Narrow-band imaging as an alternative to chromoendoscopy for the detection of dysplasia in long-standing inflammatory bowel disease: a prospective, randomized, crossover study

Background: Narrow-band imaging (NBI) is a novel technique that may represent an alternative method to chromoendoscopy (CE) for the detection of colitis-associated intraepithelial neoplasia (IN) in patients with long-standing inflammatory bowel disease (IBD). Objective: To compare NBI with CE for the detection of IN. Design: Prospective, randomized, crossover study. Setting: Academic hospital. Patients: Patients with clinically inactive colonic IBD (>= 8 years). Intervention: Patients underwent both CE and NBI in randomized order. Targeted biopsy specimens from abnormal areas were obtained. Pathological examination was regarded as the reference standard. Main Outcome Measurements: Number of false-positive and true-positive lesions in patients undergoing CE and NBI were compared as well as the proportion of patients with missed IN lesions. Results: Eighty patients were screened, of whom 20 were excluded. Mean +/- standard deviation withdrawal time for CE was significantly longer than that for NBI (26.87 +/- 9.89 minutes vs 15.74 +/- 5.62 minutes, P < .01). Thirteen patients had at least 1 IN lesion on 1 of the examinations. In the per-lesion analysis, NBI resulted in a significantly inferior false-positive biopsy rate (P = .001) and a similar true-positive rate. The percentage of missed IN lesions and patients was superior with NBI, albeit without reaching statistical significance. Limitations: Lesions were sampled immediately after detection, which precluded the possibility of paired analysis. Conclusions: NBI appears to be a less time-consuming and equally effective alternative to CE for the detection of IN. However, given the NBI lesion and patient miss rates, it cannot be recommended as the standard technique. (Gastrointest Endosc 2011;74:840-8.)