Narrow band imaging for detection of dysplasia in colitis: a randomized controlled trial.

OBJECTIVES: In ulcerative colitis surveillance, chromoendoscopy improves dysplasia detection 3 ­ 5-fold compared with white light endoscopy (WLE). The aim of this study was to investigate whether narrow band imaging (NBI) can improve dysplasia detection compared with WLE. METHODS: This was a randomized, parallel-group trial. A total of 220 patients were needed to be recruited to detect a threefold increase in dysplasia detection. In all, 112 patients with long-standing ulcerative colitis were randomized to colonoscopic extubation with NBI (56) or WLE (56) (1:1 ratio) at two tertiary endoscopy units in the United Kingdom. Targeted biopsies of suspicious areas and quadrantic random biopsies every 10 cm were taken in both groups. The primary outcome measure was the proportion of patients with at least one area of dysplasia detected. In a prespecified mid-point analysis, the criteria for trial discontinuation were met and the trial was stopped and analyzed at this point. RESULTS: There was no difference in the primary outcome between the two groups, with 5 patients having at least one dysplastic lesion in each group (odds ratio (OR) 1.00, 95 % confidence interval (95 % CI) 0.27 ­ 3.67, P = 1.00). This remained unchanged when adjusted for other variables (OR 0.69, 95 % CI 0.16 ­ 2.96, P = 0.62). Overall, dysplasia detection was 9 % in each arm. Yield of dysplasia from random nontargeted biopsies was 1 / 2,707 (0.04 % ). CONCLUSIONS: Overall, in this multicenter parallel-group trial, there was no difference in dysplasia detection when using NBI compared with high-definition WLE colonoscopy. Random background biopsies were ineffective in detecting dysplasia.

Development and validation of a training module on the use of narrow-band imaging in differentiation of small adenomas from hyperplastic colorectal polyps.

BACKGROUND: Experts are accurate in differentiating small adenomas from hyperplastic polyps at colonoscopy by using narrow-band imaging (NBI). OBJECTIVE: To prospectively evaluate the effectiveness of an NBI training module on individuals with varying colonoscopy experience. DESIGN: Prospective educational evaluation study. SETTING: Academic endoscopy unit. PARTICIPANTS: Twenty-one participants of varying colonoscopy experience (novices, trainees, and experienced gastroenterologists) and 5 experts in NBI. INTERVENTION: Participants completed a computer-based test module consisting of 30 NBI polyp images. No feedback was given. They then completed a computer-based training module on the use of NBI in the differentiation of adenomas and hyperplastic polyps. The test module was then completed a second time. MAIN OUTCOME MEASUREMENTS: Construct validity (the difference in baseline accuracy on the test module between different groups of participants) and content validity (difference in accuracy achieved on the test module before and after training) of the training module. RESULTS: There was a significant difference in the baseline accuracy (P < .001) between experts (0.95; 95% confidence interval [CI], 0.92-0.97), experienced colonoscopists (0.68; 95% CI, 0.68-0.74), trainees (0.75; 95% CI, 0.67-0.82), and novices (0.62; 95% CI, 0.46-0.77). Accuracy increased significantly (P < .001) for all 3 groups after training (novices 0.84; 95% CI, 0.78-0.88, trainees 0.90; 95% CI, 0.84-0.93, and experienced colonoscopists 0.84; 95% CI, 0.76-0.89). After training, the agreement was moderate at least (κ = 0.56 for novices, κ = 0.70 for trainees, and κ = 0.54 for experienced colonoscopists). LIMITATIONS: This study did not assess the accuracy of optical diagnosis in routine clinical practice. CONCLUSION: A short, computer-based training module can improve the diagnostic accuracy and interobserver agreement for the use of NBI to differentiate adenomas from hyperplastic polyps and could be used for the initial training in optical diagnosis.

Effect of a retrograde-viewing device on adenoma detection rate during colonoscopy: the TERRACE study.

BACKGROUND: Although colonoscopy is currently the optimal method for detecting colorectal polyps, some are missed. The Third Eye Retroscope provides an additional retrograde view that may detect polyps behind folds. OBJECTIVE: To determine whether the addition of the Third Eye Retroscope to colonoscopy improves the adenoma detection rate. DESIGN: Prospective, multicenter, randomized, controlled trial. SETTING: Nine European and U.S. centers. PATIENTS: Of 448 enrolled subjects, 395 had data for 2 procedures. INTERVENTIONS: Subjects underwent same-day tandem examinations with standard colonoscopy (SC) and Third Eye colonoscopy (TEC). Subjects were randomized to SC followed by TEC or TEC followed by SC. MAIN OUTCOME MEASUREMENTS: Detection rates for all polyps and adenomas with each method. RESULTS: In the per-protocol population, 173 subjects underwent SC and then TEC, and TEC yielded 78 additional polyps (48.8%), including 49 adenomas (45.8%). In 176 subjects undergoing TEC and then SC, SC yielded 31 additional polyps (19.0%), including 26 adenomas (22.6%). Net additional detection rates with TEC were 29.8% for polyps and 23.2% for adenomas. The relative risk of missing with SC compared with TEC was 2.56 for polyps (P < .001) and 1.92 for adenomas (P = .029). Mean withdrawal times for SC and TEC were 7.58 and 9.52 minutes, respectively (P < .001). The median difference in withdrawal times was 1 minute (P < .001). The mean total procedure times for SC and TEC were 16.97 and 20.87 minutes, respectively (P < .001). LIMITATIONS: Despite randomization and a large cohort, there was disparity in polyp prevalence between the 2 groups of subjects. CONCLUSION: The Third Eye Retroscope increases adenoma detection rate by visualizing areas behind folds. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01044732.).

Optical diagnosis of small colorectal polyps at routine colonoscopy (Detect InSpect ChAracterise Resect and Discard; DISCARD trial): a prospective cohort study.

BACKGROUND: Accurate optical diagnosis of small (<10 mm) colorectal polyps in vivo, without formal histopathology, could make colonoscopy more efficient and cost effective. The aim of this study was to assess whether optical diagnosis of small polyps is feasible and safe in routine clinical practice. METHODS: Consecutive patients with a positive faecal occult blood test or previous adenomas undergoing surveillance at St Mark's Hospital (London, UK), from June 19, 2008, to June 16, 2009, were included in this prospective study. Four colonoscopists with different levels of experience predicted polyp histology using optical diagnosis with high-definition white light, followed by narrow-band imaging without magnification and chromoendoscopy, as required. The primary outcome was accuracy of polyp characterisation using optical diagnosis compared with histopathology, the current gold standard. Accuracy of optical diagnosis to predict the next surveillance interval was also assessed and compared with surveillance intervals predicted by current guidelines using histopathology. This study is registered with ClinicalTrials.gov, NCT00888771. FINDINGS: 363 polyps smaller than 10 mm were detected in 130 patients, of which 278 polyps had both optical and histopathological diagnosis. By histology, 198 of these polyps were adenomas and 80 were non-neoplastic lesions (of which 62 were hyperplastic). Optical diagnosis accurately diagnosed 186 of 198 adenomas (sensitivity 0.94; 95% CI 0.90-0.97) and 55 of 62 hyperplastic polyps (specificity 0.89; 0.78-0.95), with an overall accuracy of 241 of 260 (0.93, 0.89-0.96) for polyp characterisation. Using optical diagnosis alone, 82 of 130 patients could be given a surveillance interval immediately after colonoscopy, and the same interval was found after formal histopathology in 80 patients (98%) using British guidelines and in 78 patients (95%) using US multisociety guidelines. INTERPRETATION: For polyps less than 10 mm in size, in-vivo optical diagnosis seems to be an acceptable strategy to assess polyp histopathology and future surveillance intervals. Dispensing with formal histopathology for most small polyps found at colonoscopy could improve the efficiency of the procedure and lead to substantial savings in time and cost. FUNDING: Leigh Family Trust, London, UK.

Optimising monitoring in the management of Crohn's disease: a physician's perspective.

Management of Crohn's disease has traditionally placed high value on subjective symptom assessment; however, it is increasingly appreciated that patient symptoms and objective parameters of inflammation can be disconnected. Therefore, strategies that objectively monitor inflammatory activity should be utilised throughout the disease course to optimise patient management. Initially, a thorough assessment of the severity, location and extent of disease is needed to ensure a correct diagnosis, identify any complications, help assess prognosis and select appropriate therapy. During follow-up, clinical decision-making should be driven by disease activity monitoring, with the aim of optimising treatment for tight disease control. However, few data exist to guide the choice of monitoring tools and the frequency of their use. Furthermore, adaption of monitoring strategies for symptomatic, asymptomatic and post-operative patients has not been well defined. The Annual excHangE on the ADvances in Inflammatory Bowel Disease (IBD Ahead) 2011 educational programme, which included approximately 600 gastroenterologists from 36 countries, has developed practice recommendations for the optimal monitoring of Crohn's disease based on evidence and/or expert opinion. These recommendations address the need to incorporate different modalities of disease assessment (symptom and endoscopic assessment, measurement of biomarkers of inflammatory activity and cross-sectional imaging) into robust monitoring. Furthermore, the importance of measuring and recording parameters in a standardised fashion to enable longitudinal evaluation of disease activity is highlighted.

Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup.

AIM: To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized, controlled trial data. METHODS: The Third Eye® Retroscope® Randomized Clinical Evaluation (TERRACE) was a randomized, controlled, multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope's forward view. We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device. Subjects were patients scheduled for colonoscopy for screening, surveillance or diagnostic workup, and each underwent same-day tandem examinations with standard colonoscopy (SC) and Third Eye colonoscopy (TEC), randomized to SC followed by TEC or vice versa. RESULTS: Indication for colonoscopy was screening in 176/345 subjects (51.0%), surveillance after previous polypectomy in 87 (25.2%) and diagnostic workup in 82 (23.8%). In 4 subjects no indication was specified. Previously reported overall results had shown a net additional adenoma detection rate (ADR) with TEC of 23.2% compared to SC. Relative risk (RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92 (P = 0.029). Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening, 35.7% for surveillance, 55.4% for diagnostic and 40.7% for surveillance and diagnostic combined. The RR of missing adenomas with SC vs TEC was 1.11 (P = 0.815) for screening, 3.15 (P = 0.014) for surveillance, 8.64 (P = 0.039) for diagnostic and 3.34 (P = 0.003) for surveillance and diagnostic combined. Although a multivariate Poisson regression suggested gender as a possibly significant factor, subset analysis showed that the difference between genders was not statistically significant. Age, bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC. Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm, respectively (P = NS). CONCLUSION: TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup, but not in screening patients (ClinicalTrials.gov Identifier: NCT01044732).

Non-polypoid colorectal neoplasms are relatively common worldwide.

Flat adenomas are found commonly at colonoscopy throughout the world. Similarly, small, flat submucosally invasive cancers have been described worldwide but are relatively rare, accounting for 5% to 10% of all cancers detected at colonoscopy. Although there appears to be no difference in frequency of non-polypoid colorectal neoplasms between East and West, considerable variation has been reported by individual studies, probably because of lack of consistency when defining a flat lesion. Flat elevated lesions are the most common type of flat lesion and do not appear to have a greatly increased risk of harboring invasive malignancy; however, flat lesions with depression have a significant risk of malignancy and are probably the precursor lesions for most small, flat, or ulcerating cancers.

CT colonography and non-polypoid colorectal neoplasms.

Computed tomographic colonography (CTC) has been reported to be as effective as optical colonoscopy in the detection of significant adenomas. However, there are widely conflicting performance data in relation to detection of flat neoplasia. This article describes the potential and limitations of CTC and computer-aided diagnosis in the detection of flat neoplasms.