High yields of small and flat adenomas with high-definition colonoscopes using either white light or narrow band imaging

Background & Aims: Detection of adenomas is an important goal of colonoscopy. Narrow band imaging (NBI) might highlight adenomas and lead to higher rates of adenoma detection. Methods: This was a randomized controlled trial of colonoscopy withdrawal in white light versus NBI in 434 patients aged 50 years or older with intact colons. All examinations were performed by a single experienced endoscopist with a known high detection rate of adenomas using high-definition, wide-angle (170 degrees field of view) colonoscopes. Results: There was no difference in the percent of patients with >= 1 adenoma for the entire cohort in white light (67%) versus NBI (65%) (P =.61) or in the subset of 257 patients with indication screening (58% vs 57%; P =.91). Both the prevalences of adenomas and the numbers of adenomas per colonoscopy are the highest ever reported in colonoscopy studies. The high prevalence rates of adenomas were accounted for by detection of large numbers of adenomas, including flat adenomas, which were <= 5 mm. Conclusions: NBI did not result in better detection of adenomas by an endoscopist with a known high detection rate using white light. This result does not exclude a possible benefit of NBI in reducing variation between endoscopists in detection of adenomas. The very high adenoma detection rate in this study suggests that high definition should be directly tested for its effect on detection of adenomas.