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 ... -  《-》

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 《-》

ASGE Technology Committee systematic review and meta-analysis assessing the ASGE PIVI thresholds for adopting real-time endoscopic assessment of the histology of diminutive colorectal polyps.

In vivo real-time assessment of the histology of diminutive (≤5 mm) colorectal polyps detected at colonoscopy can be achieved by means of an "optical biopsy" by using currently available endoscopic technologies. This systematic review and meta-analysis was performed by the American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee to specifically assess whether acceptable performance thresholds outlined by an ASGE Preservation and Incorporation of Valuable endoscopic Innovations (PIVI) document for clinical adoption of these technologies have been met. We conducted direct meta-analyses calculating the pooled negative predictive value (NPV) for narrow-band imaging (NBI), i-SCAN, and Fujinon Intelligent Color Enhancement (FICE)-assisted optical biopsy for predicting adenomatous polyp histology of small/diminutive colorectal polyps. We also calculated the pooled percentage agreement with histopathology when assigning postpolypectomy surveillance intervals based on combining real-time optical biopsy of colorectal polyps 5 mm or smaller with histopathologic assessment of polyps larger than 5 mm. Random-effects meta-analysis models were used. Statistical heterogeneity was evaluated by means of I(2) statistics. Our meta-analyses indicate that optical biopsy with NBI, exceeds the NPV threshold for adenomatous polyp histology, supporting a "diagnose-and-leave" strategy for diminutive predicted nonneoplastic polyps in the rectosigmoid colon. The pooled NPV of NBI for adenomatous polyp histology by using the random-effects model was 91% (95% confidence interval [CI], 88-94). This finding was associated with a high degree of heterogeneity (I(2) = 89%). Subgroup analysis indicated that the pooled NPV was greater than 90% for academic medical centers (91.8%; 95% CI, 89-94), for experts (93%; 95% CI, 91-96), and when the optical biopsy assessment was made with high confidence (93%; 95% CI, 90-96). Our meta-analyses also indicate that the agreement in assignment of postpolypectomy surveillance intervals based on optical biopsy with NBI of diminutive colorectal polyps is 90% or greater in academic settings (91%; 95% CI, 86-95), with experienced endoscopists (92%; 95% CI, 88-96) and when optical biopsy assessments are made with high confidence (91%; 95% CI, 88-95). Our systematic review and meta-analysis confirms that the thresholds established by the ASGE PIVI for real-time endoscopic assessment of the histology of diminutive polyps have been met, at least with NBI optical biopsy, with endoscopists who are expert in using this advanced imaging technology and when assessments are made with high confidence.

ASGE Technology Committee ，Abu Dayyeh BK ，Thosani N ，Konda V ，Wallace MB ，Rex DK ，Chauhan SS ，Hwang JH ，Komanduri S ，Manfredi M ，Maple JT ，Murad FM ，Siddiqui UD ，Banerjee S ... -  《-》

Is narrow band imaging superior to high-definition white light endoscopy in the assessment of diminutive colorectal polyps?

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.

Singh R ，Bhat YM ，Thurairajah PH ，Shetti MP ，Jayanna M ，Nind G ，Tam W ，Walmsey R ，Bourke M ，Moss A ，Chen R ，Bampton P ，Roberts-Thomson I ，Schoeman M ，Tucker G ... -  《-》