Background: Mucosal dye spraying (chromoendoscopy [CE]) has been shown in controlled studies to enhance lesion detection in colitis surveillance. Narrow band imaging (NBI) potentially offers a more convenient mode of highlighting mucosal lesions. The primary objectives of this study were to compare CE and NBI in colitis surveillance with respect to lesion detection. A secondary objective was to assess the accuracy of the mucosal pit pattern (Kudo classification) with NBI in predicting mucosal histology.
Methods: Patients with colitis of 8 years or greater disease duration underwent screening colonoscopy with NBI, followed immediately by CE by 2 endoscopists blinded to each other’s results. All lesions were biopsied to confirm histology. Diagnostic yield of each modality for dysplastic lesions. Accuracy of Kudo classification by NBI for neoplasia.
Results: Forty-four participants were enrolled. One hundred forty-four colonic lesions were identified in total. Overall, CE identified more lesions than NBI (131 versus 102, P < 0.001); however, most were nondysplastic. CE detected 23 neoplastic (dysplastic or indefinite for dysplasia) lesions in 11 patients and NBI 20 lesions in 10 patients, P = 0.180. Kudo assessment by NBI had low sensitivity for dysplasia (42%) and modest accuracy (74%) for dysplasia.
Conclusions: NBI detected fewer lesions than CE in chronic colitis; however, most were not dysplastic. There was a nonsignificant trend in favor of CE for detection of dysplasia. At present, NBI cannot be recommended as an alternative to CE for dysplasia surveillance in colitis.