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° 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.
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Materials and Methods
The study was approved by the Institutional Review Board at Indiana University/Purdue University Indianapolis/Clarian Health Partners. Patients were eligible if they were aged 50 years and older and undergoing colonoscopy for colorectal cancer screening, postpolypectomy surveillance, or other indications for which the primary goal of the examination was detection of neoplasia. Patients were excluded if they had previous colorectal cancer, had previous surgical resection of the colon or rectum,
Results
Table 1 shows the demographics of the 2 study arms by age, sex, indication for the procedure, insertion time, and withdrawal time. There were no differences between the 2 arms in the demographics, indications, or procedure times except for mean withdrawal time, which was 0.4 minutes longer in the NBI arm (P = .003). The most common indication for colonoscopy in the study was colorectal cancer screening (Table 1).
Table 2 demonstrates the prevalence rates of adenomas and total numbers of adenomas
Discussion
In this report, we describe a randomized controlled trial comparing the use of white light with NBI for the purpose of finding adenomatous polyps. The study was performed by a single examiner with dedicated interest in colonoscopy and previous documentation of high adenoma detection rates using standard-definition colonoscopes in white light.16 Using high-definition colonoscopes, which produce a video signal with 2.25 times the number of visible horizontal scan lines (1080) compared with
