Virtual Chromoendoscopy for Characterization of Colorectal Polyps: Interobserver Reliability Betweeln Junior and Senior Endoscopist

Aims Endoscopic assessment of colorectal polyps’ histology based on virtual chromoendoscopy is basically allowed to “experts” only, due to a possible inter-observer variability. This study aims to assess virtual chromoendoscopy performance in colorectal polyps characterization and to evaluate the interobserver reliability between junior and senior endoscopist.

Methods A prospective study including patients who presented to our endoscopy unit from April 2018 through February 2020 for colonoscopy was conducted.

All polyps detected in white light, were examined in narrow-band imaging (NBI) or Flexible spectral imaging color enhancement (FICE) by an experienced endoscopist then resected for histological analysis. Endoscopic images were stored electronically and allocated anonymously to a junior endoscopist for evaluation. Only polyps with high quality taken photos were included.

Sensitivity, specificity and diagnostic accuracy were assessed by reference to histopathology. The evaluation of the interobserver reliability between junior and senior endoscopist was performed based on Cohen’s kappa coefficient (k) (k > 0.75: perfect agreement; k ranging from 0.4 to 0.75: moderate agreement; k < 0.4: poor agreement).

Results Sixty-four polyps were included in our study, 68.8 % of which were assessed with FICE and 31.2 % with NBI. According to the histological analysis, 39 lesions were neoplastic, versus 25 non-neoplastic lesions.

Sensitivity, specificity and diagnostic accuracy of virtual chromoendoscopy in “real-time” assessment of colorectal polyps were respectively 94.9 %, 92 %, and 94 %. Conforming to the junior endoscopist’s evaluation, sensitivity, specificity and diagnostic accuracy were respectively 82.1 %, 84 % and 82.8 %. The interobserver agreement between the junior and the senior endoscopist was moderate (k = 0.582).

Conclusions Our study demonstrated that virtual chromoendoscopy is an effective tool for optical diagnosis of colorectal lesions. However, the interobserver agreement was moderate between senior and junior endoscopist. These results suggest that endoscopists shood be trained to reduce the interobserver variability so that optical diagnosis of colorectal polyps can be generalized.

Citation: Ferchichi I, Sabbah M, Ben Farhat F et al. eP177 VIRTUAL CHROMOENDOSCOPY FOR CHARACTERIZATION OF COLORECTAL POLYPS: INTEROBSERVER RELIABILITY BETWEELN JUNIOR AND SENIOR ENDOSCOPIST. Endoscopy 2021; 53: S154.

Publication History

Article published online:
19 March 2021