Development and reliability of the new endoscopic virtual chromoendoscopy score: the PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis.
OBJECTIVE
Endoscopic inflammation and healing are important therapeutic endpoints in ulcerative colitis (UC). We developed and validated a new electronic virtual chromoendoscopy (EVC) score that could reflect the full spectrum of mucosal and vascular changes including mucosal healing in UC.


METHODS
Eight participants reviewed a 60-minute training module outlining 3 different i-SCAN modes demonstrating the entire spectrum of inflammatory mucosal and vascular changes in UC. Performance characteristics in endoscopic scoring and predicting the histologic inflammation with EVC (i-SCAN) by using 20 video clips before (pre-test) and after (post-test) were evaluated. Exploratory univariate factor analysis was performed on Paddington International Virtual Chromoendoscopy Score (PICaSSO) covariates for mucosal and vascular score separately. Subsequently, a proportional odds logistic regression model for the prediction of histologic scores was analyzed.


RESULTS
The interobserver agreement for Mayo endoscopic score in the pre-test (κ = .85; 95% CI, .78-.90) and the post-test (κ = .85; 95% CI, .77-.90) evaluation were very good. This was also true for the Ulcerative Colitis Endoscopic Index of Severity in the pre-test and post-test score interobserver agreement (κ = .86; 95% CI, .77-.92; and κ = .84; 95% CI, .75-.91, respectively). The interobserver agreement of the PICaSSO endoscopic score was very good in the pre-test and post-test evaluations (κ = .92; 95% CI, .87-.96; and κ = .89; 95% CI, .84-.94, respectively). The accuracy of the overall PICaSSO in assessing histologic abnormalities and inflammation by Harpaz score was 57% (95% CI, 48%-65%), by Robarts Histological Index 72% (95% CI, 64%-79%), and by the extent, chronicity, activity, plus system (full spectrum of histologic changes) 83% (95% CI, 76%-88%).


CONCLUSIONS
The EVC score "PICaSSO" showed very good interobserver agreement. The new EVC score may be used to define the endoscopic findings of mucosal and vascular healing in UC and reflected the full spectrum of histologic changes.
Division of Gastroenterology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Division of Gastroenterology, Biomedical Research Centre and Institute of Translational Medicine, University of Birmingham, Birmingham, United Kingdom.
Marietta
M
Iacucci
Division of Gastroenterology, University of Torino, Torino, Italy.
Marco
M
Daperno
Division of Gastroenterology, Johns Hopkins Hospital, Baltimore, Maryland, USA.
Mark
M
Lazarev
Division of Gastroenterology, Morristown Medical Center, Atlantic Health System, Morristown, New Jersey, USA.
Razvan
R
Arsenascu
Department of Biomedical Sciences for the Health Division of Gastroenterology IRCCS Policlinico San Donato, University of Milan, Milan, Italy.
Gian Eugenio
GE
Tontini
Division of Gastroenterology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Oluseyi
O
Akinola
Department of Pathology, University of Calgary, Calgary, Alberta, Canada.
Xianyong Sean
XS
Gui
Institute of Pathology, ASST Spedali Civili, Brescia, Italy.
Vincenzo
V
Villanacci
Division of Gastroenterology, University Klinikum, Tubingen, Germany.
Martin
M
Goetz
Department of Community Health Sciences, Clinical Research Unit, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Mark
M
Lowerison
Department of Community Health Sciences, Clinical Research Unit, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Brendan Cord
BC
Lethebe
Department of Biomedical Sciences for the Health Division of Gastroenterology IRCCS Policlinico San Donato, University of Milan, Milan, Italy.
Maurizio
M
Vecchi
Interventional Endoscopy Center, I. Medizinische Klinik und Poliklinik, University Hospital, Mainz, Germany.
Helmut
H
Neumann
Division of Gastroenterology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Division of Gastroenterology, Biomedical Research Centre and Institute of Translational Medicine, University of Birmingham, Birmingham, United Kingdom.
Subrata
S
Ghosh
Department of Gastroenterology and Hepatology, University Hospitals Leuven, KU Leuven, Leuven, Belgium.
Raf
R
Bisschops
Division of Gastroenterology, Director of Internal Medicine II, HSK Hospital, Wiesbaden, Germany.
Ralf
R
Kiesslich
D001808:Blood Vessels / Q000000981:diagnostic imaging; D003093:Colitis, Ulcerative / Q000000981:diagnostic imaging* / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D003116:Color; D006801:Humans; D007413:Intestinal Mucosa / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014741:Video Recording; D014945:Wound Healing