High-definition White Light Endoscopy Research Articles

From random to precise: updated colon cancer screening and surveillance for inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) are at increased risk of developing colorectal cancer (CRC). The pathogenesis of CRC in IBD differs from sporadic cancer, with the burden of inflammation being an important contributing factor. Other risk factors for developing CRC in patients with Crohn's disease (CD) or ulcerative colitis (UC) includes a family history of CRC, personal history of dysplasia, history of strictures, or primary sclerosing cholangitis (PSC). Dysplasia is the precursor of cancer and ensuring effective surveillance strategies is vital for early detection and intervention. In the past, dysplasia detection relied on random biopsies, but recent studies have shown that, with the adaptation of high-definition white light endoscopy (HD-WLE), dye sprayed chromoendoscopy (DCE) and virtual chromoendoscopy (VCE), dysplasia detection has improved. While there exists a certain degree of consensus amongst experts regarding the management of dysplasia, it is important to implement a personalized approach to each patient's care. Our review focuses on advancements in the past two decades, specifically highlighting the modifications that have been implemented since the SCENIC guidelines. It also explores future directions, including the potential implementation of stool studies as a non-invasive tool for surveillance and the emerging role of artificial intelligence (AI) in dysplasia detection.

High-definition chromoendoscopy results in more significant dysplasia detection than white light endoscopy with random biopsies in ulcerative colitis patients: A single-center retrospective study.

The goal of this study was to determine whether high-definition white light endoscopy with random biopsies (HD-WLR) or chromoendoscopy (HDCE) yielded a higher dysplasia detection rate in ulcerative colitis patients. Ulcerative colitis (UC) patients have a 2.4-fold increased future risk of developing colorectal cancer compared to the general population and require careful dysplasia screening modalities. Both HD-WLR and HDCE are regularly used, and recent guidelines do not suggest a preference. UC patients who underwent dysplasia surveillance at our site between January 2019 and 2021 were retrospectively reviewed. We calculated the dysplasia detection rate of both techniques at the first CRC screening colonoscopy. Eighteen dysplastic lesions were detected in total, 3 by HD-WLR and fifteen by HDCE. Dysplasia was detected in 4% (3/75) and 20% (15/75) of UC patients by HD-WLR and HDCE respectively, with significantly fewer biopsies (4.44 ± 4.3 vs 29.1 ± 13.0) required using the former. HD-WLR detected 2 polypoid and one non-polypoid lesion, while HDCE detected eleven polypoid and 4 non-polypoid lesions. No invisible dysplasia or colorectal cancer was detected. Screening was performed at 10.8 ± 4.8 and 9.72 ± 3.05 years following UC diagnosis for HDCE and HD-WLR respectively. Median withdrawal time was 9.0 ± 2.7 minutes (HD-WLR) vs 9.6 + 3.9 minutes (HDCE). HDCE is associated with higher dysplasia detection rates compared to HD-WLR in a UC patient population. Given the former technique is less tedious and costly, our findings complement existing studies that suggest HDCE may be considered over HD-WLR for UC dysplasia surveillance.

OP15 High-definition white light endoscopy with segmental re-inspection is non-inferior compared to dye-based chromoendoscopy in Inflammatory Bowel Disease: the randomized controlled HELIOS trial

Abstract Background Patients with colonic inflammatory bowel disease (IBD) undergo endoscopic surveillance to detect and remove colorectal neoplasia (CRN). Although high-definition dye-based chromo-endoscopy (HD-CE) is the recommended modality in guidelines, high-definition white light endoscopy (HD-WLE) with matched procedural time may yield similar neoplasia detection rates. We designed a non-blinded, randomized controlled trial in four academic hospitals aiming to compare three endoscopic surveillance techniques in IBD patients for the outcome of CRN detection rate. Methods Eligible patients were aged ≥18 years and scheduled for colitis-associated CRN surveillance according to Dutch IBD surveillance guidelines. Patients were excluded in case of insufficient bowel cleansing, active colitis, or if >50% of the colon was resected. Patients were randomly assigned (2:2:1) to undergo HD-WLE with segmental re-inspection (SR), HD-CE, or single pass HD-WLE. The primary outcome was CRN detection rate, defined as the proportion of procedures in which macroscopic CRN was detected. Secondary outcomes included the number of CRN and withdrawal time. To demonstrate non-inferiority of HD-WLE with SR compared to HD-CE (one-sided testing, α=0.05, 1−β=0.8, non-inferiority (NI) margin -10%), and superiority compared to single-pass HD-WLE (two-sided testing, estimated CRN detection rate of 24% and 12%, respectively1) with Mantel-Haenszel analyses, a total of 566 patients were needed. Results In total, 666 patients were randomized, 563 fulfilled all study criteria and were analysed per protocol (table 1). Of these, 51.8% were male, with a median age of 51 years (interquartile range 35-63). CRN detection rates were 9.8% for HD-WLE with SR, 13.1% for HD-CE, and 6.1% for single pass HD-WLE. HD-WLE with SR was non-inferior compared to HD-CE (Δ-3.1%, lower boundary of the 95% confidence interval (CI) -8.1 not exceeding the NI margin of -10%, p<.05). HD-WLE with SR was not superior compared to single-pass HD-WLE (Δ3.7%, 95% CI -2.5:9.1%, p=0.31). A significant difference was found between arms for the number of detected CRN (n=29 vs n=36 vs n=8 for HD-WLE with SR, HD-CE and single-pass HD-WLE, respectively (p=.04)) and withdrawal time (p=.03, table 1). One advanced lesion was detected (high-grade dysplasia in the HD-CE arm). Conclusion In this large, randomized controlled trial, HD-WLE with SR was non-inferior compared to HD-CE for CRN detection in IBD patients. HD-WLE with SR was not superior to single-pass HD-WLE, although this may have resulted from lower than expected neoplasia yields and subsequent lower power. These results suggest that HD-WLE with SR may provide a feasible alternative to HD-CE in clinical practice (NCT04291976). 1Imperatore et al. JCC 2019;13(6):714-24

Advanced endoscopic imaging for detection of Barrett's esophagus.

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC), and is caused by chronic gastroesophageal reflux. BE can progress over time from metaplasia to dysplasia, and eventually to EAC. EAC is associated with a poor prognosis, often due to advanced disease at the time of diagnosis. However, if BE is diagnosed early, pharmacologic and endoscopic treatments can prevent progression to EAC. The current standard of care for BE surveillance utilizes the Seattle protocol. Unfortunately, a sizable proportion of early EAC and BE-related high-grade dysplasia (HGD) are missed due to poor adherence to the Seattle protocol and sampling errors. New modalities using artificial intelligence (AI) have been proposed to improve the detection of early EAC and BE-related HGD. This review will focus on AI technology and its application to various endoscopic modalities such as high-definition white light endoscopy, narrow-band imaging, and volumetric laser endomicroscopy.

Dye Chromoendoscopy Outperforms High-Definition White Light Endoscopy in Dysplasia Detection for Patients With Inflammatory Bowel Disease: An Updated Meta-Analysis of Randomized Controlled Trials.

Whether dye spray chromoendoscopy (DCE) adds value in surveillance colonoscopy with high-definition (HD) scopes remains controversial. This updated meta-analysis compares dysplasia detection using DCE and high-definition white light endoscopy (HD-WLE) in patients with inflammatory bowel disease (IBD) undergoing surveillance colonoscopy. A comprehensive search was performed for randomized controlled trials (RCT) comparing HD-WLE and DCE in patients with IBD. The primary outcome was to compare the proportion of patients with at least 1 dysplastic lesion detected by DCE vs HD-WLE. Odds ratios (OR) and 95% confidence intervals (CI) were pooled using the random-effects model, with I2 > 60% indicating substantial heterogeneity. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the certainty of evidence (CoE). Six RCT involving 978 patients were analyzed (DCE = 479 vs HD-WLE = 499 patients). DCE detected significantly more patients with dysplasia than HD-WLE (18.8% vs 9.4%), OR 1.94 (95% CI 1.21-3.11, I2 = 28%, P = 0.006, high CoE). This remained significant after excluding 2 RCT published as abstracts. A sensitivity analysis excluding a noninferiority RCT with a single experienced operator eliminated the results' heterogeneity, OR 2.46 (95% CI 1.56-3.90, I2 = 0%). Although high-grade dysplasia detection was numerically higher in the DCE group (2.8% vs 1.1%), the difference was statistically insignificant, OR 2.21 (95% CI 0.64-7.62, I2 = 0%, low CoE). Our updated meta-analysis supports DCE as a superior strategy in overall dysplasia detection in IBD, even with HD scopes. When expertise is available, DCE should be considered for surveillance colonoscopy in patients with high-risk IBD, with the acknowledgment that virtual chromoendoscopy shows equivalence in recent studies. Further multicenter trials with multiple endoscopists with varying expertise levels and longer-term outcome data showing a reduction in cancer or cancer-related death are needed.

Diagnosis and management of Barrett esophagus: European Society of Gastrointestinal Endoscopy (ESGE) Guideline.

MR1 : ESGE recommends the following standards for Barrett esophagus (BE) surveillance:- a minimum of 1-minute inspection time per cm of BE length during a surveillance endoscopy- photodocumentation of landmarks, the BE segment including one picture per cm of BE length, and the esophagogastric junction in retroflexed position, and any visible lesions- use of the Prague and (for visible lesions) Paris classification- collection of biopsies from all visible abnormalities (if present), followed by random four-quadrant biopsies for every 2-cm BE length.Strong recommendation, weak quality of evidence. MR2: ESGE suggests varying surveillance intervals for different BE lengths. For BE with a maximum extent of ≥ 1 cm and < 3 cm, BE surveillance should be repeated every 5 years. For BE with a maximum extent of ≥ 3 cm and < 10 cm, the interval for endoscopic surveillance should be 3 years. Patients with BE with a maximum extent of ≥ 10 cm should be referred to a BE expert center for surveillance endoscopies. For patients with an irregular Z-line/columnar-lined esophagus of < 1 cm, no routine biopsies or endoscopic surveillance are advised.Weak recommendation, low quality of evidence. MR3: ESGE suggests that, if a patient has reached 75 years of age at the time of the last surveillance endoscopy and/or the patient's life expectancy is less than 5 years, the discontinuation of further surveillance endoscopies can be considered. Weak recommendation, very low quality of evidence. MR4: ESGE recommends offering endoscopic eradication therapy using ablation to patients with BE and low grade dysplasia (LGD) on at least two separate endoscopies, both confirmed by a second experienced pathologist.Strong recommendation, high level of evidence. MR5: ESGE recommends endoscopic ablation treatment for BE with confirmed high grade dysplasia (HGD) without visible lesions, to prevent progression to invasive cancer.Strong recommendation, high level of evidence. MR6: ESGE recommends offering complete eradication of all remaining Barrett epithelium by ablation after endoscopic resection of visible abnormalities containing any degree of dysplasia or esophageal adenocarcinoma (EAC).Strong recommendation, moderate quality of evidence. MR7: ESGE recommends endoscopic resection as curative treatment for T1a Barrett's cancer with well/moderate differentiation and no signs of lymphovascular invasion.Strong recommendation, high level of evidence. MR8: ESGE suggests that low risk submucosal (T1b) EAC (i. e. submucosal invasion depth ≤ 500 µm AND no [lympho]vascular invasion AND no poor tumor differentiation) can be treated by endoscopic resection, provided that adequate follow-up with gastroscopy, endoscopic ultrasound (EUS), and computed tomography (CT)/positrion emission tomography-computed tomography (PET-CT) is performed in expert centers.Weak recommendation, low quality of evidence. MR9: ESGE suggests that submucosal (T1b) esophageal adenocarcinoma with deep submucosal invasion (tumor invasion > 500 µm into the submucosa), and/or (lympho)vascular invasion, and/or a poor tumor differentiation should be considered high risk. Complete staging and consideration of additional treatments (chemotherapy and/or radiotherapy and/or surgery) or strict endoscopic follow-up should be undertaken on an individual basis in a multidisciplinary discussion.Strong recommendation, low quality of evidence. MR10 A: ESGE recommends that the first endoscopic follow-up after successful endoscopic eradication therapy (EET) of BE is performed in an expert center.Strong recommendation, very low quality of evidence. B: ESGE recommends careful inspection of the neo-squamocolumnar junction and neo-squamous epithelium with high definition white-light endoscopy and virtual chromoendoscopy during post-EET surveillance, to detect recurrent dysplasia.Strong recommendation, very low level of evidence. C: ESGE recommends against routine four-quadrant biopsies of neo-squamous epithelium after successful EET of BE.Strong recommendation, low level of evidence. D: ESGE suggests, after successful EET, obtaining four-quadrant random biopsies just distal to a normal-appearing neo-squamocolumnar junction to detect dysplasia in the absence of visible lesions.Weak recommendation, low level of evidence. E: ESGE recommends targeted biopsies are obtained where there is a suspicion of recurrent BE in the tubular esophagus, or where there are visible lesions suspicious for dysplasia.Strong recommendation, very low level of evidence. MR11: After successful EET, ESGE recommends the following surveillance intervals:- For patients with a baseline diagnosis of HGD or EAC:at 1, 2, 3, 4, 5, 7, and 10 years after last treatment, after which surveillance may be stopped.- For patients with a baseline diagnosis of LGD:at 1, 3, and 5 years after last treatment, after which surveillance may be stopped.Strong recommendation, low quality of evidence.

Current status of image-enhanced endoscopy in inflammatory bowel disease.

In inflammatory bowel disease (IBD), chronic inflammation leads to unfavorable clinical outcomes and increases the risk of developing colorectal neoplasm (CRN); thereby highlighting the importance of endoscopically evaluating disease activity as well as detecting and characterizing CRN in patients with IBD. With recent advances in image-enhanced endoscopic (IEE) technologies, especially virtual chromoendoscopy (VCE) platforms, this review discusses state-of-the-art IEE techniques and their applicability in assessing disease activity and surveillance colonoscopy in patients with IBD. Among various IEE, VCE demonstrated the capacity to identify quiescent disease activity. And endoscopic remission defined by the new scoring system using VCE platform better predicted clinical outcomes, which may benefit the tailoring of therapeutic strategies in patients with IBD. High-definition dye-chromoendoscopy (HD-DCE) is numerically superior to high-definition white light endoscopy (HD-WLE) in detecting CRN in IBD; however, discrepancy is observed in the statistical significance. VCE showed comparable performance in detecting dysplasia to HD-WLE or DCE and potential for optical diagnosis to differentiate neoplastic from nonneoplastic lesions during surveillance colonoscopy. Applying these novel advanced IEE technologies would provide opportunities for personalized medicine in IBD and optimal treatment of CRN in patients with IBD.

The incremental yield of adenoma detection with I-Scan versus high-definition white light colonoscopy-a systematic review and meta-analysis of randomized studies.

The incremental yield of I-Scan virtual chromoendoscopy compared to high-definition white light endoscopy (HD-WLE) in detection of colorectal adenomas has not been thoroughly elucidated. A systematic search from inception to April 2023 was conducted to identify randomized controlled trials (RCTs) comparing I-Scan to HD-WLE for detection of adenomas. A random effects model was used to compute risk difference (RD) with corresponding 95% confidence intervals in adenoma detection rate (ADR). Influence analysis was done to assess robustness of findings. The number needed to diagnose was computed. Heterogeneity was assessed using the I2 statistic and explored further by subgroup analyses defined a priori. Certainty in effect estimates was assessed using the GRADE approach. We identified four studies (I-Scan n = 730, HD-WLE n = 765). I-Scan increased adenoma detection by 9% (risk difference (RD), 0.09; 0.04, 0.14; I2 02%; certainty, low). Influence analysis revealed that the gain in yield remained statistically significant with exclusion of all but one study. The number needed to capture one additional adenomatous polyp with I-Scan use was 11.2. I-Scan 1 use was associated with a statistically significant gain in ADR, whereas no significant difference in ADR was noted with I-Scan use on subgroup analysis. In conclusion, I-Scan increases the yield of adenoma detection by 9% compared to HD-WLE, with low certainty in the estimate of this effect. Data on the gain in yield of detecting large polyps, sessile serrated lesions, and on the impact of formally training endoscopists and trainees in I-Scan use and similar technology on adenoma detection rate are needed.

Identifying the real-world challenges of dysplasia surveillance in inflammatory bowel disease: a retrospective cohort study in a tertiary health network.

Dysplasia surveillance in inflammatory bowel disease (IBD) is often suboptimal and deviates from guidelines. To assess dysplasia surveillance behaviours and adherence to guidelines amongst a large tertiary teaching health network with a specialised IBD unit to identify areas where dysplasia surveillance could be improved. A retrospective audit of IBD surveillance colonoscopy practice over an 18-month period was performed using the Provation Endoscopy Database and the hospital's primary sclerosing cholangitis database. The audit identified 115 dysplasia surveillance colonoscopies. A total of 37% of index dysplasia colonoscopies were outside recommended guidelines. A total of 10% had inadequate bowel preparation and only 40% had excellent bowel preparation. A total of 28% of patients underwent dye-based chromoendoscopy and 69% underwent high-definition white-light endoscopy. Dye chromoendoscopy was more likely to be used by IBD specialists than interventional endoscopists (P = 0.008) and other endoscopists (P = 0.004). Only IBD specialists and interventional endoscopists used dye chromoendoscopy. Dysplasia or colorectal cancer was detected in 3.4% of the colonoscopies. Overall, the several dysplasia examinations were lower than expected. Dysplasia surveillance in the IBD population remains an area of improvement given the current national guidelines. IBD specialists are more likely to perform dye chromoendoscopy than other endoscopists/gastroenterologists. Dysplasia rates in this real-world contemporary setting are less than expected in historical studies and may represent improvements in IBD management principles and medications.

Current progress on the endoscopic features of colorectal sessile serrated lesions.

Along with the discovery and refinement of serrated pathways, the World Health Organization amended the classification of digestive system tumors in 2019, recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions (SSLs). Given the particularity of the endoscopic appearance of SSLs, it could easily be overlooked and missed in colonoscopy screening, which is crucial for the occurrence of interval colorectal cancer. Existing literature has found that adequate bowel preparation, reasonable withdrawal time, and awareness of colorectal SSLs have improved the quality and accuracy of detection. More particularly, with the continuous advancement and development of endoscopy technology, equipment, and accessories, a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs. High-definition white light endoscopy, chromoendoscopy, and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size, shape, character, risk degree, and potential malignant tendency. This article delves into the relevant factors influencing the detection rate of colorectal SSLs, reviews its characteristics under various endoscopic techniques, and expects to attract the attention of colonoscopists.

A200 HIGH-DEFINITION CHROMOENDOSCOPY RESULTS IN MORE SIGNIFICANT DYSPLASIA DETECTION THAN WHITE LIGHT ENDOSCOPY WITH RANDOM BIOPSIES IN ULCERATIVE COLITIS PATIENTS

Abstract Background Ulcerative colitis (UC) is an inflammatory bowel disease that results in inflammation of the colonic mucosa, leading to abdominal pain, rectal bleeding, weight loss, and diarrhea. This chronic inflammation results in a 2.4-fold increased future risk of developing colorectal cancer (CRC) in UC patients compared to the general population. Thus, careful dysplasia screening modalities are required to prevent progression to CRC. Currently, both high-definition white light endoscopy with non-targeted biopsies (HD-WLR) and dye-spray chromoendoscopy (HDCE) are regularly used across Canada for dysplasia surveillance given existing research has been inconclusive regarding superiority of one particular method, and that recent guidelines do not suggest a preference. Purpose The primary objective of this study was to determine which surveillance modality yielded a higher dysplasia detection rate in UC patients, both by calculating the total number of dysplastic lesions detected, as well as calculating the number of patients with at least one dysplastic lesion detected using either technique. Method We conducted a single-centre retrospective chart review of 150 UC patients who underwent dysplasia surveillance at our site between January 2019-2021. We calculated the dysplasia detection rate of both techniques at the time of the first CRC screening colonoscopy. Result(s) Eighteen dysplastic lesions were detected in total, three by HD-WLR and fifteen by HDCE. Dysplasia was detected in 4% (3/75) and 14.5% (15/75) of UC patients by HD-WLR and HDCE respectively, with significantly fewer biopsies (4.44 + 4.3 vs 29.1 + 13.0) required. HD-WLR detected two polypoid and one non-polypoid lesion, while HDCE detected eleven polypoid and four non-polypoid lesions. No invisible dysplasia or colorectal cancer was detected. Screening was performed at 10.8 + 4.8 and 9.72 + 3.05 years following UC diagnosis for HDCE and HD-WLR respectively. Median withdrawal time was 9.0 + 2.7 min (HD-WLR) vs 9.6 + 3.9min (HDCE). Image Conclusion(s) HDCE resulted in higher dysplasia detection rates compared to HD-WLR in a UC patient population. Given the former technique is less tedious and costly, our findings suggest HDCE should be considered over HD-WLR for UC dysplasia surveillance. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared

Development of a Low-Cost Gastroscope Prototype (GP) for Potential Cost-Effective Gastric Cancer Screening in Prevalent Regions

Abstract Background Screening for gastric cancer is known to be associated with reduced mortality in populations with high prevalence. However, many countries with high prevalence do not screen, with high costs being a significant reason for this. Aims To describe, develop, and assess the potential for a low-cost gastroscope for early cancer screening and patient risk stratification. Methods Our interdisciplinary team used both off-the-shelf and fabricated components to create multiple gastroscope prototypes (GP) in iterative fashion based off clinician feedback. Clinician endoscopists were surveyed using Likert scales regarding device potential, video quality, and handling when testing on a GI training device. Video quality comparison to clinically standard high-definition white light endoscopy (HD-WLE) was done using the absolute categorical ratings (ACR) method. Results A candidate cost-effective GP with clinical potential was developed. Although initial versions were scored as inferior via ACR on all views tested when compared to HD-WLE (p &lt; 0.001), participants agreed the concept may be beneficial (M = 4.52/5, SD = 0.72). In testing improved versions, participants agreed the device had the ability to identify discrete (M = 4.62/5, SD = 0.51) and subtle lesions (M = 4/5, SD = 0.7) but most felt video quality, although improved, was still less than HD-WLE. Sufficiency of maneuverability of device to visualize gastric views was rated as equivocal (M = 2.69/5, SD = 1.25). Conclusion The presented low-cost gastroscopic devices have potential for clinical application. With further device development and refinement including the possible addition of technologies in telemedicine and artificial intelligence, we hope the GP can help expand gastric cancer screening for populations in need.

P812 Fluorescently labelled vedolizumab identified macroscopic and microscopic mucosal drug distribution in patients with inflammatory bowel disease

Abstract Background Biological treatment in inflammatory bowel disease (IBD) patients is currently hampered by high non-response rates. To enhance personalized medicine and predict response to biological therapeutics such as vedolizumab, the working mechanism should be elucidated. We aimed to visualize macroscopic and microscopic vedolizumab distribution and detect drug target cells during quantified fluorescence molecular endoscopy (QFME) to improve understanding of the mechanism of action. Methods Vedolizumab-800CW was developed and GMP produced. Forty-three QFME procedures were performed in thirty-seven IBD patients two to four days after intravenous administration of vedolizumab-800CW. Each QFME procedure consisted out of endoscopic assessment of the inflammation status per colonic segment by high-definition white light endoscopy, followed by real-time in vivo assessment of the macro-distribution of fluorescent vedolizumab-800CW signal and quantification by spectroscopy of selected segments. Dose escalation was performed using 0.0 mg, 4.5 mg and 15 mg. Subsequently, two patient cohorts were added that received a dose of 75 mg or 300 mg unlabelled vedolizumab prior to vedolizumab-800CW to assess target saturation. Tissue biopsies were obtained for histopathological assessment, for further ex vivo analysis of the fluorescent signal and for visualization of the microscopic distribution and identification of vedolizumab-800CW target cells by fluorescence microscopy (fig 1). Results Both during in vivo QFME and ex vivo analysis a clear dose- and inflammation severity-dependent increase of the fluorescent drug signal was revealed (fig 2). A significant difference was found between the dose groups for non-inflamed (p=0.0004), mild inflamed (p=0.0397) and severe inflamed (p=0.0056) tissue. In addition, the difference in intrinsic fluorescence between the severe inflamed tissue and non-inflamed tissue was significant within the 15 mg (p&amp;lt;0.0001), 75 mg + 15 mg (p=0.0118) and the therapy + 15 mg group (p=0.0005). Fluorescence microscopy revealed clear membrane binding of vedolizumab-800CW to inflammatory cells and migration into the inflamed mucosa. Additional analyses to identify specific target cells are ongoing and immune compositions of regions with high and low vedolizumab signal will be unravelled. Conclusion QFME using vedolizumab-800CW elucidated novel detailed macroscopic and microscopic vedolizumab distribution in the inflamed target organ. In addition, its shows the potential of QFME to better understand local drug distribution, target cell identification and target engagement, which could improve understanding of targeted drugs over standard pharmacokinetic and pharmacodynamic analysis.

Detection of Early Esophageal Neoplastic Barrett Lesions with Quantified Fluorescence Molecular Endoscopy Using Cetuximab-800CW.

Esophageal adenocarcinoma causes 6% of cancer-related deaths worldwide. Near-infrared fluorescence molecular endoscopy (NIR-FME) uses a tracer that targets overexpressed proteins. In this study, we aimed to investigate the feasibility of an epidermal growth factor receptor (EGFR)-targeted tracer, cetuximab-800CW, to improve detection of early-stage esophageal adenocarcinoma. Methods: We validated EGFR expression in 73 esophageal tissue sections. Subsequently, we topically administered cetuximab-800CW and performed high-definition white-light endoscopy (HD-WLE), narrow-band imaging, and NIR-FME in 15 patients with Barrett esophagus (BE). Intrinsic fluorescence values were quantified using multidiameter single-fiber reflectance and single-fiber fluorescence spectroscopy. Back-table imaging, histopathologic examination, and EGFR immunohistochemistry on biopsy samples collected during NIR-FME procedures were performed and compared with invivo imaging results. Results: Immunohistochemical preanalysis showed high EGFR expression in 67% of dysplastic tissue sections. NIR-FME visualized all 12 HD-WLE-visible lesions and 5 HD-WLE-invisible dysplastic lesions, with increased fluorescence signal in visible dysplastic BE lesions compared with nondysplastic BE as shown by multidiameter single-fiber reflectance/single-fiber fluorescence, reflecting a target-to-background ratio of 1.5. Invisible dysplastic lesions also showed increased fluorescence, with a target-to-background ratio of 1.67. Immunohistochemistry analysis showed EGFR overexpression in 16 of 17 (94%) dysplastic BE lesions, which all showed fluorescence signal. Conclusion: This study has shown that NIR-FME using cetuximab-800CW can improve detection of dysplastic lesions missed by HD-WLE and narrow-band imaging.

The yield of dysplasia and serrated lesions in a single-centre tertiary inflammatory bowel disease cohort.

Chromoendoscopy is preferred over high-definition white light endoscopy (HDWLE) for dysplasia surveillance in inflammatory bowel disease (IBD) patients, but is more time-consuming to perform and real-world evidence is limited. The prevalence of sessile serrated lesions (SSLs) in IBD patients is also unknown. To determine the yield of polypoid and non-polypoid dysplasia and SSLs in IBD patients undergoing dysplasia surveillance and the associations for these lesions. A retrospective cohort study from a tertiary IBD centre. A keyword search of the colonoscopy reporting system was performed. IBD patients with colonic disease that underwent colonoscopy for surveillance between 1 February 2015 and 1 February 2018 were included. Clinical, endoscopic and histopathological outcomes were extracted for the analysis. Of 2114 patients identified, 276 eligible colonoscopies in 126 patients were analysed. The median age at colonoscopy was 51 years (interquartile range: 42-58 years). 71/126 (56%) of colonoscopies were performed in male patients, with 57/126 (45%) having ulcerative colitis, 68/126 (54%) Crohn's colitis and 1/126 (0.79%) IBD-unspecified. The prevalence for any neoplasia was 75/276 (27%). The prevalence for all serrated lesions was 43/276 (16%). Increased age was a risk factor for finding a neoplastic lesion on both univariate and multivariate analyses. Chromoendoscopy was associated with twice the odds of finding a neoplastic lesion (odds ratio: 1.99, 95% confidence interval: 1.13-3.51, p = 0.02), on multivariate analysis. No factor was associated with an increased risk of finding a serrated lesion. Significant neoplastic lesions and serrated lesions were detected in 27% and 16% of colonoscopies performed in IBD patients, respectively, with the highest yield in older patients. Chromoendoscopy significantly increased neoplasia yield compared to HDWLE and still has a robust utility in this pragmatic real-world study.

Adherence to Quality Indicators for Diagnosis and Surveillance of Barrett's Esophagus: A Comparative Study of Barrett's Experts and Nonexperts

Background and AimsThere is considerable variability in adherence to endoscopic quality indicators (QIs) for Barrett's esophagus (BE). The aims of this study were to (1) assess adherence to published Qis for diagnosis and surveillance of BE, (2) compare adherence between BE experts and nonexperts, and (3) identify factors associated with adherence. MethodsWe identified all patients with BE on esophagogastroduodenoscopy between 2010 and 2018. QIs evaluated included inspection using high-definition white light endoscopy, use of the Prague Classification, identification of endoscopic landmarks, use of the Seattle Protocol, and guideline-adherent recommendations for surveillance or endoscopic eradication therapy. BE experts and nonexperts were compared using logistic mixed-effects models. ResultsA total of 467 patients were identified, with BE experts performing fewer overall esophagogastroduodenoscopies (n = 162, 34.7% vs n = 305, 65.3%). Whereas BE experts were more likely to document Prague Classification (52.5% vs 41.3%; P = 0.017) and landmarks (43.2% vs 22.6%; P = 0.036), there was no significant difference between experts and nonexperts in use of high-definition white light endoscopy (8.6% vs 3.3%; P = 0.123), Seattle Protocol (48.1% vs 40.3%; P = 0.313), or guideline-adherent surveillance or treatment recommendations (71.0% vs 67.5%; P = 0.509). Patient enrollment in a BE surveillance program was the only factor associated with improved QI adherence, specifically adherence to Prague Classification documentation (OR 1.85, 95% CI 1.08-3.14; P = 0.025), Seattle Protocol (1.28, 95% CI 1.16-1.50; P < 0.001), and follow-up recommendations (OR 2.64, 95% CI 1.55-4.48; P < 0.001). ConclusionPatterns of adherence to published QIs for endoscopy in patients with BE are mostly independent of expertise. Further training initiatives are needed to standardize the performance of endoscopic practice in patients with BE.

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors.

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

S2294 Endoscopic Management of Esophageal Cancer in a Patient with Decompensated Cirrhosis: The Importance of Multidisciplinary Collaboration and Peri-Procedure Planning in Complex Clinical Scenarios

Introduction: Endoscopic therapy is effective for management of early esophageal cancer (EC), however serious complications such as bleeding and perforation can occur. Patient selection, optimization of co-morbidities and peri-procedure management help mitigate risk and improve patient outcomes. We present a patient with decompensated cirrhosis who required complex peri-procedure planning prior to endoscopic treatment of early EC. Case Description/Methods: A 71-year male with decompensated cirrhosis (portal hypertension, esophageal varices, ascites) and recent DVT on apixaban was found to have a 1cm raised focal lesion at the GEJ; biopsies revealed high-grade dysplasia (HGD). He was referred for endoscopic mucosal resection (EMR). After extensive discussion with hematology, patient was admitted for anticoagulation management with intravenous (IV) heparin. EGD confirmed an 8mm nodule at the GEJ (Figure 1A,B,C). Grade 3 non-bleeding esophageal varices were noted at the GEJ and in the distal esophagus, prohibiting safe EMR. Biopsies again showed HGD. After multidisciplinary tumor board discussion, a transjugular portosystemic shunt (TIPS) was performed to decompress the portal system and reduce bleeding risk from the planned EMR. Doppler ultrasound a few weeks later confirmed patent TIPS. Repeat diagnostic EGD showed decompression of varices. EUS revealed a mucosal lesion with no lymphadenopathy. Biopsy revealed intramucosal adenocarcinoma. Based on this evaluation and after detailed discussion with the patient, EMR was planned with appropriate anticoagulation management. En-bloc multiband mucosectomy was performed (Figure 1D,E). Intraprocedural bleeding was controlled with band ligation and hemostatic spray (Figure 1F). Patient remained inpatient for observation on octreotide and IV pantoprazole drip without further bleeding. Apixaban 2.5mg was resumed on day 3 and he was discharged home on acid suppression. Pathology confirmed well-differentiated adenocarcinoma, pT1a. Tumor board discussion recommended continued endotherapy (cryotherapy) to the residual dysplastic Barrett’s mucosa which he is tolerating well. Discussion: Endoscopic treatment is effective for the management of early EC. However, when complex scenarios present in an elderly frail patient, multidisciplinary collaborative management and stepwise risk-mitigation strategies need to be in place to minimize morbidity and maximize success (Table). Tumor board and shared decision making are key patient centric strategies that reflect best practice.Figure 1.: A: Nodular distal esophageal lesion; B: Lesion in high-definition white light endoscopy (HDWLE); C: Lesion in narrow band imaging (NBI), D: Band placed at the base of the lesion, E: EMR defect, F: Hemostatic spray was used to achieve hemostasis of an area of focal bleeding after EMR. Table 1. - Risk Mitigation Strategies in Complex Endoscopy Practice – Best Practice Principles Pre-procedure consultation (nonemergent diagnostic/elective procedures) Pre-procedure planning (labs, imaging) Optimization of treatment for co-morbidities Anesthesia consultation Detailed high-risk informed consent Shared decision making Multidisciplinary GI tumor board discussion Medical record documentation Guideline-based anti-thrombotic management Appropriate procedure back-up and support (IR, surgery, radiology, critical care)

In vivo computer-aided diagnosis of colorectal polyps using white light endoscopy.

Background and study aims Artificial intelligence is currently able to accurately predict the histology of colorectal polyps. However, systems developed to date use complex optical technologies and have not been tested in vivo. The objective of this study was to evaluate the efficacy of a new deep learning-based optical diagnosis system, ATENEA, in a real clinical setting using only high-definition white light endoscopy (WLE) and to compare its performance with endoscopists. Methods ATENEA was prospectively tested in real life on consecutive polyps detected in colorectal cancer screening colonoscopies at Hospital Clínic. No images were discarded, and only WLE was used. The in vivo ATENEA’s prediction (adenoma vs non-adenoma) was compared with the prediction of four staff endoscopists without specific training in optical diagnosis for the study purposes. Endoscopists were blind to the ATENEA output. Histology was the gold standard. Results Ninety polyps (median size: 5 mm, range: 2–25) from 31 patients were included of which 69 (76.7 %) were adenomas. ATENEA correctly predicted the histology in 63 of 69 (91.3 %, 95 % CI: 82 %–97 %) adenomas and 12 of 21 (57.1 %, 95 % CI: 34 %–78 %) non-adenomas while endoscopists made correct predictions in 52 of 69 (75.4 %, 95 % CI: 60 %–85 %) and 20 of 21 (95.2 %, 95 % CI: 76 %–100 %), respectively. The global accuracy was 83.3 % (95 % CI: 74%–90 %) and 80 % (95 % CI: 70 %–88 %) for ATENEA and endoscopists, respectively. Conclusion ATENEA can accurately be used for in vivo characterization of colorectal polyps, enabling the endoscopist to make direct decisions. ATENEA showed a global accuracy similar to that of endoscopists despite an unsatisfactory performance for non-adenomatous lesions.

Identification of visible lesions during surveillance endoscopy for Barrett’s esophagus: a video-based survey study

Visible lesion (VL) detection is essential in patients with Barrett's esophagus (BE). We sought to assess the rate of VL detection by academic and community endoscopists using high-definition white-light endoscopy (HD-WLE) and narrow-band imaging (NBI) during surveillance endoscopy. Fifty endoscopists were invited to participate in a prospective video survey study. Participants viewed 25 standardized clips of patients referred for endoscopic therapy. Participants noted identification of anatomic landmarks and VLs using HD-WLE and NBI and reported practice-level data. The criterion standard of VL identification was established by consensus of 5 BE experts. Our primary outcome was the rate of VL identification using HD-WLE and NBI. Forty-four of 50 participants completed the study (22 academic and 22 community). Compared with the criterion standard, participants did not identify 28% (HD-WLE) and 31% (NBI) of VLs. Community endoscopists had more experience (>5 years in practice: community 85% vs academic 54.5%, P= .041; >5 surveillance endoscopies a month: community 85% vs academic 31.8%, P= .046). Across all participants, VL detection using NBI improved significantly with a minimum of 5 surveillance endoscopies per month (area under the curve= .72; 95% confidence interval, .56-.85; P= .006). Despite improved endoscope resolution and availability of virtual chromoendoscopy, the overall rate of VL detection remains low. Identification of VLs using NBI may be volume dependent. Further education and training efforts focused on VL detection during BE surveillance endoscopy are needed.