Electronic Chromoendoscopy Research Articles

Assessment of Endoscopic Healing by Using Advanced Technologies Reflects Histological Healing in Ulcerative Colitis.

Several studies have reported that ulcerative colitis [UC] patients with endoscopic mucosal healing may still have histological inflammation. We investigated the relationship between mucosal healing defined by modified PICaSSO [Paddington International Virtual ChromoendoScopy ScOre], Mayo Endoscopic Score [MES] and probe-based confocal laser endomicroscopy [pCLE] with histological indices in UC. A prospective study enrolling 82 UC patients [male 66%] was conducted. High-definition colonoscopy was performed to evaluate the activity of the disease with MES assessed with High-Definition MES [HD-MES] and modified PICaSSO and targeted biopsies were taken; pCLE was then performed. Receiver operating characteristic [ROC] curves were plotted to determine the best thresholds for modified PICaSSO and pCLE scores that predicted histological healing according to the Robarts Histopathology Index [RHI] and ECAP 'Extension, Chronicity, Activity, Plus' histology score. A modified PICaSSO of ≤ 4 predicted histological healing at RHI ≤ 3, with sensitivity, specificity, accuracy and area under the ROC curve [AUROC] of 89.8%, 95.7%, 91.5% and 95.9% respectively. The sensitivity, specificity, accuracy and AUROC of HD-MES to predict histological healing by RHI were 81.4%, 95.7%, 85.4% and 92.1%, respectively. A pCLE ≤ 10 predicted histological healing with sensitivity of 94.9%, specificity of 91.3%, accuracy of 93.9% and AUROC of 96.5%. An ECAP of ≤ 10 was predicted by modified PICaSSO ≤ 4 with accuracy of 91.5% and AUROC of 95.9%. Histological healing by RHI and ECAP is accurately predicted by HD-MES and modified virtual electronic chromoendoscopy PICaSSO, endoscopic score; and the use of pCLE did not improve the accuracy any further.

P299 A prospective randomised trial comparing dye-based chromoendoscopy with electronic virtual chromoendoscopy for detection of colonic neoplastic lesions during IBD surveillance colonoscopy

Abstract Background Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer. Dye-based chromoendoscopy (CE) is the currently recommended method for the detection of dysplasia in IBD surveillance colonoscopy; the role of virtual chromoendoscopy (VCE) is not yet well defined. To compare CE with VCE using iSCAN1 digital image enhanced colonoscopy in the detection of colonic neoplastic lesions in IBD patients. Methods Randomised, single-centre trial to assess the detection rate of colonic neoplastic lesions in patients with long-standing IBD. Patients were randomised in two arms: dye-spraying CE using indigo carmine and electronic VCE using iSCAN1 digital image. Detection rates of dysplasia or any neoplastic lesion were compared by the two endoscopic techniques. Results A total of 129 patients were studied (67 by CE and 62 by VCE). Demographic and clinical characteristics were homogeneous in the two groups; 26 Crohn′s disease and 103 ulcerative colitis, 52% women, mean age 50 years, median duration of IBD 204 months, family history of colorectal cancer in 10 (8%), associated primary sclerosing cholangitis in 8 (6%), personal history of colorectal dysplastic lesions in 12 (9%), and more than 50% colonic involvement in 72 (56%). In total, 27 lesions (9 hyperplastic, 8 adenomatous and 10 low-grade dysplasia) were detected in 23 patients, without differences between CE and VCE arms (15 [22%] and 12 [19%] lesions, respectively; p = 0.98); on the other hand, neoplastic lesion (dysplasia or adenoma) detection rates was similar (12 [18%] in CE and 6 [10%] in VCE arms, p = 0.2). The duration of the withdrawal time of colonoscopy in minutes for patients in the CE group was median 14 min and in the VCE group was median 10 min (p < 0.001). Conclusion There is no statistical difference between CE and VCE using iSCAN1 in the detection rate of colonic neoplastic lesions in IBD patients. Surveillance colonoscopy with VCE (iSCAN1) spends less time than conventional CE.

OP26 The first real-life multicentre prospective validation study of the electronic chromoendoscopy score (Paddington International Virtual ChromoendoScopy ScOre) and its outcome in ulcerative colitis

Abstract Background Mucosal healing is an important goal in the treatment of ulcerative colitis (UC). The newly published PICaSSO score characterises subtle mucosal and vascular changes and defines mucosal healing. We aimed to validate in real-life the PICaSSO score and assess its ability to predict relapse. Methods Patients with UC were prospectively recruited from 11 international centres. Participating endoscopists experienced in IBD received training on PICaSSO before starting the study. The rectum and sigmoid were examined using iScan 1,2 and 3 (Pentax, Japan) and inflammatory activity was assessed using UCEIS and PICaSSO. Biopsies were taken for the histological assessment using Robarts Histological Index (RHI) and Nancy. Follow-up was obtained at 12 months. Results A total of 278 patients were recruited (Table 1). The diagnostic performance in predicting histologic healing is shown in Table 2. When using PICaSSO score of ≤3 for mucosal and vascular architecture the AUROC to predict healing by RHI is 0.79 (95% CI 0.74–0.85) and 0.73 (95% CI 0.68–0.80) respectively and when using the Nancy score the AUROC is 0.78 (95% CI 0.72–0.84) and 0.77 (0.71–0.84). A total PICaSSO score of ≤8 and UCEIS score of ≤1 predicts remission at 12 months with an AUROC of 0.73 (0.65–0.80) and 0.71 (0.64–0.79). A Kaplan–Meier curve shows a favourable survival probability without relapse with a PICASSO score of ≤8 (Figure 1). Conclusion This real-life validation study shows the PICaSSO score can predict accurately histological healing and long-term remission and can be a useful tool in the management of UC.

ESTUDO DA ACURÁCIA NA AVALIAÇÃO DOS PÓLIPOS ENTRE A COLONOSCOPIA CONVENCIONAL, CROMOSCOPIA COM NARROW-BAND IMAGING E CROMOSCOPIA COM ÍNDIGO CARMIN

Introdução: As técnicas de cromoendoscopia aperfeiçoaram a acurácia na identificação de pólipos colorretais e contribuíram para a padronização de classificações. A classificação de Kudo avaliam as criptas intestinais através de corantes, enquanto que Japan NBI Expert Team avalia principalmente o padrão vascular da mucosa intestinal por meio da cromoendoscopia eletrônica. Ambos auxiliam na acurácia diagnóstica e rastreamento de câncer colorretal. Objetivo: Comparar a eficácia da colonoscopia convencional, cromoendoscopia com índigo e colonoscopia com Narrow-Band Imaging na acurácia diagnóstica de pólipos colorretais neoplásicos e não-neoplásicos. Materiais e métodos: Foram realizadas 119 polipectomias nos pólipos colorretais pequenos em centro especializado. As imagens dos pólipos foram avaliadas por um médico endoscopista experiente, que avaliou os padrões vasculares e superfícies dos pólipos de acordo com as classificações de Kudo e Japan NBI Expert Team, conforme o método utilizado (corante, Narrow-Band Imaging ou dedução em colonoscopia convencional). Os resultados das classificações foram comparados com o exame histológico. Conclusão: A colonoscopia com índigo, a colonoscopia com NBI e a colonoscopia convencional possuem eficácia no diagnóstico endoscópico, sendo a cromoscopia com índigo a de maior acurácia. Todavia, o diagnóstico endoscópico não deve ser exclusivo, sendo complementado pela avaliação histológica.

Impact of Electronic Chromoendoscopy on Adenoma Miss Rates During Colonoscopy: A Systematic Review and Meta-analysis

The impact of virtual chromoendoscopy such as narrow-band imaging, Fujinon intelligent chromoendoscopy, blue-light imaging, linked-color imaging, and i-SCAN on adenoma detection rate has been variable. However, adenoma miss rate (another measure suggested as a quality indicator) of electronic chromoendoscopy modalities has not been systematically evaluated. This study aimed to perform a systematic review and meta-analysis to examine the adenoma miss rate of white-light endoscopy compared with electronic chromoendoscopy. Medline, Embase, Scopus, Web of Knowledge, and Cochrane were the data sources for this study. The studies selected were tandem randomized controlled trials of electronic chromoendoscopy modalities compared with white-light endoscopy. Electronic chromoendoscopy compared with white light endoscopy was used to measure the adenoma miss rate. Primary outcome was the pooled adenoma miss rate of electronic chromoendoscopy techniques compared with white-light endoscopy. Secondary outcomes were subgroup analysis, adenoma size analysis, and adenoma detection rate. A total of 3507 patients were evaluated from 7 eligible tandem randomized control trials. A total of 1423 patients had white-light endoscopy as the first of the tandem examinations. The rest of the patients had electronic chromoendoscopy as the first of the tandem examination (narrow-band imaging, 988 patients; Fujinon intelligent chromoendoscopy, 728 patients; i-SCAN, 233 patients; blue-light imaging, 64 patients; and linked-color imaging, 71 patients). The pooled adenoma miss rate for electronic chromoendoscopy was not different than white-light endoscopy (17.9% vs 21%; OR, 0.72 (0.67-1.11); I 67%; p = 0.13). When only narrow-band imaging, blue-light imaging, and linked-color imaging were considered, the pooled rate was statistically significant (OR, 0.60 (0.37-0.98); p = 0.04). The pooled adenoma detection rate was not statistically different with electronic chromoendoscopy than white-light endoscopy (OR, 1.02 (0.88-1.19); p = 0.78). The small number of studies to assess the impact of each modality limited stratified conclusions. Electronic chromoendoscopy is not associated with a significant reduction in adenoma miss rate compared with white-light colonoscopy.

Colonoscopy technologies for diagnostics and drug delivery

AbstractWith a global increase of colorectal cancer, inflammatory bowel disease and other colon‐related illnesses, advanced technologies are needed for imaging of the colon and localized drug delivery. Optical colonoscopy is the gold standard for imaging of the colon. However, existing colonoscopy approaches have a high adenoma misdiagnosis rate, which can be lethal for patients. This article reviews the emergence of virtual colonoscopy, dye‐based chromoendoscopy, electronic chromoendoscopy and capsule endoscopy in diagnosis. Flexible spectral imaging colour enhancement, the use of second‐generation capsule endoscopy and i‐scan were described. Moreover, a drug delivery system using capsule endoscopy was discussed. Finally, this review includes market analyses of commercial products, clinical trials and future prospects of colonoscopy devices.

Sa1723 – Mucosal Healing Defined by Advanced Electronic Chromoendoscopy Picasso (Paddington International Virtual Chromoendoscopy Score) and Probe Confocal Laser Endomicroscopy Accurately Predict Histological Healing of Active Inflammation But Not Chronic Changes

Sa1723 – Mucosal Healing Defined by Advanced Electronic Chromoendoscopy Picasso (Paddington International Virtual Chromoendoscopy Score) and Probe Confocal Laser Endomicroscopy Accurately Predict Histological Healing of Active Inflammation But Not Chronic Changes

P254 Re-defining the concept of endoscopic and histological healing by using electronic virtual chromoendoscopy and probe confocal endomicroscopy in ulcerative colitis

P254 Re-defining the concept of endoscopic and histological healing by using electronic virtual chromoendoscopy and probe confocal endomicroscopy in ulcerative colitis

P164 Mucosal healing (MH) assessed with PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) and probe Confocal Laser Endomicroscopy (pCLE) do not reflect histological normalisation using the ECAP (Extent Chronicity Activity Plus) score

Ulcerative colitis (UC) is a chronic disease that requires long-term therapy and the achievement of mucosal healing (MH) is the target of the treatment. The new histological score ECAP (Extent Chronicity Activity Plus) has been developed to detect minimal chronic changes. The electronic Virtual Chromoendoscopy Endoscopy (VCE) score PICaSSO (Paddington International Virtual ChromoendoScopy ScOre)1 and probe Confocal Laser Endomicroscopy (pCLE) scores reflect acute histological changes (Robarts Histological Index-[RHI]) well,2 but it is unknown whether these may reflect chronic histological changes. This is a prospective study involving 82 UC patients at the Endoscopy Unit, Foothills Medical Center, University of Calgary, Canada. For each patient, clinical data including follow-up up to 12 months, endoscopic scores (Mayo endoscopic score, PiCasso and pCLE score) and histological ECAP score were determined. The details of ECAP score has already been published.1 Receiver-operating characteristics (ROC) curves were plotted to estimate the cut-offs for PICaSSO and pCLE scores best predicting the MH determined by histological ECAP score. 70 patients (85.4%) were in clinical remission. We have compared the endoscopic scores (MES, PICaSSO, and pCLE) with histological healing defined by ECAP ≤ 4. Only 14 patients (28.6%) with Mayo 0 had ECAP ≤ 4. From the ROC curves, the best cut-off for PICaSSO score was 4, with sensitivity and specificity of 88.9% (95% CI 64.3%-98.6%) and 40.6% (95% CI 28.5%-53.6%), respectively with an area under ROC curve (AUROC) of 69.9% (95% CI 57.2%-82.6%). At this value, out of 54 patients with PICaSSO ≤ 4, only 16 (29.6%) have ECAP ≤ 4. The ROC curves for pCLE showed that the best cut-off point to detect MH (ECAP ≤ 4) was 11 with sensitivity of 94.4% (95% CI 72.7–99.9%) specificity of 31.3% (95% CI 20.2%-44.1%) with AUROC of 71.4% (95% CI 57.9%-84.8%). At this value of pCLE, 17 (27.9%) patient amongst 61 had ECAP ≤ 4. ROC curve for PICaSSO in the prediction of mucosal healing (ECAP ≤ 4) During the follow-up period, 8.06% of patients had a relapse: 80% had PICaSSO score ≤ 4, 80% had pCLE ≤ 11, and only one relapse 20% had ECAP ≤ 4. According our results, the endoscopic scores (PICaSSO and pCLE) are not able to predict histological healing calculated using ECAP (both chronic and acute changes) at the value ≤ 4. An ECAP score ≤4 may however predict stable mucosal healing with few relapses over 12 months.

2017 David Sun Lecture: Screening and Surveillance of Barrett's Esophagus: Where Are We Now and What Does the Future Hold?

Barrett's esophagus and esophageal adenocarcinoma continue to present considerable management challenges in the Western world. Despite our best efforts to date, the prognosis of advanced esophageal adenocarcinoma remains poor and far too many individuals with esophageal adenocarcinoma have not had a prior endoscopy to detect Barrett's esophagus. As such, current strategies of screening for Barrett's esophagus and subsequent surveillance need to be further optimized. Screening today is limited to high definition white light endoscopy in high-risk patient populations and as such has multiple limitations. However, a variety of exciting new techniques including risk prediction tools, tethered capsule endomicroscopy, a cytology sponge, breath testing for exhaled volatile organic compounds, and assessment of the oral microbiome are now under study in an effort to develop less expensive population-based screening methods. Similarly, endoscopic surveillance, as currently practiced has a variety of limitations. Inexpensive readily available adjuncts are already available to optimize surveillance including increased inspection time in an effort to detect mucosal or vascular abnormalities, special attention to the right hemisphere of the esophagus, and utilization of narrow band imaging or other electronic chromoendoscopy techniques. To improve endoscopic surveillance, a variety of new paradigms are under study including wide area trans-epithelial sampling, advanced endoscopic imaging, molecular imaging, clinical risk stratification and utilization of biomarkers of increased risk. However, progress will be challenging due to the complexity of esophageal cancer biology and the rarity of progression to cancer among patients with nondysplastic Barrett's epithelium.

Post-polypectomy surveillance interval based on flexible spectral color imaging enhancement (FICE) with magnifying zoom imaging for optical biopsy.

Abstract Background and study aims Post-polypectomy surveillance interval (SI) is determined based on the number, size, and histology of colorectal polyps. Electronic chromoendoscopy in association with magnifying imaging colonoscopy allows “in vivo” polyp histology prediction. Colorectal polyps ≤ 5 mm can be resected and discarded without pathologic assessment if the endoscopic technology when used with high confidence provides ≥ 90 % agreement between the post-polypectomy SI and the SI based on pathological assessment. The aim of this study was to evaluate the agreement between the post-polypectomy SI based on flexible spectral color imaging enhancement (FICE) chromoendoscopy in association with magnified imaging and the pathology-based SI. Patients and methods Each diagnosed colorectal polyp received a histology prediction (neoplastic or non-neoplastic) based on the FICE capillary-vessel pattern classification. Each prediction was classified as high or low confidence. SI based on the FICE prediction was compared to the pathology-based SI recommendation according to the US Multi-Society Task Force on Colorectal Cancer guideline. Sensitivity, specificity and accuracy of FICE in diagnosing neoplastic lesions were compared with the pathology assessment. Interobserver and intraobserver agreement for FICE-based SI predictions was evaluated using the kappa coefficient. Results A total of 267 polyps had histology prediction assessed with high confidence in 136 patients. Sensitivity of FICE was 98.7 % (95 % CI: 93.5 – 99.3) and specificity was 62.5 % (95 % CI: 43.6 – 78.9). Prediction accuracy was 94.4 % (95 % CI: 88.6 – 96 – 1) in differentiating between neoplastic and non-neoplastic lesions. Therefore, magnifying FICE colonoscopy-based SI recommendation was consistent with pathological assessment in 88.3 % of general cases (95 % CI: 82.1 – 92.6) and in 89.7 % (95 % CI: 83 – 94.5) of the high-confidence evaluation cases. The intraobserver agreement value for FICE-based SI predictions was 0.87 (high-confidence evaluations), and the interobserver agreement values were 0.78 (high- and low-confidence evaluations) and 0.82 (high-confidence evaluations) (95 % CI: 0.79 – 0.95). Conclusions FICE-based SI demonstrated 89.7 % concordance with the pathology-based SI.

Effect of I-scan Electronic Chromoendoscopy on Detection of Adenomas During Colonoscopy

I-scan is an electronic chromoendoscopy technology that improves resolution of epithelial and mucosal surfaces and vessels. We performed a randomized controlled trial to compare detection of adenomas by i-scan vs standard high-definition white-light (HDWL) colonoscopy. From February 1 through December 31, 2017, 740 outpatients (50-75 years old) undergoing screening and surveillance for colorectal neoplasia were randomly assigned to groups that received colonoscopies with i-scan 1 (surface and contrast enhancement) or HDWL. When lesions and polyps were detected, endoscopists could switch between i-scan 1 and HDWL imaging to confirm their finding; polyps were collected and analyzed by histology. The primary outcome was adenoma detection rate (ADR, proportion of subjects with at least 1 adenoma of any size); secondary outcomes included detection of sessile serrated polyps and neoplasias, along with location, size, and morphology of polyps. We performed intent to treat and per-protocol analyses (on 357 patients evaluated by i-scan and 358 evaluated by HDWL colonoscopy) to assess the primary and secondary outcomes. There were no differences in baseline characteristics between the groups. In the intent to treat analysis, the ADR was significantly higher in the i-scan 1 group (47.2%) than in the HDWL colonoscopy group (37.7%) (P = .01). In the per-protocol analysis, the ADR in the i-scan 1 group (47.6%) was also significantly higher than in the HDWL group (37.2%) (P = .005), but this effect was not consistent among all endoscopists. There was no difference between groups in detection of sessile serrated polyps. However, the rate of neoplasia detection was significantly higher in the i-scan 1 group (56.4%) than in the than the HDWL group (46.1%) (P=.005). In secondary analyses, the increase in ADR was associated with improved detection of diminutive flat adenomas in the right colon. In a prospective randomized trial, higher proportions of patients with adenomas were identified in a group that underwent colonoscopy with i-scan 1 than in a group evaluated by HDWL colonoscopy. This effect was mainly due to improved detection of diminutive, flat right sided adenomas. I-scan 1 technology may benefit some endoscopists. ClinicalTrials.gov no: NCT02811419.

The Paddington International Virtual Chromoendoscopy Score in ulcerative colitis exhibits very good inter-rater agreement after computerized module training: a multicenter study across academic and community practice (with video)

Electronic virtual chromoendoscopy (EVC) can demonstrate ongoing disease activity in ulcerative colitis (UC), even when Mayo subscores suggest healing. However, applicability of EVC technology outside the expert setting has yet to be determined. Fifteen participants across 5 centers reviewed a computerized training module outlining high-definition and EVC (iScan) colonoscopy modes. Interobserver agreement was then tested (Mayo score, Ulcerative Colitis Endoscopic Index of Severity [UCEIS], and the Paddington International Virtual Chromoendoscopy Score [PICaSSO] for UC), using a colonoscopy video library (30 cases reviewed pretraining and 30 post-training). Knowledge sustainability was retested in a second round (42 cases; 9/15 participants), 6 months after training provision. Pretraining intraclass correlation coefficients (ICC) were good for the Mayo endoscopic subscore (ICC, .775), UCEIS scoring erosions/ulcers (ICC, .770), and UCEIS overall (ICC, .786) and for mucosal (ICC, .754) and vascular components of PICaSSO (ICC, .622). For the vascular components of UCEIS, agreement was only moderate (ICC, .429) and did not enhance post-training (ICC, .417); conversely, use of PICaSSO improved post-training (mucosal ICC, .848; vascular, .746). Histologic correlation using the New York Mt. Sinai System was strong for both PICaSSO components (Spearman's ρ for mucosal: .925; vascular, .873; P< .001 for both). Moreover, accuracy in specifically discriminating quiescent from mild histologic strata was strongest for PICaSSO (area under the receiver operating characteristic curve [AUROC] for mucosal, .781; vascular, .715) compared with Mayo (AUROC, .708) and UCEIS (AUROC for UCEIS overall, .705; vascular, .562; bleeding, .645; erosions/ulcers, .696). Inter-rater reliability for PICaSSO was sustained by round 2 participants (round 1 and 2 ICC for mucosal, .873 and .869, respectively; vascular, .715 and .783, respectively), together with histologic correlation (ρ mucosal, .934; vascular, .938; P< .001 for both). PICaSSO demonstrates good interobserver agreement across all levels of experience, providing excellent correlation with histology. Given the ability to discriminate subtle endoscopic features, PICaSSO may be applied to refine stratified treatment paradigms for UC patients.

A Randomized Trial Comparing High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy for Detection of Colonic Neoplastic Lesions During IBD Surveillance Colonoscopy.

Dye spraying chromoendoscopy (DCE) is recommended for the detection of colonic neoplastic lesions in inflammatory bowel disease (IBD). The majority of neoplastic lesions are visible endoscopically and therefore targeted biopsies are appropriate for surveillance colonoscopy. To compare three different techniques for surveillance colonoscopy to detect colonic neoplastic lesions in IBD patients: high definition (HD), (DCE), or virtual chromoendoscopy (VCE) using iSCAN image enhanced colonoscopy. A randomized non-inferiority trial was conducted to determine the detection rates of neoplastic lesions in IBD patients with longstanding colitis. Patients with inactive disease were enrolled into three arms of the study. Endoscopic neoplastic lesions were classified by the Paris classification and Kudo pit pattern, then histologically classified by the Vienna classification. A total of 270 patients (55% men; age range 20-77 years, median age 49 years) were assessed by HD (n=90), VCE (n=90), or DCE (n=90). Neoplastic lesion detection rates in the VCE arm was non-inferior to the DCE arm. HD was non-inferior to either DCE or VCE for detection of all neoplastic lesions. In the lesions detected, location at right colon and the Kudo pit pattern were predictive of neoplastic lesions (OR 6.52 (1.98-22.5 and OR 21.50 (8.65-60.10), respectively). In this randomized trial, VCE or HD-WLE is not inferior to dye spraying colonoscopy for detection of colonic neoplastic lesions during surveillance colonoscopy. In fact, in this study HD-WLE alone was sufficient for detection of dysplasia, adenocarcinoma or all neoplastic lesions.

BASIC (BLI Adenoma Serrated International Classification) classification for colorectal polyp characterization with blue light imaging.

Advanced endoscopic imaging has revolutionized the characterization of lesions during colonoscopy. The aim of this study was to create a new classification for differentiating subcentimetric hyperplastic and adenomatous polyps, and deeply invasive malignant lesions using blue-light imaging (BLI) with high definition, with and without optical magnification, as well as to assess its interobserver concordance. A video library consisting of 48 videos/still images (with/without optical magnification) from 24 histologically verified polyps/cancer with BLI was prospectively created. In the first step, seven endoscopists with experience in electronic chromoendoscopy reviewed 12 BLI videos/still images with/without magnification representative of the different histotypes, and individually identified possible descriptors. In the second step, these descriptors were categorized and summarized with a modified Delphi methodology. In the third step, the seven endoscopists independently reviewed the remaining 36 videos/still images with/without optical magnification, and the interobserver agreement for the new descriptors was assessed. The interobserver agreement between endoscopists was assessed using Gwet's AC1. By reviewing the initial 12 videos/still images, 43 descriptors were proposed. By a modified Delphi process, the endoscopists eventually agreed on summarizing 12 descriptors into three main domains. The main domains identified were: polyp surface (mucus, yes/no; regular/irregular; [pseudo]depressed, yes/no), pit appearance (featureless, yes/no; round/nonround with/without dark spots; homogeneous/heterogeneous distribution with/without focal loss), and vessels (present/absent, lacy, pericryptal, irregular). Interobserver agreement for the polyp surface domain appeared to be almost perfect for mucus (AC1 0.92 with and 0.88 without optical magnification), substantial for the regular/irregular surface (AC1 0.67 with and 0.66 without optical magnification). For the pit appearance domain, interobserver agreement was good for featureless (AC1 0.9 with and 0.8 without optical magnification), and round/nonround (AC1 0.77 with and 0.69 without optical magnification) descriptors, but less consistent for the homogeneity of distribution (AC1 with/without optical magnification 0.58). Agreement was almost perfect for the vessel domain (AC1 0.81 - 0.85). The new BASIC classification takes into account both morphological features of the polyp, as well as crypt and vessel characteristics. A high concordance among the observers was shown for most of the summarized descriptors. Optical magnification had a beneficial effect in terms of interobserver agreement for most of the descriptors.

Sa1049 The Virtual Electronic Chromoendoscopy (Vec) Score in Ulcerative Colitis Exhibits Very Good Inter-Rater Agreement in Scoring Mucosal and Vascular Changes After Computerised Module Training: A Study Across Academic and Community Practice

Sa1049 The Virtual Electronic Chromoendoscopy (Vec) Score in Ulcerative Colitis Exhibits Very Good Inter-Rater Agreement in Scoring Mucosal and Vascular Changes After Computerised Module Training: A Study Across Academic and Community Practice

Mo2070 - Initial Experience of Electronic Chromoendoscopy for Detection of Early Gastric Cancer in Northern Mexico

Mo2070 - Initial Experience of Electronic Chromoendoscopy for Detection of Early Gastric Cancer in Northern Mexico

Development and reliability of the new endoscopic virtual chromoendoscopy score: the PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis

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. 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. 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%). 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.

Beyond white light: optical enhancement in conjunction with magnification colonoscopy for the assessment of mucosal healing in ulcerative colitis.

Background and study aim The I-SCAN optical enhancement (OE) system with magnification is a recently introduced combination of optical and digital electronic virtual chromoendoscopy, which enhances mucosal and vascular details. The aim of this pilot study was to investigate the use of I-SCAN OE in the assessment of inflammatory changes in ulcerative colitis (UC). Patients and methods A total of 41 consecutive patients with UC and 9 control patients were examined by I-SCAN OE (Pentax Medical, Tokyo, Japan). Targeted biopsies of the imaged areas were obtained. A new optical enhancement score focusing on mucosal and vascular changes was developed. The diagnostic accuracy of I-SCAN OE was calculated against histology using two UC histological scores - Robarts Histopathology Index (RHI) and ECAP (Extent, Chronicity, Activity, Plus additional findings). Results The overall I-SCAN OE score correlated with ECAP (r = 0.70; P < 0.001). The accuracy of the overall I-SCAN OE score to detect abnormalities by ECAP was 80 % (sensitivity 78 %, specificity 100 %). I-SCAN OE vascular and mucosal scores correlated with ECAP (r = 0.65 and 0.71, respectively; P < 0.001). The correlation between overall I-SCAN OE score and RHI was r = 0.61 (P < 0.01), and the accuracy to detect abnormalities by RHI was 68 % (sensitivity 78 %, specificity 50 %). The majority of patients with Mayo 0 had abnormalities on I-SCAN OE. Conclusion In UC, the new I-SCAN OE technology accurately identified mucosal inflammation, and correlated well with histological scores of chronic and acute changes.

DOP068 The virtual electronic chromoendoscopy score in ulcerative colitis exhibits very good inter-rater agreement in scoring mucosal and vascular changes after computerised module training: a study across academic and community practice

Background: Mucosal healing is the desired therapeutic endpoint for clinical trials in ulcerative colitis (UC). However, conventional white light endoscopy may fall short of capturing the full spectrum of inflammatory change; and virtual electronic chromoendoscopy (VEC) can show ongoing disease activity even when Mayo scores suggest healing (Iacucci et al. Endoscopy 2015). Applicability of VEC scoring requires determination outside the expert setting; thus, our aim was to provide external validation among trainees, consultant gastroenterologists and colorectal surgeons, practicing across six general and specialist centres. Methods: 15 participants reviewed a computerised training module outlining HD and i-Scan modes. Anchor points for the VEC score indicated mucosal changes (crypt distortion, 0 [A–C]; microerosions, I [1–3]; erosions, II [1–3]; and ulceration, III [1–3]) and vascular alterations (non-dilated vessels, 0 [A–C]; dilated/crowded vessels, I [1–3]; mucosal bleeding, II [1–3]; and intraluminal bleeding, III [1–3]). Performance accuracy was tested using a video library pre-/post-training (n=30). Agreement between raters was tested for the Mayo score, UCEIS and VEC score, and results correlated with histology (New York Mount Sinai system; Harpaz et al.). Results: The inter-rater agreement was very good for the Mayo score, UCEIS scoring erosions/ulcers and overall, and for VEC scoring mucosal patterns in both modules (Table 1). For the vascular components of UCEIS agreement was only moderate, and did not improve post-training; unlike the agreement for VEC vascular patterns which improved significantly to very good. Correlation between histology and VEC score was highly significant for mucosal and vascular scoring (Spearman's ρ: 0.910, p<0.001; and 0.907, p<0.001; respectively, Figure 1). This was superior to the Mayo score (0.876, p<0.001) and UCEIS (0.887, p<0.001). Table 1. ICCs are from a two-way random model with absolute agreement, and are for single measures. All values are significant at a p<0.001. Figure 1. Correlation between the EVC score and histology in ulcerative colitis. Average score per video per participant for each category are presented (post-training). Conclusions: The VEC score demonstrates very good inter-observer agreement across all levels of experience and provides excellent correlation with histology. Unlike UCEIS, the VEC score does not have subjective elements (e.g. mucosal erythema, incidental/contact friability) and may better delineate vascular changes due to filter technology. Given the ability to define subtle endoscopic features, VEC may be applied to further stratify treatment paradigms for patients with UC.