title: Limited applicability of chromoendoscopy-guided confocal laser endomicroscopy as daily-practice surveillance strategy in Crohn's disease.
abstract: OBJECTIVE
  Patients with longstanding ulcerative colitis have an increased risk for developing colorectal cancer (CRC). Although the risk for ulcerative colitis is well-established, for Crohn's disease data are contradictory. This study aimed to determine the number of patients with Crohn's disease with dysplasia who are undergoing surveillance and to assess the diagnostic accuracy of chromoendoscopy (CE) combined with integrated confocal laser endomicroscopy (iCLE) for differentiating dysplastic versus nondysplastic lesions.
  
  
  METHODS
  Patients with longstanding Crohn's colitis undergoing surveillance colonoscopy were included in this multicenter, prospective, cohort study. Surveillance was performed with CE, and lesions were assessed with iCLE for differentiation. All lesions were removed and sent for pathology as the reference standard.
  
  
  RESULTS
  Between 2010 and 2014, a total of 61 patients with Crohn's colitis were included in 5 centers. Seventy-two lesions, of which 7 were dysplastic, were detected in 6 patients (dysplasia detection rate 9.8%); none included high-grade dysplasia or cancer. Combined CE with iCLE for differentiating neoplastic from nonneoplastic lesions had accuracy of 86.7% (95% confidence interval [CI], 78.1-95.3), sensitivity of 42.9% (95% CI, 11.8-79.8), and specificity of 92.4% (95% CI, 80.9-97.6). For CE alone, this was 80.3% (95% CI, 70.7-89.9), 28.6% (95% CI, 5.1-69.7), and 86.4% (95% CI, 80.9-97.6). The study terminated early because of frequent failure of the endoscopic equipment.
  
  
  CONCLUSIONS
  This study shows a low incidence of dysplastic lesions found during surveillance colonoscopy in patients with longstanding extensive Crohn's colitis. The accuracy of both CE alone and CE in combination with iCLE was relatively good, although the sensitivity for both was poor. Because of frequent equipment failure, iCLE has limited applicability in daily practice as a surveillance strategy.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Linda K
authors.initials: LK
authors.lastname: Wanders
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Teaco
authors.initials: T
authors.lastname: Kuiper
authors.affiliation: Department of Gastroenterology, Dr. Horst Schmidt Klinik, Wiesbaden, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Kiesslich
authors.affiliation: Gastro Unit, Division of Endoscopy, Copenhagen University Hospital Herlev, Herlev, Denmark.
authors.forename: John G
authors.initials: JG
authors.lastname: Karstensen
authors.affiliation: Gastroenterology and Liver Services, Bankstown-Lidcombe Hospital, Sydney, Australia.
authors.forename: Rupert W
authors.initials: RW
authors.lastname: Leong
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
authors.affiliation: Department of Gastroenterology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Raf
authors.initials: R
authors.lastname: Bisschops
mesh_terms: D000293:Adolescent; D000328:Adult; D003113:Colonoscopy; D004396:Coloring Agents; D003424:Crohn Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology*; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008751:Methylene Blue; D018613:Microscopy, Confocal / Q000379:methods; D008875:Middle Aged; D011230:Precancerous Conditions / Q000000981:diagnostic imaging* / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D057832:Watchful Waiting / Q000379:methods; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D008751:Methylene Blue