Diagnostic Accuracy Of Applying The Wasp Classification To Blue Light Imaging And Linked Color Imaging For Real-Time Colorectal Polyp Charaterisation

Aims The Workgroup SerrAted polypS and Polyposis (WASP) classification for endoscopic characterisation of colorectal polyps has been validated using Narrow Band imaging (NBI) technology, leaving uncertainty regarding its applicability to other imaging techniques. The aim of this study was to address the diagnostic accuracy of real-time polyp characterisation applying the WASP classification to Blue Light imaging (BLI), Linked Color imaging (LCI) and high-definition white light endoscopy (HD-WE).

Methods This is a post-hoc analysis of a prospective study in which 22 experienced endoscopists (>2,000 colonoscopies) from eight international centres participated. Lesions were characterised using the WASP classification, including a high- or low-confidence statement. Endoscopists were familiar with the WASP classification, but were not formally trained for the purpose of this study. Endoscopists could use LCI, BLI and HD-WLE to assess each lesion. Histopathology was reference standard. For the calculation of the diagnostic accuracies adenomas, sessile serrated lesions and hyperplastic polyps were considered different histological subtypes.

Results In 332 patients, 341 lesions were detected. For the analysis, 269 histologically confirmed adenomas (n = 165), sessile serrated lesions (n = 27) and hyperplastic polyps (n = 77) were included for which an optical diagnosis was recorded. Polyp characterisation was performed with high confidence in 82.9 %. The overall accuracy for polyp characterisation was 75.1 % (95 % confidence interval [CI] 69.5-80.1 %), which was 78.0 % (95 % confidence interval [CI] 72.0-83.2 %) for high confidence assignments only. Adenomas were characterised with 80.0 % (95 % CI 73.1-85.8 %) accuracy and increased to 84.9 % (95 % CI 77.8-90.4 %) for high-confidence predictions. The accuracy for diminutive polyp characterisation was 74.7 % (95 % CI 68.4-80.3 %), compared with an accuracy of 78.2 % (95 % CI 71.4-84.0 %) for high-confidence assignments.

Conclusions This is the first study to determine diagnostic accuracies for colorectal polyp characterisation, when performed by expert endoscopists using the WASP classification with BLI, LCI and HD-WLE (NCT03344289).

Citation: Houwen BBSL, Vleugels JLA, Pellisé M et al. OP186 DIAGNOSTIC ACCURACY OF APPLYING THE WASP CLASSIFICATION TO BLUE LIGHT IMAGING AND LINKED COLOR IMAGING FOR REAL-TIME COLORECTAL POLYP CHARATERISATION. Endoscopy 2021; 53: S77.

Publication History

Article published online:
19 March 2021