The advent and utility of new endoscopic imaging modalities for predicting the histology of Barrett's esophagus (BE) in real time with high accuracy appear promising and could potentially obviate the need to perform random biopsies where guidelines are poorly adhered to. We embarked on evaluating the performance characteristics of white-light endoscopy with magnification (WLE-z), narrow-band imaging with magnification (NBI-z) and a combination of both modalities.This was a prospective online study with 28 endoscopists from 11 countries (Asia-Pacific region) participating as assessors. In total, 35 patients with BE were assessed using 150 slides from WLE-z and NBI-z randomly arranged using a simple classification with corresponding histology. The overall Accuracy (Acc), Sensitivity (Sn), Specificity (Sp), Positive Predictive Value (PPV), and Negative Predictive Value (NPV) of WLE-z, NBI-z and a combination of both were calculated.The overall Acc for WLE-z and NBI-z images was 87.1 % and 88.7 %, respectively. When images from the two modalities were placed side by side, the Acc increased to 90.3 %. The Sn, Sp, PPV, and NPV of WLE-z were 48 %, 92 %, 45 %, and 93 % while with NBI-z, these improved to 89 %, 89 %, 56 %, and 98 %, respectively. When both imaging modalities were viewed together, they improved further to 93 %, 90 %, 61 %, and 99 %.The high NPV (99 %) when both WLE-z and NBI-z were used simultaneously indicates that areas with regular appearance that are diagnosed with confidence can effectively be left alone and not biopsied when performed at a skilled resourced center. This approach could potentially lead to a paradigm shift of how patients with BE are assessed.
A 20-year old gentleman with a medical history of type 1 diabetes mellitus, depression and hypercholesterolemia was referred for assessment following an incidental finding of positive coeliac serology. On clinical history, the patient was asymptomatic and laboratory investigations revealed a positive tissue transglutaminase IgA antibody titre of > 100 Elisa Units (normal range: < 11) and a positive gliadin IgG antibody titre of 64 Elisa Units (normal range: < 20). He was found to be HLA-DQ2 allele positive and HLA-DQ8 allele negative. There was no evidence of anaemia with a haemoglobin level of 151 g/L (normal range 135–175) or deficiency in haematinics with a ferritin level of 370 ug/L (20–300), serum iron of 24 umol/L (8–30), transferrin of 3.15 g/L (2.00–4.00), transferrin saturation of 30% (10–55%), vitamin B12 of 360 pmol/L (140–700) and serum folate of 26.8 nmol/L (6.5–45). He had previously undergone two endoscopies that revealed normal duodenal biopsies. A repeat endoscopy was performed using a high magnification optical zoom (115X) gastroscopy scope with Narrow Band Imaging capability. Assessment of the duodenum revealed areas of patchy villous atrophy where partial to total villous atrophy can be visualised (Figure 1a) interposed with areas harbouring normal appearing villi (Figure 1b). Targeted biopsies were obtained from both these areas. Histology of the former exhibited total villous atrophy (Figure 2a) confirming the diagnosis of coeliac disease, whilst the “normal” appearing areas demonstrated normal villous morphology (Figure 2b). This case highlights this condition where patients can sometimes present with a patchy distribution of the disease, occasionally require multiple endoscopies for histological confirmation; further delaying a diagnosis which has already been delayed.
Diminutive polyps measuring ≤ 5 mm in size constitute 80% of polyps in the colon. We prospectively assessed the performance of high-definition white light endoscopy (hWLE) and narrow band imaging (NBI) in differentiating diminutive colorectal polyps.In this prospective, multicenter study, videos of 50 diminutive polyps (31 hyperplastic, 19 adenomatous) in hWLE followed by NBI (total 100 videos) were initially obtained and placed in random order into five separate folders (each folder 20 videos). Eight endoscopists were then invited to predict the histology (each endoscopist 100 videos, 800 video assessments in all). Polyps were classified into types 1-3 (hyperplastic) and type 4 (adenoma). Feedback on individual performance was given after each folder (20 videos) was assessed.The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in differentiating hyperplastic from adenomatous polyps by hWLE (400 videos) and NBI (400 videos) were 67.8%, 90.7%, 81.7%, 82.1%, and 82.0%; and 82.2%, 81.5%, 73.1%, 88.2%, and 81.8%, respectively. In the pretest and post-test analysis, the accuracy with NBI improved markedly from 68.8% to 91.3% (P = 0.001) compared with hWLE, 76.3-78.8% (P = 0.850). Overall, the interobserver agreement was 0.46 for hWLE (moderate) and 0.64 for NBI (good).NBI was as accurate as hWLE in differentiating diminutive colorectal polyps. Once a learning curve was reached, NBI achieved significantly higher accuracies with good interobserver agreement. Using a simplified classification, a didactic learning session and feedback on performance, diminutive colorectal polyps could be predicted with high accuracies with NBI.
The 2012 Digestive Disease Week (DDW; 19 – 22 May, San Diego, California, USA) received a record number of submissions on colonoscopy and colorectal cancer (CRC). Scientific presentations focused primarily on colonic polyps and can be broadly divided into polyp detection, characterization, and resection. Among the more interesting topics were the novel concept of polypectomy rate, newer-generation optical imaging technology, and advanced endoscopic resection techniques.
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