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Sa1555 Pathological Evaluation of Small Colorectal Polyps Resected by Cold snare Polypectomy
Abstracts
Sa1555 Pathological Evaluation of Small Colorectal Polyps Resected by Cold snare Polypectomy Takuji Kawamura*, Yasutoshi Fujii, Kojiro Nakase, Koji Uno, Kenjiro Yasuda, Kanade Katsura Kyoto Second Red Cross Hospital, Kyoto, Japan Background and Aim: Cold snare polypectomy (CSP) is a safe procedure used in the removal of small colorectal adenomatous polyps. However, several studies have suggested that in considerable number of patients, the adenomatous component would remain in the ulcer following CSP. The pathology of resected CSP specimens is not well-studied, and therefore, it is unclear whether residual adenomatous components remain in either the base or the edge of the ulcers. The aim of this study was to evaluate pathological findings, especially the lateral and base margins, of small colorectal polyps (! 10mm) resected using CSP. Patients and Methods: Between October 2013 and July 2014, we performed CSP without submucosal injection for 740 small polyps (! 10mm) in 391 patients. Resected polyps were suctioned through the scope into a trap soon after polypectomy; retrieved polyps were stuck onto a firm sponge to allow evaluation of the base and lateral margins (Figure). The specimens were cut at intervals of 2 mm after formalin fixation, and thin-section slides were prepared for microscopy using hematoxylin-eosin staining. Two pathologists made independent diagnoses based on microscopy; if the primary diagnosis differed between the 2 pathologists, the final diagnosis was made by consensus. We retrospectively analyzed the success rate of polyp retrieval, histological type of polyps, and the rate of negative lateral/base margin of the resected specimen. Results: Of the 740 resected lesions, 724 (97.8%) were successfully retrieved. The histology of the resected polyps included adenoma with low-grade dysplasia (n Z 565, 78.0%); adenoma with high-grade dysplasia (n Z 39, 5.4%); sessile serrated adenoma/polyp (n Z 80, 11.1%); hyperplastic polyp (n Z 30, 4.1%); and others (n Z 10, 1.4%). Of the 604 adenomatous polyps, piecemeal resection was performed in 21 polyps (3.5%). Of the 583 adenomatous polyps with en-block resection, the rate of negative base margins of resected specimens was 93.0% (n Z 542; 95%CI, 90.6-94.9%). In contrast, the rate of negative lateral margins was only 48.5% (n Z 283; 95%CI, 44.452.6%). Conclusions: Our data show that negative base margins could be confirmed pathologically in the majority of cases; however, the resected specimens showed a low rate of negative lateral margins. Therefore, we should pay careful attention to the edge of post-polypectomy ulcers following resection by CSP.
prediction of histology for colorectal polypoid lesions. However, NBI and magnification based diagnosis requires training and high experience. Moreover, the objective diagnosis still necessary by histology. We developed digital image processing software (DIPS) to automatically classify NBI magnifying colonoscopy images to predict the histology of polyps. We also compared the accuracy of software based and NICE classification based predictions with final histology. Patients and Methods: We gathered NBI magnifying colonoscopy images of 81 colorectal polyps undergoing endoscopic polypectomy. The stored NBI and magnified (60x) images taken before polypectomy were classified according to NICE classification by three experienced endoscopiests who were blinded to histology. Histology was used as “gold standard” reference in statistical calculations. A two-class classification was considered: non-neoplastic (hyperplastic) or neoplastic (tubular or serrated adenoma).By DIPS we analyzed the surface and vascular patterns of the polyps. After noise reduction and contrast enhancement the software identifies the extracted images of small patterns and classifies them with a Quadratic Discriminant Analysis type method according to the Kudo and Tsuruta criteria. The relative area (RA) of neoplastic type shapes was calculated finally and used to characterize the whole area. The average contrast (AC) of the prefiltered image was another image characteristic. We found by preliminary training images that non neoplastic (hyperplastic) polyps can be found at small RA or small AC values. Leave-one-out test: 85.2% precision, AUCZ0.841. The colorectal polyps were by histology: hyperplastic:57, adenoma or serrated adenoma:24. Results: The digital image processing software system yielded a detection accuracy of 87.7% (71/81) with a sensitivity of 87.3% (48/55) and specificity of 88.5% (23/26) for the diagnosis of non-neoplastic lesions in the whole data set. For diminutive polyps (% 5 mm) the DIPS method had a detection accuracy of 89.3% (25/28) and a sensitivity of 72.7% (8/11) with a specificity of 100% (17/17). For both polyp size groups DIPS and NICE classification data were comparable to predict hyperplastic histology. Table. Conclusion: Our digital image processing software is promising and reliable for predicting nonneoplastic polyp histology especially in diminutive colorectal polyps.
Non-neoplastic histology predicting data All polyps (nZ80) NICE DIPS Diminutive polyps (nZ28) 1-5 mm NICE DIPS
Sensitivity (%)
Specificity (%)
Accuracy (%)
90.9 87.3
84.6 88.5
88.9 87.7
63.6 72.7
88.2 100
78.6 89.3
Sa1557 A Randomised Controlled Trial Comparing the Modified Sano’s Versus the Nice Classifications Using Narrow Band Imaging With Near Focus Magnification in Differentiating Colorectal Polyps Sze P. Yeap*1, Rajvinder Singh1,2, Amanda Ovenden1, Andrew Ruszkiewicz1, James Y. Lau7, Rungsun Rerknimitr6, Khean Lee Goh5, Mohan Ramchandani4, Frederick Dy3, Tiing Leong Ang8, Shiaw-Hooi Ho5, Dong Wan Seo9, Hsiu-Po Wang10, Jayaram Menon11, Eng Kiong Teo8, Evan G. Ong12, Philip W. Chiu7, Hwoon-Yong Jung9, Ching-Tai Lee13 1 The Lyell McEwin Hospital, Elizabeth Vale, SA, Australia; 2University of Adelaide, Adelaide, SA, Australia; 3University of Santo Tomas Hospital, Metro Manila, Philippines; 4Asian Institute of Gastroenterology, Hyderabad, India; 5University Malaya Medical Centre, Kuala Lumpur, Malaysia; 6Chulalongkorn University, Bangkok, Thailand; 7Prince of Wales Hospital, New Territories, Hong Kong; 8Changi General Hospital, Simei, Singapore; 9Asian Medical Centre, Seoul, Korea (the Republic of); 10 National Taiwan University Hospital, Taipei, Taiwan; 11Queen Elizabeth Hospital, Sabah, Malaysia; 12Metropolitan Hospital, Manila, Philippines; 13E-Da Hospital, Kaohsiung, Taiwan
Sa1556 Digital Image Processing Software for Predicting the Histology of Small Colorectal Polyps by Using Narrow-Band Imaging Magnifying Colonoscopy István Rácz*1, András Horváth2, Milán Szalai1, Szabolcs Spindler2, Gyöngyi Kiss1, Henriett Regöczi1, Zoltán Horváth2 1 Petz Aladár County and Teaching Hospital, Gy} or, Hungary; 2Széchenyi University, Gy} or, Hungary Background: Narrow-band imaging (NBI) evaluation of colorectal polyps using the NBI International Colorectal Endoscopic (NICE) classification is clinically useful in
www.giejournal.org
Introduction: Majority of the polyps found during screening colonoscopy are small and benign but current practice still requires costly pathological interpretation. Advances in endoscopic imaging have prompted consideration of real-time diagnosis of colorectal polyps which maybe more cost-effective. We aim to assess the utility of Modified Sano’s versus NICE classification in differentiating colorectal polyps using the Narrow Band Imaging system with near focus function (NBI-NF) in this international prospective multicentre randomised study. Methods: Consecutive patients undergoing colonoscopy for any indication between June 2013 to October 2014 were recruited. All procedures were performed using the 190 series Exera III system (Olympus Co. Ltd, Japan). Based on the validated Modified Sano’s or NICE classification, real time diagnosis was made on polyps that were detected. Each patient was randomized to have the prediction of polyps (high or low level of confidence) with either of these classifications but not both. This was followed by biopsies, endoscopic or surgical resection. The diagnosis was then compared to the final blinded histopathology analysis. The primary endpoint was the predicted
Volume 81, No. 5S : 2015 GASTROINTESTINAL ENDOSCOPY AB259
Sa1555 Pathological Evaluation of Small Colorectal Polyps Resected by Cold snare Polypectomy Takuji Kawamura*, Yasutoshi Fujii, Kojiro Nakase, Koji Uno, Kenjiro Yasuda, Kanade Katsura Kyoto Second Red Cross Hospital, Kyoto, Japan Background and Aim: Cold snare polypectomy (CSP) is a safe procedure used in the removal of small colorectal adenomatous polyps. However, several studies have suggested that in considerable number of patients, the adenomatous component would remain in the ulcer following CSP. The pathology of resected CSP specimens is not well-studied, and therefore, it is unclear whether residual adenomatous components remain in either the base or the edge of the ulcers. The aim of this study was to evaluate pathological findings, especially the lateral and base margins, of small colorectal polyps (! 10mm) resected using CSP. Patients and Methods: Between October 2013 and July 2014, we performed CSP without submucosal injection for 740 small polyps (! 10mm) in 391 patients. Resected polyps were suctioned through the scope into a trap soon after polypectomy; retrieved polyps were stuck onto a firm sponge to allow evaluation of the base and lateral margins (Figure). The specimens were cut at intervals of 2 mm after formalin fixation, and thin-section slides were prepared for microscopy using hematoxylin-eosin staining. Two pathologists made independent diagnoses based on microscopy; if the primary diagnosis differed between the 2 pathologists, the final diagnosis was made by consensus. We retrospectively analyzed the success rate of polyp retrieval, histological type of polyps, and the rate of negative lateral/base margin of the resected specimen. Results: Of the 740 resected lesions, 724 (97.8%) were successfully retrieved. The histology of the resected polyps included adenoma with low-grade dysplasia (n Z 565, 78.0%); adenoma with high-grade dysplasia (n Z 39, 5.4%); sessile serrated adenoma/polyp (n Z 80, 11.1%); hyperplastic polyp (n Z 30, 4.1%); and others (n Z 10, 1.4%). Of the 604 adenomatous polyps, piecemeal resection was performed in 21 polyps (3.5%). Of the 583 adenomatous polyps with en-block resection, the rate of negative base margins of resected specimens was 93.0% (n Z 542; 95%CI, 90.6-94.9%). In contrast, the rate of negative lateral margins was only 48.5% (n Z 283; 95%CI, 44.452.6%). Conclusions: Our data show that negative base margins could be confirmed pathologically in the majority of cases; however, the resected specimens showed a low rate of negative lateral margins. Therefore, we should pay careful attention to the edge of post-polypectomy ulcers following resection by CSP.
prediction of histology for colorectal polypoid lesions. However, NBI and magnification based diagnosis requires training and high experience. Moreover, the objective diagnosis still necessary by histology. We developed digital image processing software (DIPS) to automatically classify NBI magnifying colonoscopy images to predict the histology of polyps. We also compared the accuracy of software based and NICE classification based predictions with final histology. Patients and Methods: We gathered NBI magnifying colonoscopy images of 81 colorectal polyps undergoing endoscopic polypectomy. The stored NBI and magnified (60x) images taken before polypectomy were classified according to NICE classification by three experienced endoscopiests who were blinded to histology. Histology was used as “gold standard” reference in statistical calculations. A two-class classification was considered: non-neoplastic (hyperplastic) or neoplastic (tubular or serrated adenoma).By DIPS we analyzed the surface and vascular patterns of the polyps. After noise reduction and contrast enhancement the software identifies the extracted images of small patterns and classifies them with a Quadratic Discriminant Analysis type method according to the Kudo and Tsuruta criteria. The relative area (RA) of neoplastic type shapes was calculated finally and used to characterize the whole area. The average contrast (AC) of the prefiltered image was another image characteristic. We found by preliminary training images that non neoplastic (hyperplastic) polyps can be found at small RA or small AC values. Leave-one-out test: 85.2% precision, AUCZ0.841. The colorectal polyps were by histology: hyperplastic:57, adenoma or serrated adenoma:24. Results: The digital image processing software system yielded a detection accuracy of 87.7% (71/81) with a sensitivity of 87.3% (48/55) and specificity of 88.5% (23/26) for the diagnosis of non-neoplastic lesions in the whole data set. For diminutive polyps (% 5 mm) the DIPS method had a detection accuracy of 89.3% (25/28) and a sensitivity of 72.7% (8/11) with a specificity of 100% (17/17). For both polyp size groups DIPS and NICE classification data were comparable to predict hyperplastic histology. Table. Conclusion: Our digital image processing software is promising and reliable for predicting nonneoplastic polyp histology especially in diminutive colorectal polyps.
Non-neoplastic histology predicting data All polyps (nZ80) NICE DIPS Diminutive polyps (nZ28) 1-5 mm NICE DIPS
Sensitivity (%)
Specificity (%)
Accuracy (%)
90.9 87.3
84.6 88.5
88.9 87.7
63.6 72.7
88.2 100
78.6 89.3
Sa1557 A Randomised Controlled Trial Comparing the Modified Sano’s Versus the Nice Classifications Using Narrow Band Imaging With Near Focus Magnification in Differentiating Colorectal Polyps Sze P. Yeap*1, Rajvinder Singh1,2, Amanda Ovenden1, Andrew Ruszkiewicz1, James Y. Lau7, Rungsun Rerknimitr6, Khean Lee Goh5, Mohan Ramchandani4, Frederick Dy3, Tiing Leong Ang8, Shiaw-Hooi Ho5, Dong Wan Seo9, Hsiu-Po Wang10, Jayaram Menon11, Eng Kiong Teo8, Evan G. Ong12, Philip W. Chiu7, Hwoon-Yong Jung9, Ching-Tai Lee13 1 The Lyell McEwin Hospital, Elizabeth Vale, SA, Australia; 2University of Adelaide, Adelaide, SA, Australia; 3University of Santo Tomas Hospital, Metro Manila, Philippines; 4Asian Institute of Gastroenterology, Hyderabad, India; 5University Malaya Medical Centre, Kuala Lumpur, Malaysia; 6Chulalongkorn University, Bangkok, Thailand; 7Prince of Wales Hospital, New Territories, Hong Kong; 8Changi General Hospital, Simei, Singapore; 9Asian Medical Centre, Seoul, Korea (the Republic of); 10 National Taiwan University Hospital, Taipei, Taiwan; 11Queen Elizabeth Hospital, Sabah, Malaysia; 12Metropolitan Hospital, Manila, Philippines; 13E-Da Hospital, Kaohsiung, Taiwan
Sa1556 Digital Image Processing Software for Predicting the Histology of Small Colorectal Polyps by Using Narrow-Band Imaging Magnifying Colonoscopy István Rácz*1, András Horváth2, Milán Szalai1, Szabolcs Spindler2, Gyöngyi Kiss1, Henriett Regöczi1, Zoltán Horváth2 1 Petz Aladár County and Teaching Hospital, Gy} or, Hungary; 2Széchenyi University, Gy} or, Hungary Background: Narrow-band imaging (NBI) evaluation of colorectal polyps using the NBI International Colorectal Endoscopic (NICE) classification is clinically useful in
www.giejournal.org
Introduction: Majority of the polyps found during screening colonoscopy are small and benign but current practice still requires costly pathological interpretation. Advances in endoscopic imaging have prompted consideration of real-time diagnosis of colorectal polyps which maybe more cost-effective. We aim to assess the utility of Modified Sano’s versus NICE classification in differentiating colorectal polyps using the Narrow Band Imaging system with near focus function (NBI-NF) in this international prospective multicentre randomised study. Methods: Consecutive patients undergoing colonoscopy for any indication between June 2013 to October 2014 were recruited. All procedures were performed using the 190 series Exera III system (Olympus Co. Ltd, Japan). Based on the validated Modified Sano’s or NICE classification, real time diagnosis was made on polyps that were detected. Each patient was randomized to have the prediction of polyps (high or low level of confidence) with either of these classifications but not both. This was followed by biopsies, endoscopic or surgical resection. The diagnosis was then compared to the final blinded histopathology analysis. The primary endpoint was the predicted
Volume 81, No. 5S : 2015 GASTROINTESTINAL ENDOSCOPY AB259