Narrow-band imaging versus high-definition endoscopy for the diagnosis of neoplasia in ulcerative colitis

Background and study aims: Controversy exists about which colonoscopic technique is most sensitive for the diagnosis of neoplasia in patients with ulcerative colitis. We compared new-generation narrow-band imaging (NBI) to high-definition endoscopy (HDE) for the detection of neoplasia and evaluated NBI for the differentiation of neoplastic from non-neoplastic mucosa.

Patients and methods: Randomized crossover trial in which patients with ulcerative colitis underwent both NBI and HDE colonoscopy in random order with at least 3 weeks between the two procedures, which were performed by different endoscopists. Lesions detected during the first examination were left in situ in order to enable detection during the second examination as well. Main outcome measures were (1) neoplasia detection, and (2) diagnostic accuracy of NBI for differentiating neoplastic from non-neoplastic mucosa by using the Kudo classification and vascular pattern intensity (VPI).

Results: Twenty-five patients were randomized to undergo HDE first and 23 to undergo NBI first. Of 16 neoplastic lesions, 11 (69 %) were detected by HDE and 13 (81 %) by NBI ( P = 0.727). Of 11 patients with neoplasia, 9 (82 %) were diagnosed by HDE and 8 (73 %) by NBI ( P = 1.0). The sensitivity, specificity, and accuracy of the Kudo classification were 76 %, 66 % and 67 %. Corresponding figures for VPI were 80 %, 72 %, and 73 %.

Conclusion: NBI does not improve the detection of neoplasia in patients with ulcerative colitis compared to HDE. In addition, NBI proves unsatisfactory for differentiating neoplastic from non-neoplastic mucosa.