Role of chromoendoscopy in colon cancer surveillance in inflammatory bowel disease

Abstract

Inflammation in the intestine is a well-known risk factor for neoplastic changes in the mucosa. In fact, it has been shown that long-standing ulcerative colitis and colonic Crohn's disease have a significantly increased risk for developing colorectal cancer, although the estimates vary widely between studies. Conventional colonoscopy is effective in detecting polypoid changes in the mucosa. However, it is now generally accepted that neoplastic changes in colitis are frequently flat and depressed, which are easily missed by use of routine colonoscopy. The introduction of chromoendoscopy, especially in combination with magnifying endoscopy, has greatly advanced our means to detect and differentiate neoplastic lesions in the colorectum. Accumulating evidence-based data indicate that implementation of chromoendoscopy into colon cancer surveillance protocols for patients with inflammatory bowel disease is effective. However, the introduction of chromoendoscopy into surveillance programs requires meticulous training and further studies to compare the value of chromoendoscopy to newer endoscopic devices and techniques, such as narrow band imaging.

Feasibility of confocal endomicroscopy in the diagnosis of pediatric gastrointestinal disorders

“…In adults, several studies have validated these techniques in differentiating neoplastic from non-neoplastic lesions [26][27][28][29] , diagnosis of neoplastic lesions in flat and depressed lesions in the colorectum, and in cancer surveillance in patients with long-standing ulcerative colitis [30,31] . Confocal endomicroscopy is a newly developed tool that enables surface and subsurface imaging of living cells in the mucosa during ongoing endoscopy.…”

The Future of Surgical Management of Inflammatory Bowel Disease

“…From a practical standpoint, recently developed techniques of surveillance using chromoendoscopy hold promise for better and earlier treatment of patients with colitis associated dysplasia. 8 Better yet, however, would be easily measurable metabolic or genetic factors that would predict a patient's risk for the development of cancer without the difficulties of colonoscopy. It is somewhat concerning that the new biologic treatments have been shown to increase the risk of some malignancies.…”

Advanced Endoscopic Imaging Techniques for the Study of Colonic Mucosa in Patients with Inflammatory Bowel Disease

“…CE can visualize minute changes that might occur in the surface pattern of the GI tract [3]. CE associated to high-resolution magnifying endoscopes provides a better mucosal surface analysis [4]. Three types of dye agents can be used: (I) absorptive agents (Lugol, methylene blue, cresyl violet and toluidine blue), (II) contrast agents (acetic acid, indigo carmine) and (III) reactive staining agents (Congo red, phenol red), being applied via standard spraying or biliary ERCP catheters [4][5][6].…”

“…CE associated to high-resolution magnifying endoscopes provides a better mucosal surface analysis [4]. Three types of dye agents can be used: (I) absorptive agents (Lugol, methylene blue, cresyl violet and toluidine blue), (II) contrast agents (acetic acid, indigo carmine) and (III) reactive staining agents (Congo red, phenol red), being applied via standard spraying or biliary ERCP catheters [4][5][6]. These dyes react differently with the mucosa: absorptive stains are absorbed by specific epithelial cells, contrast stains penetrate mucosal crevices improving the surface visualization and mucosal irregularities, while reactive stains produce a chemical reaction with specific cellular constituents, resulting in a colour change.…”

“…To enlarge the image, magnifying endoscopes "zoom in" by using a movable lens which improves imaging of fine mucosal structures and the microvascular network. A transparent cap is fixed at the tip of the endoscope for maintaining a distance of 2-3 mm between mucosa and the endoscope, to obtain a focused image [4].…”