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."
Consecutive patients with clinically inactive, long-standing ulcerative colitis involving at least the left colon or patients with colonic Crohn's disease affecting at least one third of the colon were recruited from the Outpatient Clinic of the Gastroenterology Department at Hospital Clinic, Barcelona, Spain. A total of 60 patients were included in the prospective, randomized, crossover study.
Each patient underwent high-resolution NBI colonoscopy and high-resolution indigo carmine CE with an interval of three to eight weeks between procedures. The order in which the examinations were performed was randomized (1:1). All colonoscopies were conducted by one of two experienced endoscopists who were blinded to the endoscopic and histological findings obtained during the first procedure. The morphology, size and location of any visible lesion were recorded. Any suspicious lesions detected during the examinations were sampled or immediately removed after detection. Biopsy samples were processed and stained by using standard methods and were subsequently evaluated by an experienced gastrointestinal pathologist.
Chromoendoscopy identified 208 suspicious lesions and 12 dysplastic lesions, while NBI detected 136 suspicious lesions and 10 dysplastic lesions. Therefore, CE identified 50 percent more "suspicious" lesions, for a 20 percent incremental yield. The prevalence of dysplastic lesions among patients enrolled in the study was 21.7 percent. The percentage of missed neoplastic lesions was higher with NBI than with CE (31.8 percent vs. 13.6 percent), resulting in a miss rate risk difference of 18.2 percent. Mean withdrawal time of the endoscope for CE was significantly longer than that for NBI (26.87 minutes vs. 15.74 minutes).
The researchers concluded that NBI appears to be a less time-consuming and an equally effective alternative to CE for the detection of neoplasia, but with a higher miss rate, and so NBI cannot be recommended as the standard technique. As a consequence, they believe that CE should still be considered the technique of choice for detecting dysplasia in patients with long-standing IBD.
In an accompanying editorial, Charles N. Bernstein, MD, Department of Internal Medicine and IBD Clinical Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada, stated, "Pellise et al found a high rate of 22 percent of patients having dysplastic lesions, further promoting the value of color contrast endoscopy in searching for dysplasia, at least in the hands of an expert center prepared to biopsy up to 6 raised lesions per case. Contrary to the actual study conclusions, it seems to show a comparable merit of NBI to chromoendoscopy and a greater time efficiency. More studies of NBI in dysplasia surveillance in inflammatory bowel disease may clarify its role. However, even simpler than NBI might be white-light endoscopy with high-definition colonoscopes. For an incremental yield of finding dysplastic lesions, a study needs to be conducted to compare chromoendoscopy with white-light endoscopy with these newer generation and already widely used colonoscopes."
About the American Society for Gastrointestinal Endoscopy
Since its founding in 1941, the American Society for Gastrointestinal Endoscopy (ASGE) has been dedicated to advancing patient care and digestive health by promoting excellence in gastrointestinal endoscopy. ASGE, with nearly 12,000 members worldwide, promotes the highest standards for endoscopic training and practice, fosters endoscopic research, recognizes distinguished contributions to endoscopy, and is the foremost resource for endoscopic education. Visit www.asge.org and www.screen4coloncancer.org for more information and to find a qualified doctor in your area.
Endoscopy is performed by specially-trained physicians called endoscopists using the most current technology to diagnose and treat diseases of the gastrointestinal tract. Using flexible, thin tubes called endoscopes, endoscopists are able to access the human digestive tract without incisions via natural orifices. Endoscopes are designed with high-intensity lighting and fitted with precision devices that allow viewing and treatment of the gastrointestinal system.
Anne Brownsey | EurekAlert!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy