Digital Single-operator Cholangioscopy (DSOC) Improves Interobserver Agreement (IOA) and Accuracy for Evaluation of Indeterminate Biliary Strictures

Abstract

Background: Visual characteristics seen during digital single-operator cholangioscopy (DSOC) have not been validated. The aim of this 2-phase study was to define terminology by consensus for the visual diagnosis of biliary lesions to develop a model for optimization of the diagnostic performance of DSOC. Materials and Methods:In phase 1 (criteria identification), video-cholangioscopy clips were reviewed by 12 expert biliary endoscopists, who were blinded to the final diagnosis. Visual criteria were consolidated into the following categories: (1) stricture, (2) lesion, (3) mucosal features, (4) papillary projections, (5) ulceration, (6) abnormal vessels, (7) scarring, (8) pronounced pit pattern. During the second phase (validation), 14 expert endoscopists reviewed DSOC (SpyGlass DS, Boston Scientific) clips using the 8 criteria to assess interobserver agreement (IOA) rate.Results: In phase 1, consensus for visual findings were categorized into 8 criteria titled the "Monaco Classification." The frequency of criteria were: (1) presence of stricture-75%, (2) presence of lesion type-55%, (3) mucosal features-55%, (4) papillary projections-45%, (5) ulceration-42.5%, (6) abnormal vessels-10%, (7) scarring-40%, and (8) pronounced pit pattern-10%. The accuracy on final diagnosis based on visual impression alone was 70%. In phase 2, the IOA rate using Monaco Classification criteria ranged from slight to fair. The presumptive diagnosis IOA was fair (κ = 0.31, SE = 0.02), and overall diagnostic accuracy was 70%. Conclusions:The Monaco classification identifies 8 visual criteria for biliary lesions on single-operator digital cholangioscopy. Using the criteria, the IOA and diagnostic accuracy rate of DSOC is improved compared with prior studies.

Clinical practice patterns in indirect peroral cholangiopancreatoscopy: outcome of a European survey

“…According to this survey, the evaluation of biliary strictures was one of the main indications for cholangioscopy. Previous studies have shown very good results regarding the diagnostic accuracy of visual characteristics for determining the etiology of strictures, but considerable interobserver variation exists among endoscopists 4 5 . Morphological features of malignant and inflammatory disease may overlap significantly and not be exclusive or clearly discriminative, even for experienced endoscopists.…”

Efficacy and Safety of Digital Single-Operator Cholangioscopy in the Diagnosis of Indeterminate Biliary Strictures by Targeted Biopsies: A Systematic Review and Meta-Analysis

“…Recently, the Monaco classification has been reported to address this problem. In this study [31], the visual standards were merged into eight categories: stricture, lesion, mucosal features, papillary projections, ulceration, abnormal vessels, scarring, and pronounced pit pattern. The IOA and diagnostic accuracy of DSOC significantly improved with this classification when compared to previous studies.…”

Consensus guidelines on the role of cholangioscopy to diagnose indeterminate biliary stricture

“…This was pathologically correlated with the subepithelial spreading of fibrotic tumor which resulted in greater difficulty in acquiring diagnostic tissue when compared with the other criteria (37). Notably, the subsequent validation studies demonstrated that tumor vessels, papillary projection, nodules, and infiltrative lesions had fair to moderate inter-observer agreement with Kappa value of 0.12-0.26, 0.43-0.54, 0.26, and 0.34, respectively (Table 5) (39,40). Nevertheless, the consensus panelists agreed these four criteria are important and should be assessed when visual impression is required for biliary malignancy diagnosis.…”