Real-time Diagnosis of Pseudopolyps During Colonoscopy

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.