Chromoscopy-guided endomicroscopy increases the diagnostic yield of intraepithelial neoplasia in ulcerative colitis

Because of the large number of biopsy specimens, surveillance colonoscopy in ulcerative colitis (UC) is currently time consuming and significant flat lesions still may be missed. In this study we assessed the value of combined chromoscopy and endomicroscopy for the diagnosis of intraepithelial neoplasias in a randomized controlled trial.

A total of 161 patients with long-term UC in clinical remission were randomized at a 1:1 ratio to undergo conventional colonoscopy or chromoscopy with endomicroscopy. Eight patients were excluded because of insufficient bowel preparation. In the conventional colonoscopic group (n = 73), random biopsy examinations and targeted biopsy examinations were performed. In the endomicroscopy group (n = 80), circumscribed mucosal lesions were identified by chromoscopy and evaluated for targeted biopsy examination by endomicroscopy. The primary outcome analysis was based on the detection of neoplasias.

By using chromoscopy with endomicroscopy, 4.75-fold more neoplasias could be detected (P = .005) than with conventional colonoscopy, although 50% fewer biopsy specimens (P = .008) were required. If only circumscribed lesions would have been biopsied in the first group, the total number of biopsy specimens could have been reduced by more than 90%. A total of 5580 confocal endomicroscopic images from 134 circumscribed lesions were compared with histologic results. The presence of neoplastic changes could be predicted by endomicroscopy with high accuracy (sensitivity, 94.7%; specificity, 98.3%; accuracy, 97.8%).

Endomicroscopy based on in vivo histology can determine if UC lesions identified by chromoscopy should undergo biopsy examination, thereby increasing the diagnostic yield and reducing the need for biopsy examinations. Thus, chromoscopy-guided endomicroscopy may lead to significant improvements in the clinical management of UC.