OAK BROOK, Ill.―A new study from Spain finds that narrow band imaging appears to be a less time-consuming and equally effective alternative to chromoendoscopy for the detection of dysplasia (abnormal growths) in patients with long-standing inflammatory bowel disease. However, this study demonstrated higher miss rates for detection of lesions by narrow band imaging as compared with chromoendoscopy, and the authors concluded that narrow band imaging cannot be recommended as the standard technique. The study appears in the October issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE).
Inflammatory bowel disease (IBD) is the general name for diseases that cause inflammation in the small intestine and colon, which include Crohn’s disease and ulcerative colitis. IBD patients are at high risk for developing dysplasia and colorectal cancer. Chromoendoscopy (CE) is used for dysplasia surveillance in IBD patients. It is a special technique used in conjunction with endoscopy to improve visualization of the mucosa or lining of the intestine and can help the endoscopist find abnormalities that are present during the endoscopic examination which may be difficult to identify using only “white light” endoscopy. Chromoendoscopy is performed by spraying specialized nonpermanent stains or dyes on the lining of the intestine during the endoscopic procedure.
Narrow band imaging (NBI) with endoscopy offers the potential for improved visualization and was developed to enhance certain mucosal or vascular characteristics so that abnormal growths are visualized better. It uses a special filter to illuminate tissue in the lining of the intestines with light at specific wavelengths, which enhances underlying vasculature and produces the greatest contrast between the vessels and surrounding mucosa. This can help the endoscopist see the margins of an abnormal growth better and assist in determining which areas are the best to biopsy.
“In recent years, several studies have shown that chromoendoscopy is more accurate in detecting dysplasia in patients with long-standing inflammatory bowel disease than conventional endoscopy,” said study lead author Maria Pellisé, MD, Gastroenterology Department, Institut de Malalties Digestives I Metabòliques, CIBERehd Hospital Clinic, Barcelona, Spain. “The aim of this study was to compare new-generation NBI systems with high-resolution imaging with CE for the early detection of colitis-associated dysplasia and cancer in patients with long-standing colonic IBD. We found that NBI is a useful technique for the detection of dysplasia in patients with long-standing IBD that offers several advantages including efficiency, ease of use, and agility. However, the relatively high rate of missed lesions with NBI prevents its recommendation as the new standard technique of use.”