Evolving endoscopic technologies for the detection of dysplasia in inflammatory bowel diseases

Patients with long-standing and extensive ulcerative colitis (UC) and colonic Chron's disease (CD) have an increased risk of CRC compared with the general population. Although no large controlled trials have proven that surveillance reduces mortality, cancer prevention in inflammatory bowel disease depends on the detection of dysplasia during scheduled surveillance colonoscopy and is widely recommended by gastroenterological associations. Dysplasia in IBD may occur in flat mucosa or in raised lesions (DALM) which have sometimes endoscopic features similar to adenoma (adenoma-like DALM). Recently, new endoscopic techniques to facilitate the distinction between dysplastic and actively inflamed or normal mucosa have been proposed. Chromoendoscopy significantly increases the sensitivity of detecting subtle dysplastic lesions and has emerged as the new standard of cancer surveillance in patients with IBD. Confocal laser endomicroscopy (CLE) is a novel technique that enables the endoscopist to obtain real time in vivo microscopic images of the gastrointestinal mucosa and can be used for targeting biopsies to relevant areas. CLE in conjunction with chromoendoscopy proved able to increase the diagnostic yield of dysplasia in ulcerative colitis and reduce the number of biopsies needed. The role of digital filtering technologies (virtual chromoendoscopy) and autofluorescence in IBD surveillance will be also discussed.