Real-time Diagnosis of Pseudopolyps During Colonoscopy

Overview

Significance: Biopsy of potentially benign pseudopolyps and the surrounding mucosa adds expense and prolongs the time of endoscopic procedures. Use of endoscopic technologies could decrease the need and expense of endoscopic biopsy for these lesions. Hypothesis: Pseudopolyps will have a distinctive pattern with the specialized imaging techniques of high definition imaging, narrow band imaging, and endoscopic dye-spraying techniques using indigo carmine which will predict diagnosis without biopsy. 100 patients with inflammatory bowel disease will be enrolled in the study. Following a standard bowel preparation, each patient will be evaluated using standard endoscopic equipment. All patients will receive a standard bowel preparation (sodium phosphate, PEG-3350, or magnesium citrate based preparations). All colonoscopic evaluations will be performed for indications unrelated to the present study, including evaluation of response to medical treatment, routine surveillance exams for dysplasia, diarrhea, or rectal bleeding. Polypoid lesions will be examined using four consecutive methods: (a) high definition white light, (b) narrow band imaging, (c) chromoendoscopy (high definition white light with indigo carmine dye-spraying), and (d) histologic examination following biopsy. The flat mucosa surrounding the polypoid lesions will also be examined using theses four techniques in an effort to identify dysplastic tissue associated with these polypoid growths. High definition white light is the standard imaging modality used for colonoscopy. Narrow band imaging (blue wavelength of light) is also used routinely and is available on all current generation colonoscopes with the press of a button. Our division routinely uses chromoendoscopy as part of surveillance for dysplasia in patients with inflammatory bowel disease. Dye spraying catheters or flushing will be utilized for dye application to mucosa. The dye used will be indigo carmine. Directed biopsy specimens will then be performed using a multibite forceps for targeted biopsies. Routine biopsies will be performed as clinically indicated. Pathology slides will be reviewed by the gastrointestinal pathologists at the University of Miami. The gastroenterologist's interpretation based on each of the three successive endoscopic methods will then be compared to the histologic evaluation with each individual lesion serving as its own control.

The colonoscopy with biopsies will be done as standard of care; additional biopsies will be taken for research purposes as detailed above. All of the imaging techniques are part of the accepted standard of care as follows: high definition white light, narrow band imaging, chromoendoscopy, and histologic examination following biopsy. Comparison of the predictive values of the imaging modalities in predicting histology from biopsy underlies the primary question of this research protocol. Cost analysis of modalities versus histology will also be performed. Time for use of the individual modalities will be recorded. Subjects will be identified by one of the investigators during their outpatient clinic visits or while inpatient at University of Miami Hospital. Subjects who meet the inclusion/exclusion criteria and are scheduled to undergo a colonoscopy for standard of care purposes will be asked to participate in the study. Patients over 18 years of age with a confirmed diagnosis of inflammatory bowel disease with plans for routine colonoscopic evaluation and able to provide informed consent will be included.