Objectives: The benefits of narrow band imaging (NBI) on enhancing colorectal adenoma detection remain questionable. We tested whether the new generation of NBI (190-NBI), which is twice as bright as the previous version, would improve adenoma detection when compared with high-definition white light (HD-WL) colonoscopy.
Methods: It was a randomized controlled trial with tandem colonoscopy. We recruited patients who underwent colonoscopy for symptoms, screening, or surveillance. Patients were randomized for the use of either 190-NBI or HD-WL on withdrawal. Tandem colonoscopy was performed by using the same assigned colonoscope and withdrawal method. Lesions detected on first-pass and second-pass examination were used for adenoma detection and miss rates, respectively. The primary outcomes were adenoma and polyp detection rates.
Results: A total of 360 patients were randomized to undergo either 190-NBI or HD-WL colonoscopy. Both the adenoma and polyp detection rates were significantly higher in the 190-NBI group compared with the HD-WL group (adenoma: 48.3% vs. 34.4%, P=0.01; polyps: 61.1% vs. 48.3%, P=0.02). The mean number of polyps detected per patient was higher in the 190-NBI group (1.49% vs. 1.13, P=0.07). There was no significant difference in the adenoma miss rates between the two groups (21.8% vs. 21.2%). Multivariate analysis showed that the use of 190-NBI (odds ratio (OR) 1.85; 95% confidence interval (CI) 1.10-3.12), withdrawal time (OR 1.29; CI 1.19-1.38), patient's age (OR 1.04; CI 1.01-1.06), and male gender (OR 2.38; CI 1.42-3.99) were associated with adenoma detection.
Conclusions: 190-NBI colonoscopy was superior to the conventional HD-WL in detecting colorectal adenomas or polyps, but there was no significant difference in adenoma miss rates.