A prospective dual-center proof-of-principle study evaluating the incremental benefit of narrow-band imaging with a fixed zoom function in real-time prediction of polyp histology. Can we resect and discard?

Advancements in endoscopic technology have increased the ability to distinguish neoplastic polyps during colonoscopy. If a minimum accuracy can be achieved, then a resect-and-discard model can be implemented, although studies to date have demonstrated limited success, especially in the assessment of serrated polyps. To perform a proof-of-principle study assessing the accuracy of narrow-band imaging with near focus in predicting polyp histology including serrated polyps and to determine whether the minimum requirements can be achieved for a resect-and-discard policy. Dual-center, prospective case series. Two tertiary-care referral endoscopic centers in Australia. Two hundred consecutive patients undergoing colonoscopy for routine indications were recruited. Any polyps identified were assessed by using standard white light followed by narrow-band imaging with near focus for Kudo pit patterns and modified Sano capillary patterns. Based on this assessment and the macroscopic appearance, the polyp histology was predicted and subsequently compared with histopathology results. Correlation in postpolypectomy surveillance intervals between endoscopic and pathologic assessments as well as negative predictive value for rectosigmoid hyperplastic polyps. There was a 96% agreement for surveillance intervals between endoscopic assessment and histology by using the American Society for Gastrointestinal Endoscopy guidelines. There was a 96% negative predictive value in assessing rectosigmoid hyperplastic polyps. Because this was a proof-of-principle study, there was no control arm, and there were small numbers, especially in assessing subgroups. The results have limited generalizability with the training requirements for polyp recognition, with confidence to be determined. Narrow-band imaging with near focus can predict polyp histology (including serrated polyps) accurately in the hands of trained endoscopists. Further studies with larger numbers are required to further validate this practice.

Kuruvilla N ，Paramsothy R ，Gill R ，Selby WS ，Remedios ML ，Kaffes AJ ... -  《-》

Accuracy of narrow-band imaging in predicting colonoscopy surveillance intervals and histology of distal diminutive polyps: results from a multicenter, prospective trial.

In vivo prediction of colorectal polyp histology by narrow-band imaging (NBI) could potentially avoid post-polypectomy histologic examination or resection of diminutive lesions, thereby reducing costs and risk. To assess whether NBI is able to predict colonoscopy surveillance intervals and histology of distal diminutive polyps according to American Society for Gastrointestinal Endoscopy (ASGE) criteria. Prospective, multicenter study. Five endoscopic centers. Consecutive patients undergoing colonoscopy in 5 centers were included. Participating endoscopists were required to pass a before-study qualifying examination. Histology of polyps that were <10 mm was predicted at NBI and assigned a designation of high or low confidence. Accuracy of high-confidence NBI prediction for polyps ≤5 mm in predicting surveillance intervals and negative predictive value (NPV) for adenomatous histology in the rectosigmoid colon were compared with the ASGE thresholds (90% agreement, 90% NPV). A total of 278 patients (mean age, 63 years; 58% male) were enrolled. At colonoscopy, 574 (97.3%) polyps <10 mm (429 ≤5 mm, 60% adenomatous) were retrieved for histologic analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of high confidence-NBI predictions for adenomatous histology in lesions ≤5 mm were 90%, 88%, 89%, 89%, and 89%, respectively. High-confidence characterization of polyps ≤5 mm predicted the correct surveillance interval in 92% to 99% of cases, according to the American and European guidelines. NPV of high-confidence NBI for adenomatous histology for the rectosigmoid colon lesions ≤5 mm was 92%. Only experienced endoscopists were included. High-confidence prediction of histology for polyps ≤5 mm appears to be sufficiently accurate to avoid post-polypectomy histologic examination of the resected lesions as well as to allow rectosigmoid hyperplastic polyps to be left in place without resection. ( NCT01675752.).

Repici A ，Hassan C ，Radaelli F ，Occhipinti P ，De Angelis C ，Romeo F ，Paggi S ，Saettone S ，Cisarò F ，Spaander M ，Sharma P ，Kuipers EJ ... -  《-》

Leaving distal colorectal hyperplastic polyps in place can be achieved with high accuracy by using narrow-band imaging: an observational study.

Accurate colonoscopic assessment of colorectal polyp histology could avoid resection of distal nonadenomatous polyps and reduce costs and risk. To assess the accuracy of predicting histology by using narrow-band imaging (NBI) in real time for distal colorectal polyps. Prospective observational study. University hospital and ambulatory surgery center. This study involved 225 consecutive adults undergoing elective screening or surveillance colonoscopy. We evaluated real-time histology of 235 distal (rectosigmoid) colorectal polyps from 31 patients by using high-definition colonoscopy and NBI without optical magnification. For each polyp, the endoscopist described size, Paris classification, and surface characteristics (vascular and pit pattern, color, pseudodepression). Before resection, histology was predicted, and a level of confidence (high or low) was assigned. Sensitivity and negative predictive value of high-confidence endoscopic predictions of adenomatous versus hyperplastic histology for polyps ≤ 5 mm. The accuracy of a high-confidence endoscopic prediction was 97.7%, sensitivity for adenomatous histology 93.9%, specificity 98.4%, negative predictive value 97.9%, and positive predictive value 75.6%. The performance characteristics for predicting diminutive distal polyps (≤ 5 mm) with high confidence were sensitivity 96.0%, specificity 99.4%, negative predictive value 99.4%, and positive predictive value 96.0%. Single-center study with a single endoscopist. NBI without optical magnification is sufficiently accurate to allow distal hyperplastic polyps to be left in place without resection and small, distal adenomas to be discarded without pathologic assessment. These findings validate NBI criteria based on color, vessels, and pit characteristics for predicting real-time colorectal polyp histology.

Hewett DG ，Huffman ME ，Rex DK 《-》

Real-Time Characterization of Diminutive Colorectal Polyp Histology Using Narrow-Band Imaging: Implications for the Resect and Discard Strategy.

Narrow-band imaging (NBI) allows real-time histologic classification of colorectal polyps. We investigated whether endoscopists without prior training in NBI can achieve the following thresholds recommended by the American Society for Gastrointestinal Endoscopy: for diminutive colorectal polyps characterized with high confidence, a ≥90% negative predictive value for adenomas in the rectosigmoid and a ≥90% agreement in surveillance intervals. Twenty-six endoscopists from 2 tertiary care centers underwent standardized training in NBI interpretation. Endoscopists made real-time predictions of diminutive colorectal polyp histology and surveillance interval predictions based on NBI. Their performance was evaluated by comparing predicted with actual findings from histologic analysis. Multilevel logistic regression was used to assess predictors of performance. Cumulative summation analysis was used to characterize learning curves. The endoscopists performed 1451 colonoscopies and made 3012 diminutive polyp predictions (74.3% high confidence) using NBI. They made 898 immediate post-procedure surveillance interval predictions. An additional 505 surveillance intervals were determined with histology input. The overall negative predictive value for high-confidence characterizations in the rectosigmoid was 94.7% (95% confidence interval: 92.6%-96.8%) and the surveillance interval agreement was 91.2% (95% confidence interval: 89.7%-92.7%). Overall, 97.0% of surveillance interval predictions would have brought patients back on time or early. High-confidence characterization was the strongest predictor of accuracy (odds ratio = 3.42; 95% confidence interval: 2.72-4.29; P < .001). Performance improved over time, however, according to cumulative summation analysis, only 7 participants (26.9%) identified adenomas with sufficient sensitivity such that further auditing is not required. With standardized training, gastroenterologists without prior expertise in NBI were able to meet the negative predictive value and surveillance interval thresholds set forth by the American Society for Gastrointestinal Endoscopy. The majority of disagreement in surveillance interval brought patients back early. Performance improves with time, but most endoscopists will require ongoing auditing of performance. ClinicalTrials.gov ID NCT02441998.

Patel SG ，Schoenfeld P ，Kim HM ，Ward EK ，Bansal A ，Kim Y ，Hosford L ，Myers A ，Foster S ，Craft J ，Shopinski S ，Wilson RH ，Ahnen DJ ，Rastogi A ，Wani S ... -  《-》

Accuracy of in vivo colorectal polyp discrimination by using dual-focus high-definition narrow-band imaging colonoscopy.

Discriminating neoplastic from non-neoplastic polyps can significantly reduce the cost of colonoscopy. The American Society for Gastrointestinal Endoscopy (ASGE) recently set threshold levels for optical diagnostic accuracy to be acceptable for clinical use. In this study, we compare a novel colonoscope capable of dual-focus imaging with standard colonoscopy with respect to the ASGE guidelines. An academic medical center ambulatory surgical center. Patients at average risk were randomized to standard colonoscopy (Olympus CF-H180 and Exera II 180 colonoscopes, Olympus America, Center Valley, Pa) or dual-focus colonoscopy (Olympus CF-HQ190 and Exera III 190 colonoscopes, Olympus America). All polyps were given an optical diagnosis and compared with histology. A total of 600 patients were consented and 522 completed all aspects of the procedure. A total of 927 polyps were analyzed. Optical diagnostic accuracy was 79% (95% confidence interval, 74%-83%) for the 190 and 77% (95% confidence interval, 73%-81%) for the 180 colonoscope. Adenoma detection rates were also similar between the 2 groups (50% for the 190 vs 52% for the 180 colonoscope). For small distal rectosigmoid polyps with a high confidence diagnosis, the negative predictive value for adenoma was 96% (range 89%-99%) for the 180 in the narrow-band imaging (NBI) mode and 97% (range 88%-99%) for the 190 colonoscope in NBI mode. Agreement of surveillance intervals by using optical diagnosis was 94% to 95% for all modalities (180 and 190 colonoscopes, white light imaging, NBI). Our study evaluated the accuracy of the 180 and 190 colonoscopes at a center with already-established expertise in endoscopic imaging. Both traditional and new dual-focus colonoscopes provide highly accurate optical polyp discrimination. There was no difference between the 2 systems in terms of discrimination or adenoma detection. Both systems are consistent with ASGE guidelines for optical diagnosis of selected colorectal polyps without histological confirmation.

Wallace MB ，Crook JE ，Coe S ，Ussui V ，Staggs E ，Almansa C ，Patel MK ，Bouras E ，Cangemi J ，Keaveny A ，Picco M ，Riegert-Johnson D ... -  《-》