Linda K Wanders

Diagnostic performance of narrowed spectrum endoscopy, autofluorescence imaging, and confocal laser endomicroscopy for optical diagnosis of colonic polyps: a meta-analysis

BACKGROUND Novel endoscopic technologies could allow optical diagnosis and resection of colonic polyps without histopathological testing. Our aim was to establish the sensitivity, specificity, and real-time negative predictive value of three types of narrowed spectrum endoscopy (narrow-band imaging [NBI], image-enhanced endoscopy [i-scan], and Fujinon intelligent chromoendoscopy [FICE]), confocal laser endomicroscopy (CLE), and autofluorescence imaging for differentiation between neoplastic and non-neoplastic colonic lesions. METHODS We identified relevant studies through a search of Medline, Embase, PubMed, and the Cochrane Library. Clinical trials and observational studies were eligible for inclusion when the diagnostic performance of NBI, i-scan, FICE, autofluorescence imaging, or CLE had been assessed for differentiation, with histopathology as the reference standard, and for which a 2 × 2 contingency table of lesion diagnosis could be constructed. We did a random-effects bivariate meta-analysis using a non-linear mixed model approach to calculate summary estimates of sensitivity and specificity, and plotted estimates in a summary receiver-operating characteristic curve. FINDINGS We included 91 studies in our analysis: 56 were of NBI, ten of i-scan, 14 of FICE, 11 of CLE, and 11 of autofluorescence imaging (more than one of the investigated modalities assessed in eight studies). For NBI, overall sensitivity was 91·0% (95% CI 88·6-93·0), specificity 85·6% (81·3-89·0), and real-time negative predictive value 82·5% (75·4-87·9). For i-scan, overall sensitivity was 89·3% (83·3-93·3), specificity 88·2% (80·3-93·2), and real-time negative predictive value 86·5% (78·0-92·1). For FICE, overall sensitivity was 91·8% (87·1-94·9), specificity 83·5% (77·2-88·3), and real-time negative predictive value 83·7% (77·5-88·4). For autofluorescence imaging, overall sensitivity was 86·7% (79·5-91·6), specificity 65·9% (50·9-78·2), and real-time negative predictive value 81·5% (54·0-94·3). For CLE, overall sensitivity was 93·3% (88·4-96·2), specificity 89·9% (81·8-94·6), and real-time negative predictive value 94·8% (86·6-98·1). INTERPRETATION All endoscopic imaging techniques other than autofluorescence imaging could be used by appropriately trained endoscopists to make a reliable optical diagnosis for colonic lesions in daily practice. Further research should be focused on whether training could help to improve negative predictive values. FUNDING None.

Cancer risk after resection of polypoid dysplasia in patients with longstanding ulcerative colitis: a meta-analysis

BACKGROUND & AIMS American and European guidelines propose complete endoscopic resection of polypoid dysplasia (adenomas or adenoma-like masses) in patients with longstanding colitis, with close endoscopic follow-up. The incidence of cancer after detection of flat low-grade dysplasia or dysplasia-associated lesion or mass is estimated at 14 cases/1000 years of patient follow-up. However, the risk for polypoid dysplasia has not been determined with precision. We investigated the risk of cancer after endoscopic resection of polypoid dysplasia in patients with ulcerative colitis. METHODS MEDLINE, EMBASE, PubMed, and the Cochrane library were searched for studies of patients with colitis and resected polypoid dysplasia, with reports of colonoscopic follow-up and data on cancers detected. Outcomes from included articles were pooled to provide a single combined estimate of outcomes by using Poisson regression. RESULTS Of 425 articles retrieved, we analyzed data from 10 studies, comprising 376 patients with colitis and polypoid dysplasia with a combined 1704 years of follow-up. A mean of 2.8 colonoscopies were performed for each patient after the index procedure (range, 0-15 colonoscopies). The pooled incidence of cancer was 5.3 cases (95% confidence interval, 2.7-10.1 cases)/1000 years of patient follow-up. There was no evidence of heterogeneity or publication bias. The pooled rate of any dysplasia was 65 cases (95% confidence interval, 54-78 cases)/1000 patient years. CONCLUSION Patients with colitis have a low risk of colorectal cancer after resection of polypoid dysplasia; these findings support the current strategy of resection and surveillance. However, these patients have a 10-fold greater risk of developing any dysplasia than colorectal cancer and should undergo close endoscopic follow-up.

Low interobserver agreement among endoscopists in differentiating dysplastic from non-dysplastic lesions during inflammatory bowel disease colitis surveillance

Abstract Objectives. During endoscopic surveillance in patients with longstanding colitis, a variety of lesions can be encountered. Differentiation between dysplastic and non-dysplastic lesions can be challenging. The accuracy of visual endoscopic differentiation and interobserver agreement (IOA) has never been objectified. Material and methods. We assessed the accuracy of expert and nonexpert endoscopists in differentiating (low-grade) dysplastic from non-dysplastic lesions and the IOA among and between them. An online questionnaire was constructed containing 30 cases including a short medical history and an endoscopic image of a lesion found during surveillance employing chromoendoscopy. Results. A total of 17 endoscopists, 8 experts, and 9 nonexperts assessed all 30 cases. The overall sensitivity and specificity for correctly identifying dysplasia were 73.8% (95% confidence interval (CI) 62.1–85.4) and 53.8% (95% CI 42.6–64.7), respectively. Experts showed a sensitivity of 76.0% (95% CI 63.3–88.6) versus 71.8% (95% CI 58.5–85.1, p = 0.434) for nonexperts, the specificity 61.0% (95% CI 49.3–72.7) versus 47.1% (95% CI 34.6–59.5, p = 0.008). The overall IOA in differentiating between dysplastic and non-dysplastic lesions was fair 0.24 (95% CI 0.21–0.27); for experts 0.28 (95% CI 0.21–0.35) and for nonexperts 0.22 (95% CI 0.17–0.28). The overall IOA for differentiating between subtypes was fair 0.21 (95% CI 0.20–0.22); for experts 0.19 (95% CI 0.16–0.22) and nonexpert 0.23 (95% CI 0.20–0.26). Conclusion. In this image-based study, both expert and nonexpert endoscopists cannot reliably differentiate between dysplastic and non-dysplastic lesions. This emphasizes that all lesions encountered during colitis surveillance with a slight suspicion of containing dysplasia should be removed and sent for pathological assessment.

Chromoendoscopy versus autofluorescence imaging for neoplasia detection in patients with longstanding ulcerative colitis (FIND-UC): an international, multicentre, randomised controlled trial

BACKGROUND Patients with longstanding ulcerative colitis undergo regular dysplasia surveillance because they have an increased colorectal cancer risk. Autofluorescence imaging and chromoendoscopy improve dysplasia detection. The aim of this study was to determine whether autofluorescence imaging should be further studied as an alternative method for dysplasia surveillance in patients with longstanding ulcerative colitis. METHODS This prospective, international, randomised controlled trial included patients from an ulcerative colitis-dysplasia surveillance cohort from five centres in the Netherlands and the UK. Eligible patients were aged 18 years or older who were undergoing dysplasia surveillance after being diagnosed with extensive colitis (Montreal E3) at least 8 years before study start or with left-sided colitis (Montreal E2) at least 15 years before study start. Randomisation (1:1) was minimised for a previous personal history of histologically proven dysplasia and concomitant primary sclerosing cholangitis. The coprimary outcomes were the proportion of patients in whom at least one dysplastic lesion was detected and the mean number of dysplastic lesions per patient. The relative dysplasia detection rate, calculated as the ratio of the detection rates by autofluorescence imaging and chromoendoscopy, needed to be more than 0·67 (using an 80% CI) for both primary outcomes to support a subsequent large non-inferiority trial. Outcomes were analysed on a per-protocol basis. The trial is registered at the Netherlands Trial Register, number NTR4062. FINDINGS Between Aug 1, 2013, and March 10, 2017, 210 patients undergoing colonoscopy surveillance for longstanding ulcerative colitis were randomised for inspection with either autofluorescence imaging (n=105) or chromoendoscopy (n=105). Dysplasia was detected in 13 (12%) patients by autofluorescence imaging and in 20 patients (19%) by chromoendoscopy. The relative dysplasia detection rate of autofluorescence imaging versus chromoendoscopy for the proportion of patients with ulcerative colitis with at least one dysplastic lesion was 0·65 (80% CI 0·43-0·99). The mean number of detected dysplastic lesions per patient was 0·13 (SD 0·37) for autofluorescence imaging and 0·37 (1·02) for chromoendoscopy (relative dysplasia detection rate 0·36, 80% CI 0·21-0·61). Adverse events were reported for two patients in the autofluorescence imaging group (one patient had intraprocedural mild bleeding, and one patient had abdominal pain) and for three patients in the chromoendoscopy group (two patients had intraprocedural mild bleeding, and one patient had perforation). INTERPRETATION Autofluorescence imaging did not meet criteria for proceeding to a large non-inferiority trial. Therefore, existing autofluorescence imaging technology should not be further investigated as an alternative dysplasia surveillance method. FUNDING Olympus Europe and Olympus Keymed.

Quality of colonoscopy and advances in detection of colorectal lesions: a current overview

Colonoscopy is the gold standard for the detection of colorectal cancer and its precursors. Nevertheless multiple studies have demonstrated a significant miss-rate for polyps and, more importantly, demonstrated the occurrence of interval cancers in the years after colonoscopy. This imperfect protection against colorectal cancer can be explained by multiple factors related to both the endoscopist and the equipment. To ensure the quality of colonoscopy, several quality indicators have been described. These include bowel preparation, cecal intubation rate, withdrawal time, adenoma detection rate and complication rate. Measurement of these quality indicators, followed by awareness, benchmarking and additional training will hopefully optimize daily practice. If these basic quality parameters are well taken care of, advanced colonoscopic techniques will aim at further increasing the detection and differentiation of colonic lesions. In this review, the authors discuss the literature on quality indicators for colonoscopy and give a comprehensive overview of the advanced colonoscopic techniques currently available.

Diagnostic Accuracy of Endoscopic Trimodal Imaging and Chromoendoscopy for Lesion Characterization in Ulcerative Colitis

Background During surveillance colonoscopy of patients with long-standing ulcerative colitis [UC], a variety of dysplastic and non-dysplastic lesions are detected. The aim of this study was to address the diagnostic accuracy of endoscopic characterization of endoscopic trimodal imaging [ETMI] and chromoendoscopy [CE]. ETMI includes the combination of autofluorescence imaging [AFI], narrow band imaging [NBI] and white light endoscopy [WLE]. Methods This is a pre-specified additional analysis of a multi-centre, randomized controlled trial that compared AFI with CE for dysplasia detection in 210 patients with long-standing UC [FIND-UC trial]. In the AFI arm, endoscopists used the ETMI system to record AFI colour, Kudo pit pattern using NBI and WLE for lesion characterization. For AFI, purple colour and ambiguous colour combined with pit pattern type III-V on NBI was considered dysplastic. Kudo pit pattern was described in the CE arm. For pit pattern description using NBI and CE, type III-V was considered dysplastic. Histology was the reference standard. Results In total, 52 dysplastic and 255 non-dysplastic lesions were detected. Overall sensitivity for real-time prediction of dysplasia was 76.9% (95% confidence interval [CI] 46.2-95.0) for ETMI, and 81.6% [95% CI 65.7-92.3] for CE. Overall negative predictive value [NPV] for ETMI was 96.9% [95% CI 92.0-98.8] and 94.7% [90.2-97.2] for CE. Conclusions Sensitivity for endoscopic differentiation of dysplastic lesions detected during surveillance of patients with long-standing UC seems limited using ETMI and CE. Future research is warranted as the high NPV indicates that these techniques are valuable for the exclusion of dysplastic lesions [NTR4062].

981 Meta-Analysis: Cancer Risk Following Resection of Polypoid Dysplasia in Long-Standing Inflammatory Bowel Disease

G A A b st ra ct s anti-depressants/anxiolytics underscoring the impact of IBD on quality of life. Approximately 31% of IBD patients use anxiolytic drugs and 39% use anti-depressants. Conclusion: Annual IBD-related procedure charges exceed

Effects of Training and Feedback on Accuracy of Predicting Rectosigmoid Neoplastic Lesions and Selection of Surveillance Intervals by Endoscopists Performing Optical Diagnosis of Diminutive Polyps

3 billion of which estimated IFX charges are 45%. In contrast to current guidelines, long-term use of steroids was strikingly high compared to the unexpected low usage of immunosuppressive therapy. Anti-depressant/anxiolytic use is common in IBD patients. New strategies must be identified to increase and monitor adherence to guidelines in order to improve IBD care.