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

Abstract

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.