6533b82bfe1ef96bd128ce91

RESEARCH PRODUCT

Endoscopic surveillance in ulcerative colitis: smart biopsies do it better.

subject

description

Patients with ulcerative colitis (UC) have a significantly higher risk for the development of colitisassociated colorectal cancer. Endoscopic surveillance is recommended. The growth pattern of dysplastic tissue is often multifocal and flat. Thus, significant lesions might be overlooked. Multiple random biopsies are recommended, but cannot eliminate the possibility of missed cancers with severe consequences for the patient. Chromoendoscopy with methylene blue or indigo carmine can unmask flat lesions and may solve this problem. In addition, confocal laser endomicroscopy enables in vivo histology with subcellular resolution during ongoing colonoscopy and leads to highly selected mucosal biopsies. In UC, inflammation and dysplasia are first limited to the mucosa. Chromoendoscopy is a simple adjunct to white light endoscopy. Different dyes can be applied onto the mucosal surface. Methylene blue as an absorptive stain helps to characterize the surface architecture because of the more stable staining pattern as compared with indigo carmine. Methylene blue outlines the pits of normal and neoplastic tissue and this typical staining pattern is visible for 10‐20 minutes after application. Indigo carmine is a contrast stain. It pools in mucosal grooves and depressed areas, highlighting the mucosal surface for a short time. The goal of any staining is to unmask flat neoplastic lesions. Chromoendoscopy allows clarifying the borders of the so-called circumscribed lesions. Magnification of the very newly available high-definition endoscopes allows detailed surface analysis of the stained lesions. Neoplastic and non-neoplastic tissue can be differentiated based on regular or irregular staining pattern (pit pattern classification1), which subsequently leads