
authors.lastname: Shah
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000150:complications / Q000175:diagnosis*; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging / Q000473:pathology; D018281:Cholangiocarcinoma / Q000150:complications / Q000175:diagnosis*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000295:instrumentation* / Q000379:methods; D015209:Cholangitis, Sclerosing / Q000150:complications*; D002780:Cholestasis, Intrahepatic / Q000209:etiology*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000295:instrumentation; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity