Advanced endoscopic techniques improve IBD assessment

By Will Boggs MD

NEW YORK (Reuters Health) - 8/1/2019

Advanced endoscopic techniques allow for better assessment of mucosal healing and dysplasia in patients with inflammatory bowel disease (IBD), according to a new review.

"New technology in endoscopy is transforming the image definition, quality, and post-processing of images through optical and electronic wizardry," Dr. Marietta Iacucci from the University of Birmingham, UK, told Reuters Health by email. "We can now optically characterize inflammation, precancerous lesions, and early cancers with precision, so that endoscopy now can predict histology from biopsies."

Endoscopic assessments of inflammation and mucosal healing and early detection of neoplastic colonic lesions are important components of IBD management.

Dr. Iacucci and colleagues reviewed the technological advances in endoscopic techniques and how they contribute to the assessment and management of patients with IBD. High-definition (HD) endoscopy coupled with dye chromoendoscopy (DCE) provides much more detailed images of mucosal and vascular patterns, they note in their state-of-the-art report in Gut, online December 22.

Virtual chromoendoscopic (VCE) techniques, including narrow-band imaging (NBI), optical enhancement iSCAN, blue-laser imaging and confocal-laser endomicroscopy (CLE), can enhance details of tissue surfaces and blood vessels without any application of dye.

HD in combination with VCE allows assessment of inflammatory activity and the extent of IBD disease with a precision approaching that of histological assessment.

In patients with colonic IBD, HD colonoscopy with DCE fared much better than standard definition white-light endoscopy (WLE) in detecting dysplasia and intraepithelial neoplasia, but its effectiveness for IBD surveillance remains controversial. Cost/reimbursement, learning curve and procedure time remain key barriers.

CLE, a relatively new technique, is touted as "real-time histology" for its ability to facilitate diagnosis and decisions regarding the resectability of lesions, as well as its potential for differentiating between ulcerative colitis and Crohn’s disease, assessing inflammation, predicting outcomes and targeting biopsies and otherwise directing endoscopic management.

Other emerging technologies include molecular labeling to stratify patients for therapy and endocytoscopy to predict histology and to direct sampling for virtual biopsy.

"Endoscopic images in IBD are now becoming very detailed, precise, and accurate - images using modern endoscopes are now so detailed that trained experts can now predict early colonic mucosal changes," Dr. Iacucci said. "This may help in giving a prognosis to the patient with colitis (risk of relapse) and also permit curative resection of pre-cancerous and early cancerous lesions in IBD, thus sparing a total colectomy which most patients are very concerned about."

"Training in these new technologies is becoming very important as these technologies are widely available but we have still not taken full advantage of these technologies," she said. "We have designed online training modules which may help endoscopists to train themselves and help them achieve competence in these new technologies."

Dr. Rupert W. Leong of the University of Sydney, in Australia, who has researched various endoscopic techniques in the setting of IBD, told Reuters Health by email, "HD WLE is the standard and sufficient to report on the level of inflammation using standardized scoring systems, such as the endoscopic Mayo score for ulcerative colitis (UC), the Simple Endoscopic Score-CD (SES-CD), and the more newly developed UC Endoscopic Index of Severity (UCEIS). The absence of active inflammation is the target for treatment. No additional adjunct technologies are required."

"However, a higher target of treatment is restoration of the mucosal barrier and this is detected using confocal laser endomicroscopy," said Dr. Leong, who was not involved in the review. "Patients who have ongoing impaired mucosal-barrier function have ongoing intestinal symptoms even though they have achieved mucosal healing seen on WLE. Therefore, restoring mucosal barrier function might be an important target to treat patients' symptoms."

"In recent years, endoscopic detection and removal of pre-cancerous dysplasia has replaced the need for proctocolectomy in IBD patients with chronic colitis," Dr. Leong said. "This has led to reducing interval bowel cancers in IBD patients and decreased proctocolectomy. Many patients prefer endoscopic surveillance over surgical resection of the bowel."

"Most endoscopy units now are embracing HD WLE," he said. "The usefulness of additional adjunct technologies, such as NBI and iSCAN, is debated given the need for additional training and that they might not be as useful in the setting of inflammation. For IBD subjects at high risk of dysplasia, they should be referred to an endoscopist with experience and knowledge of surveillance protocols."

SOURCE: Gut 2018.

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