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Tu1445 Computerized, Image Analysis of Diminutive Polyps During Colonoscopy - Preliminary Results of a Feasibility Study
Abstracts
diminutive polyps if the prediction for surveillance intervals is accurate in R90%, because the prevalence of advanced adenomas in diminutive polyps was very low (approximately 1%) in previous studies. However, NICE classification cannot distinguish between advanced and non-advanced lesions. Methods: In this study we assessed prevalence of advanced adenomas in small (5-10 mm) and diminutive (!0.5 mm) polyps within 110.405 screening colonoscopies performed within a nationwide quality assurance program in Austria between November 2007 and June 2013. Results: 68.6% (nZ23.097) of polpys ! 10mm (nZ33.674) were diminutive and 31.4% (nZ10.577) were small polyps. 39.2% (nZ9.060) of the diminutive lesions were located in the proximal colon and 60.8% (nZ14.037) in the distal colon. Small polyps were in 49.6% (nZ5.245) located in the proximal and in 50.4% (nZ5.332) in the distal colon. In the proximal colon diminutive respectively small polyps were in 5.7% and 14.8% advanced adenomas, in 49.1% and 57.6% adenomas, in 43.5% and 34.5% hyperplastic and in 0.9% and 1.6% serrated lesions. In the distal colon diminutive respectively small polyps were in 4.1% and 15.4% advanced adenomas, in 27.3% and 51.2% adenomas, in 67.4% and 41.3% hyperplastic and in 0.4% and 0.6% serrated lesions. Conclusion: Data of our study showed a higher prevalence of advanced adenomas in diminutive and small lesions than reported in previous studies. Approximately every second polyp in the proximal and 67% of polyps in the distal colon were hyperplastic. Every 18th polyp in the proximal and every 24th polyp in the distal colon had advanced features. Since recommendations for resect and discard strategy is based on prevalence of histological features, this issue has to be addressed especially in large screening cohorts before establishing resect and discard in everyday clinical practice since advanced lesions in small and diminutive polyps might be underestimated.
Tu1445 Computerized, Image Analysis of Diminutive Polyps During Colonoscopy - Preliminary Results of a Feasibility Study Amir Klein*1, Elizabeth E. Half1, Yehuda Chowers1, Matti Waterman1, Halim Awadie1, Edmond Sabo2 1 Gastroenterology, Rambam health care campus, Haifa, Israel; 2 Pathology, Rambam health care campus, Haifa, Israel Background: Diminutive polyps (DP) constitute the majority of polyps detected during colonoscopy and rarely harbor advanced histology. Resecting and submitting these low-risk lesions to pathology is time and money consuming however serves the purpose of knowing whether they are adenomas and determines surveillance interval recommendations. It has been suggested that an endoscopic diagnosis of polyp histology and foregoing the pathological examination of DPs may save over 1 billion dollar/yr in the USA alone. Computerized image analysis (CIA) has the potential to analyze an image with significantly greater detail and accuracy than the human eye and is less likely to suffer from inter and intra-observer variability. Aim: To evaluate weather CIA of endoscopic images of DPs can accurately classify polyps as neoplastic or hyperplastic compared to the final histopathologic diagnosis. Methods: Patients undergoing colonoscopy who had a DP detected and removed were included in the study. White light and NBI images were obtained prior to polypectomy. Real time, endoscopic classification of the polyps was based on the Kudo classification of pit-pattern and the NICE criteria. Polyp images were then analyzed using CIA and compared to final histopathological diagnosis. Data analysis was performed using multivariate regression models and discriminant score (DS) computations. Results: Twenty DPs were analyzed. Image analysis included variables of optical densities, texture and image complexity. In multivariate analysis of NBI images, image complexity and optical density were found to be independent predictors for accurately differentiating between adenomatous and hyperplastic polyps with a sensitivity of 91% and specificity of 62.5%. On cross validation, a sensitivity of 82.5% and a specificity of 62.5% were obtained. ROC analysis of the discriminant score revealed an area under the curve (AUC) of 0.80 (CI 0.660.94). A DS of -3.57 or lower had a sensitivity of 96% for identifying an adenoma (nZ9), and a DS of 2.59 or higher, had a specificity of 100% for identifying a hyperplastic polyp (nZ7). Image analysis of white light images, did not reveal a statistically significant difference between the groups. The real time endoscopic assessment correctly classified adenomas with a low sensitivity of 59%. Conclusions: In this pilot study, CIA, enabled correct classification of DPs as adenomas, with a sensitivity of 91%, a specificity of 62.5% and an overall accuracy of 80%. In addition, CIA was more accurate in predicting the pathological diagnosis than the endoscopists assessment. Future automation and integration of this tool into real-time endoscopy may prove both clinically valuable and cost-effective in the management of DPs.
www.giejournal.org
Tu1446 Efficacy and Safety of a New Polypectomy SNARE for ColdPolypectomy of Subcentimetric Colorectal Polyps: the E-Scope (Efficacy and Safety of Cold Polypectomy) Trial Alessandro Repici*1, Giuseppe Strangio1, Manol Jovani1, Cesare Hassan2, Andrea Anderloni1, Silvia Carrara1, Camilla Ciscato1, Chiara Genco1, Marco Massidda1, ELISA Chiara Ferrara1, Alessandra Carlino1, Pietro Occhipinti3, Marco Dinelli4, Franco Radaelli5, Alberto Malesci1 1 Gastroenterology Digestive Endoscopy Service, Humanitas Research Hospital, Rozzano, Milano, Italy; 2Gastroenterology, Nuovo Regina Margherita Hospital, Roma, Italy; 3Gastroenterology and Digestive Endoscopy, Borgomanero Hospital, Novara, Italy; 4Digestive Endoscopy, San Gerardo Hospital, Monza, Italy; 5Gastroenterology and Digestive Endoscopy, Valducce Hospital, Como, Italy Background & Aims: With regard to the efficacy of cold-polypectomy for subcentimetric polyps, no study has actually assessed the post-polypectomy completeness of the removal of polyp tissue (i.e. residual disease). On the other hand, the efficacy of an alternative method to remove diminutive polyps (i.e.!5 mm), i.e. with biopsy forceps, has been shown to be suboptimal. The purpose of the study was to evaluate the efficacy and safety of cold-polypectomy performed using a new device purposely developed for the removal of subcentimetric colorectal polyps (with a braided snare wire that is 33% thinner than traditional braided wires). Methods: Consecutive patients presenting at colonoscopy in 3 centers with at least one !10 mm polyp were included in the study, irrespectively of the presence of O10 mm lesions. Clinical success was defined as absence of polyp tissue, either hyperplastic or adenomatous, on the area of cold-polypectomy of subcentimetric polyps. Such assessment was performed on two biopsies performed on the polypectomy scar immediately after polyp removal. Post-polypectomy bleeding has been defined as any bleeding requiring immediate therapeutic endoscopic procedure or delayed treatment within 30 days from the index procedure. Results: Of 172 polyps (120 patients; 60.0% men; mean age, 64 years), 52 (30%) and 120 (70%) were !5 mm and 6-9 mm, respectively, and 144 (84%) were adenomatous. Post-cold-polypectomy biopsies revealed that only 6/172 (3.4%) subcentimetric polyps (4 adenomatous and 2 hyperplastic) were incompletely removed, corresponding to a complete resection rate of 96.6% (95% CI: 93%-98%), without difference between !5 mm and 6-9 mm categories. Two cases (1.1%) of early post-polypectomy bleeding occurred and were successfully treated with clip application. Conclusions: Cold-snare polypectomy with the new device appears to be highly effective and safe for the removal of subcentimetric polyps.
Tu1447 Endoscopic Over-Estimation of Polyp Size and Factors Influencing Degree of Bias Bradley W. Anderson*1, Thomas C. Smyrk2, Seth R. Sweetser1, Douglas W. Mahoney3, Kari S. Anderson3, Mary E. Devens1, John B. Kisiel1, David a. Ahlquist1 1 Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN; 2 Anatomic Pathology, Mayo Clinic, Rochester, MN; 3Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN Background: Polyp size strongly leverages colorectal cancer (CRC) surveillance recommendations, yet this parameter is based on subjective endoscopic estimates. Such estimates are of paramount importance, as both adenomas or sessile serrated polyps (SSPs) R1 cm are considered "advanced" and are assigned more frequent surveillance than are smaller lesions. Several prior reports suggest that endoscopists tend to over-estimate colorectal polyp size, but these studies have been relatively small with limited assessment of co-variates. Aims: Based on current practice outcomes, we sought to (1) compare assessments of polyp size between endoscopic estimation and pathology measurement and 2) evaluate factors that influence endoscopic estimation bias. Methods: Colonoscopy and pathology reports were reviewed from electronic medical records at Mayo Clinic in Rochester MN. Data were limited to the year 2012 to reflect current state of practice. Only those polyps resected in toto with both endoscopic estimation and pathology measurement recorded were included for analyses. Pathology-based measurements were considered as the criterion standard for comparison given their ex vivo ruler-based appraisal. Results: From 6067 colorectal polyps resected during the study period, 1528 met above inclusion criteria. Distribution of polyp size estimated by endoscopy revealed modal clustering, particularly around 1 cm (Fig.1a), in contrast to the smooth distribution continuum by pathology measurement (Fig.1b). Of the 222 polyps estimated as R1 cm on endoscopy, 46% were over-called (! 1 cm on pathology); while of the 1306 polyps estimated as !1cm, 3.9% were under-called (R1cm on pathology). Among the 99 polyps called 1 cm on endoscopy, 72% were !1cm on pathology, 8.1% equal to 1cm, and 20% O1 cm. The extent of endoscopic overestimation increased in proportion to polyp size. By histology, 39% of adenomas, 59% of SSPs, and 73% of hyperplastic polyps (HPs) were over-called, pZ0.008. By
Volume 79, No. 5S : 2014 GASTROINTESTINAL ENDOSCOPY AB435
diminutive polyps if the prediction for surveillance intervals is accurate in R90%, because the prevalence of advanced adenomas in diminutive polyps was very low (approximately 1%) in previous studies. However, NICE classification cannot distinguish between advanced and non-advanced lesions. Methods: In this study we assessed prevalence of advanced adenomas in small (5-10 mm) and diminutive (!0.5 mm) polyps within 110.405 screening colonoscopies performed within a nationwide quality assurance program in Austria between November 2007 and June 2013. Results: 68.6% (nZ23.097) of polpys ! 10mm (nZ33.674) were diminutive and 31.4% (nZ10.577) were small polyps. 39.2% (nZ9.060) of the diminutive lesions were located in the proximal colon and 60.8% (nZ14.037) in the distal colon. Small polyps were in 49.6% (nZ5.245) located in the proximal and in 50.4% (nZ5.332) in the distal colon. In the proximal colon diminutive respectively small polyps were in 5.7% and 14.8% advanced adenomas, in 49.1% and 57.6% adenomas, in 43.5% and 34.5% hyperplastic and in 0.9% and 1.6% serrated lesions. In the distal colon diminutive respectively small polyps were in 4.1% and 15.4% advanced adenomas, in 27.3% and 51.2% adenomas, in 67.4% and 41.3% hyperplastic and in 0.4% and 0.6% serrated lesions. Conclusion: Data of our study showed a higher prevalence of advanced adenomas in diminutive and small lesions than reported in previous studies. Approximately every second polyp in the proximal and 67% of polyps in the distal colon were hyperplastic. Every 18th polyp in the proximal and every 24th polyp in the distal colon had advanced features. Since recommendations for resect and discard strategy is based on prevalence of histological features, this issue has to be addressed especially in large screening cohorts before establishing resect and discard in everyday clinical practice since advanced lesions in small and diminutive polyps might be underestimated.
Tu1445 Computerized, Image Analysis of Diminutive Polyps During Colonoscopy - Preliminary Results of a Feasibility Study Amir Klein*1, Elizabeth E. Half1, Yehuda Chowers1, Matti Waterman1, Halim Awadie1, Edmond Sabo2 1 Gastroenterology, Rambam health care campus, Haifa, Israel; 2 Pathology, Rambam health care campus, Haifa, Israel Background: Diminutive polyps (DP) constitute the majority of polyps detected during colonoscopy and rarely harbor advanced histology. Resecting and submitting these low-risk lesions to pathology is time and money consuming however serves the purpose of knowing whether they are adenomas and determines surveillance interval recommendations. It has been suggested that an endoscopic diagnosis of polyp histology and foregoing the pathological examination of DPs may save over 1 billion dollar/yr in the USA alone. Computerized image analysis (CIA) has the potential to analyze an image with significantly greater detail and accuracy than the human eye and is less likely to suffer from inter and intra-observer variability. Aim: To evaluate weather CIA of endoscopic images of DPs can accurately classify polyps as neoplastic or hyperplastic compared to the final histopathologic diagnosis. Methods: Patients undergoing colonoscopy who had a DP detected and removed were included in the study. White light and NBI images were obtained prior to polypectomy. Real time, endoscopic classification of the polyps was based on the Kudo classification of pit-pattern and the NICE criteria. Polyp images were then analyzed using CIA and compared to final histopathological diagnosis. Data analysis was performed using multivariate regression models and discriminant score (DS) computations. Results: Twenty DPs were analyzed. Image analysis included variables of optical densities, texture and image complexity. In multivariate analysis of NBI images, image complexity and optical density were found to be independent predictors for accurately differentiating between adenomatous and hyperplastic polyps with a sensitivity of 91% and specificity of 62.5%. On cross validation, a sensitivity of 82.5% and a specificity of 62.5% were obtained. ROC analysis of the discriminant score revealed an area under the curve (AUC) of 0.80 (CI 0.660.94). A DS of -3.57 or lower had a sensitivity of 96% for identifying an adenoma (nZ9), and a DS of 2.59 or higher, had a specificity of 100% for identifying a hyperplastic polyp (nZ7). Image analysis of white light images, did not reveal a statistically significant difference between the groups. The real time endoscopic assessment correctly classified adenomas with a low sensitivity of 59%. Conclusions: In this pilot study, CIA, enabled correct classification of DPs as adenomas, with a sensitivity of 91%, a specificity of 62.5% and an overall accuracy of 80%. In addition, CIA was more accurate in predicting the pathological diagnosis than the endoscopists assessment. Future automation and integration of this tool into real-time endoscopy may prove both clinically valuable and cost-effective in the management of DPs.
www.giejournal.org
Tu1446 Efficacy and Safety of a New Polypectomy SNARE for ColdPolypectomy of Subcentimetric Colorectal Polyps: the E-Scope (Efficacy and Safety of Cold Polypectomy) Trial Alessandro Repici*1, Giuseppe Strangio1, Manol Jovani1, Cesare Hassan2, Andrea Anderloni1, Silvia Carrara1, Camilla Ciscato1, Chiara Genco1, Marco Massidda1, ELISA Chiara Ferrara1, Alessandra Carlino1, Pietro Occhipinti3, Marco Dinelli4, Franco Radaelli5, Alberto Malesci1 1 Gastroenterology Digestive Endoscopy Service, Humanitas Research Hospital, Rozzano, Milano, Italy; 2Gastroenterology, Nuovo Regina Margherita Hospital, Roma, Italy; 3Gastroenterology and Digestive Endoscopy, Borgomanero Hospital, Novara, Italy; 4Digestive Endoscopy, San Gerardo Hospital, Monza, Italy; 5Gastroenterology and Digestive Endoscopy, Valducce Hospital, Como, Italy Background & Aims: With regard to the efficacy of cold-polypectomy for subcentimetric polyps, no study has actually assessed the post-polypectomy completeness of the removal of polyp tissue (i.e. residual disease). On the other hand, the efficacy of an alternative method to remove diminutive polyps (i.e.!5 mm), i.e. with biopsy forceps, has been shown to be suboptimal. The purpose of the study was to evaluate the efficacy and safety of cold-polypectomy performed using a new device purposely developed for the removal of subcentimetric colorectal polyps (with a braided snare wire that is 33% thinner than traditional braided wires). Methods: Consecutive patients presenting at colonoscopy in 3 centers with at least one !10 mm polyp were included in the study, irrespectively of the presence of O10 mm lesions. Clinical success was defined as absence of polyp tissue, either hyperplastic or adenomatous, on the area of cold-polypectomy of subcentimetric polyps. Such assessment was performed on two biopsies performed on the polypectomy scar immediately after polyp removal. Post-polypectomy bleeding has been defined as any bleeding requiring immediate therapeutic endoscopic procedure or delayed treatment within 30 days from the index procedure. Results: Of 172 polyps (120 patients; 60.0% men; mean age, 64 years), 52 (30%) and 120 (70%) were !5 mm and 6-9 mm, respectively, and 144 (84%) were adenomatous. Post-cold-polypectomy biopsies revealed that only 6/172 (3.4%) subcentimetric polyps (4 adenomatous and 2 hyperplastic) were incompletely removed, corresponding to a complete resection rate of 96.6% (95% CI: 93%-98%), without difference between !5 mm and 6-9 mm categories. Two cases (1.1%) of early post-polypectomy bleeding occurred and were successfully treated with clip application. Conclusions: Cold-snare polypectomy with the new device appears to be highly effective and safe for the removal of subcentimetric polyps.
Tu1447 Endoscopic Over-Estimation of Polyp Size and Factors Influencing Degree of Bias Bradley W. Anderson*1, Thomas C. Smyrk2, Seth R. Sweetser1, Douglas W. Mahoney3, Kari S. Anderson3, Mary E. Devens1, John B. Kisiel1, David a. Ahlquist1 1 Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN; 2 Anatomic Pathology, Mayo Clinic, Rochester, MN; 3Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN Background: Polyp size strongly leverages colorectal cancer (CRC) surveillance recommendations, yet this parameter is based on subjective endoscopic estimates. Such estimates are of paramount importance, as both adenomas or sessile serrated polyps (SSPs) R1 cm are considered "advanced" and are assigned more frequent surveillance than are smaller lesions. Several prior reports suggest that endoscopists tend to over-estimate colorectal polyp size, but these studies have been relatively small with limited assessment of co-variates. Aims: Based on current practice outcomes, we sought to (1) compare assessments of polyp size between endoscopic estimation and pathology measurement and 2) evaluate factors that influence endoscopic estimation bias. Methods: Colonoscopy and pathology reports were reviewed from electronic medical records at Mayo Clinic in Rochester MN. Data were limited to the year 2012 to reflect current state of practice. Only those polyps resected in toto with both endoscopic estimation and pathology measurement recorded were included for analyses. Pathology-based measurements were considered as the criterion standard for comparison given their ex vivo ruler-based appraisal. Results: From 6067 colorectal polyps resected during the study period, 1528 met above inclusion criteria. Distribution of polyp size estimated by endoscopy revealed modal clustering, particularly around 1 cm (Fig.1a), in contrast to the smooth distribution continuum by pathology measurement (Fig.1b). Of the 222 polyps estimated as R1 cm on endoscopy, 46% were over-called (! 1 cm on pathology); while of the 1306 polyps estimated as !1cm, 3.9% were under-called (R1cm on pathology). Among the 99 polyps called 1 cm on endoscopy, 72% were !1cm on pathology, 8.1% equal to 1cm, and 20% O1 cm. The extent of endoscopic overestimation increased in proportion to polyp size. By histology, 39% of adenomas, 59% of SSPs, and 73% of hyperplastic polyps (HPs) were over-called, pZ0.008. By
Volume 79, No. 5S : 2014 GASTROINTESTINAL ENDOSCOPY AB435