EVALUATION OF INTEROBSERVER AGREEMENT OF DIGITAL SINGLE-OPERATOR CHOLANGIOSCOPY FOR INDETERMINATE BILIARY STRICTURES

Aims Visual findings during digital single-operator cholangioscopy (DSOC) still plays a major role in diagnosis of indeterminate biliary strictures (IDBS). A universally accepted classification is lacking. The Monaco Classification was recently proposed to overcome this limitation. The aim of this study was to evaluate efficacy and reproducibility of this classification.

Methods Twenty-second DSOC clips were retrospectively reviewed by 6 experts and 6 trainees with no expertise in biliary endoscopy and classified according to the Monaco Classification. Investigators were all blinded to the final diagnosis. Final diagnosis was based on histological evaluation of the surgical specimen when available or a clinical diagnosis after a follow-up of at least 6 months.

Results Twenty-nine clips were reviewed. Overall accuracy of DSOC visual finding was 73.6% and 64.4% for experts and trainees, respectively. Results of interobserver agreement are shown in [Table 1].

Table 1 Interobserver agreement between experts and trainees for DSOC clips of indeterminate biliary strictures using Monaco Classifi cation.

	kappa	agreement	p-value
Stricture	0.531	69	<0.001
Lesion	0.564	69	<0.001
Mucosal features	0.728	86.2	<0.001
Papillary projections	0.609	72.4	<0.001
Ulceration	0.562	72.4	<0.001
Abnormal vessels	0.571	72.4	<0.001
Scarring	0.319	69	0.003
Pronounced pit pattern	0.037	28.4	0.355
Final diagnosis	0.871	93.1	<0.001

Conclusions Despite the moderate overall accuracy compared to final diagnosis, the Monaco Classification showed good interobserver agreement. Further studies are needed to confirm its reproducibility in current clinical practice.

Publication History

Article published online:
14 April 2022