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Su1663 Endoscopic Mucosal Resection: Prospective Evaluation of Recurrence and Complications of Large Colorectal Polyps
Abstracts
Su1664 Real-Time Endoscopic Validation of the Workgroup Serrated Polyps and Polyposis( WASP) Classification for Optical Diagnosis of Colo-Rectal Polyps Lydi M. van Driel*, Gordon Wright, Sneha John Gastroenterology, Gold Coast University Hospital, Southport, Queensland, Australia
Table 1; Accuracy of the endoscopic assessment of dysplasia within serrated lesions larger than 8mm. 95% CI – 95% confidence interval, SSP-ND – sessile serrated polyp without dysplasia as determined endoscopically, SSP-D – sessile serrated polyp with dysplasia as determined endoscopically, NPV – negative predictive value.
Su1663 Endoscopic Mucosal Resection: Prospective Evaluation of Recurrence and Complications of Large Colorectal Polyps Andres German*, Pablo Herrera Najum, Gustavo Bernardi, Gabriela Sambuelli, Pablo C. Rodríguez Gastroenterology, Instituto Modelo de Cardiología, Cordoba, Córdoba, Argentina Background: Endoscopic mucosal resection (EMR), is a major therapeutic advance in the treatment of sessile and flat colorectal polyps. The aim of the study was to evaluate the recurrence and complications of EMR in colon. Material and methods: Descriptive, prospective and observational analysis of patients treated with mucosectomy technique. From January 2011 to December 2015, patients referred for EMR of polyps lesions greater than 2 cm, with “en bloc” resection technique for lesions up to 2 cm. Lesions larger than 2 cm, were removed using the “piecemeal technique”. Argon plasma (APC) was applied for cases of suspicion of residual adenomatous tissue at the borders of the resection. The results of the complications according to the technique used and the rate of recurrence were evaluated. In all cases the endoscopic follow-up was at 4, 12 and 24 months. Results: We analyzed a total of 119 patients (71 men, 48 women), with a mean age of 63 years 12.59 and an average lesion size of 28 mm 15 mm. En bloc resection was performed in 67 patients and piecemeal in 51 patients. EMR was not attempted in one patient because the appearance of the lesion was strongly suggestive of submucosal invasive cancer. All resected specimens were retrieved for histopathological analysis, using Vienna – Paris classification, finding more than 50 % type 3. However, we observed a 20.16 % high grade dysplasia and adenocarcinoma. Complications occurred in 7 procedures (5.8%), and included three cases of post-polypectomy syndrome, a case of acute bleeding, and one delayed bleeding. Two patients experienced perforation. The mean follow-up was 15 months 9.2 months, with an overall recurrence rate of 11%, with a statistically significant (p <0.05) for the group treated with piecemeal. Conclusions: EMR was a safe technique in our series, with low rate of complications resolved successfully, and an acceptable percentage of recurrence.
Introduction: Sessile Serrated Adenomas/Polyps (SSA/Ps) are harder to characterise than traditional adenomas. The accurate differentiation of these lesions from hyperplastic polyps in particular is crucial for enabling appropriate treatment and surveillance strategies. The Workgroup serrAted polypS and Polyposis (WASP) classification has recently been developed to enable differentiation of colo-rectal polyps. The classification combines the features of the NBI International Colorectal Endoscopic (NICE) criteria with additional criteria for SSA/Ps. The WASP classification has previously been validated after training with still images followed by Gastroenterologists assessing images of further polyps. Aims and Methods: Our study aims to validate the WASP classification in the optical diagnosis of colo-rectal polyps in real-time endoscopy.2 endoscopists familiar with NBI- an experienced Gastroenterologist and a Gastroenterology Fellow- received initial training in using the WASP criteria by reviewing the classification and assessing still images. This was followed by real- time assessment of polyps over 3 months. Polyps were classified with NICE criteria and additional criteria for SSA/Ps using a step wise approach as per WASP classification. Endoscopic prediction was compared against histopathology. Statistical analyses was performed to determine diagnostic sensitivity, specificity, accuracy, positive and negative predictive values. Detailed analysis was also performed for SSA/Ps to assess the effect of bowel prep, confidence of prediction, experience of endoscopist and size of polyps. Results: 86 polyps were assessed in 27 patients. Histopathology confirmed 38 traditional adenomas( 44%), 21 hyperplastic polyps (24%) and 27 SSA/Ps(31%). 48 polyps(56%) were in the proximal colon of which 16 were SSA/Ps. 52 polyps were between 1-5 mm, 29 were 6-10 mm and only 5 were >10 mm in size. We were able to achieve NPV of 90.5% and accuracy of 88.2 for high confidence prediction of SSA/Ps and NPV of 90% for right sided SSA/Ps. Similarly, NPV of 88.6% and diagnostic accuracy of 73.6 were achieved for diminutive SSA/Ps. Detailed results for all polyps and for SSA/Ps are shown in the tables below. Conclusion: Quality of bowel prep, size and location of polyps and experience of the endoscopist may all impact on accuracy of real-time endoscopic evaluation of polyps. After a brief period of training, we were able to use the WASP classification for accurate differentiation of SSA/Ps in the proximal colon and for diminutive SSA/ Ps. However, we were not able to meet the PIVI threshold for all polyps assessed in our study. Standardised training in using the WASP criteria is expected to further improve the results and enable endoscopists of varying experience to consistently achieve high confidence prediction and diagnostic accuracy for polyp assessment during endoscopy.
Perfomance of WASP classification compared to histopathology Total polyps n[86 Sensitivity Specificity PPV NPV Accuracy
Hyperplastic polyps n[21 38.1 86.2 47.1 81.2 74.4
(17.3-58.9) (77.8-94.6) (23.3-70.8) (81.9-90.4) (65.2-83.6)
SSA/Ps n[27 70.4 76.3 57.6 84.9 74.4
Adenomas n[38
(53.1-87.6) (65.4-87.1) (40.7-74.4) (75.3-94.5) (65.2-83.6)
73.8 83.3 77.8 80.0 79.1
(59.7-87.7) (72.8-93.9) (64.2-91.4) (68.9-91.2) (70.5-87.7)
NPVZ negative predictive value, PPV- positive predictive value. Values are in percentages with 95% confidence intervals.
Histological findings HISTOLOGICAL CLASSIFICATION TUBULAR VILLOUS ADENOMA VILLOUS ADENOMA TUBULAR ADENOMA SERRATED ADENOMA SESSILE SERRATED ADENOMA HYPERPLASTIC POLYPS JUVENILE POLYPS HAMARTOMATOUS POLYPS ADENOCARCINOMA
NUMBER OF PATIENTS
PERCENTAGE
32 14 20 1 11 28 1 1 11
26.89 % 11.76 % 16.80 % 0.84 % 9.24 % 23.52 % 0.84 % 0.84 % 9.24 %
Total SSA/Ps n[27 Sensitivity Specificity PPV NPV Accuracy
Confidence of Prediction Low/High (n[16/11) 75.0/ 36.8/ 50.0/ 63.6/ 54.3/
63.6 95.0 77.8 90.5 88.2
Bowel Prep:Good /Fair (n[20/7) 70.0/ 87.1/ 77.8/ 81.8/ 80.4/
71.4 67.3 33.3 90.0 65.7
Location: Right/ Left (n[16/ 11) 81.3/ 84.4/ 72.2/ 90.0/ 83.3/
Size:Diminutive/ >5mm (n[11/16)
54.5 66.7 40.0 78.3 63.2
63.6/ 75.6/ 41.1/ 88.6/ 73.1/
75.0 77.8 75.0 77.8 72.4
Values are in percentages. Good bowel prep defined as BBPS >6
Recurrence and technique PIECEMEAL EN BLOC TOTAL
Prediction of SSA/Ps using WASP classification
RECURRENCE
NO RECURRENCE
TOTAL
10 2 12
32 60 92
42 62 104
AB386 GASTROINTESTINAL ENDOSCOPY Volume 85, No. 5S : 2017
www.giejournal.org
Su1664 Real-Time Endoscopic Validation of the Workgroup Serrated Polyps and Polyposis( WASP) Classification for Optical Diagnosis of Colo-Rectal Polyps Lydi M. van Driel*, Gordon Wright, Sneha John Gastroenterology, Gold Coast University Hospital, Southport, Queensland, Australia
Table 1; Accuracy of the endoscopic assessment of dysplasia within serrated lesions larger than 8mm. 95% CI – 95% confidence interval, SSP-ND – sessile serrated polyp without dysplasia as determined endoscopically, SSP-D – sessile serrated polyp with dysplasia as determined endoscopically, NPV – negative predictive value.
Su1663 Endoscopic Mucosal Resection: Prospective Evaluation of Recurrence and Complications of Large Colorectal Polyps Andres German*, Pablo Herrera Najum, Gustavo Bernardi, Gabriela Sambuelli, Pablo C. Rodríguez Gastroenterology, Instituto Modelo de Cardiología, Cordoba, Córdoba, Argentina Background: Endoscopic mucosal resection (EMR), is a major therapeutic advance in the treatment of sessile and flat colorectal polyps. The aim of the study was to evaluate the recurrence and complications of EMR in colon. Material and methods: Descriptive, prospective and observational analysis of patients treated with mucosectomy technique. From January 2011 to December 2015, patients referred for EMR of polyps lesions greater than 2 cm, with “en bloc” resection technique for lesions up to 2 cm. Lesions larger than 2 cm, were removed using the “piecemeal technique”. Argon plasma (APC) was applied for cases of suspicion of residual adenomatous tissue at the borders of the resection. The results of the complications according to the technique used and the rate of recurrence were evaluated. In all cases the endoscopic follow-up was at 4, 12 and 24 months. Results: We analyzed a total of 119 patients (71 men, 48 women), with a mean age of 63 years 12.59 and an average lesion size of 28 mm 15 mm. En bloc resection was performed in 67 patients and piecemeal in 51 patients. EMR was not attempted in one patient because the appearance of the lesion was strongly suggestive of submucosal invasive cancer. All resected specimens were retrieved for histopathological analysis, using Vienna – Paris classification, finding more than 50 % type 3. However, we observed a 20.16 % high grade dysplasia and adenocarcinoma. Complications occurred in 7 procedures (5.8%), and included three cases of post-polypectomy syndrome, a case of acute bleeding, and one delayed bleeding. Two patients experienced perforation. The mean follow-up was 15 months 9.2 months, with an overall recurrence rate of 11%, with a statistically significant (p <0.05) for the group treated with piecemeal. Conclusions: EMR was a safe technique in our series, with low rate of complications resolved successfully, and an acceptable percentage of recurrence.
Introduction: Sessile Serrated Adenomas/Polyps (SSA/Ps) are harder to characterise than traditional adenomas. The accurate differentiation of these lesions from hyperplastic polyps in particular is crucial for enabling appropriate treatment and surveillance strategies. The Workgroup serrAted polypS and Polyposis (WASP) classification has recently been developed to enable differentiation of colo-rectal polyps. The classification combines the features of the NBI International Colorectal Endoscopic (NICE) criteria with additional criteria for SSA/Ps. The WASP classification has previously been validated after training with still images followed by Gastroenterologists assessing images of further polyps. Aims and Methods: Our study aims to validate the WASP classification in the optical diagnosis of colo-rectal polyps in real-time endoscopy.2 endoscopists familiar with NBI- an experienced Gastroenterologist and a Gastroenterology Fellow- received initial training in using the WASP criteria by reviewing the classification and assessing still images. This was followed by real- time assessment of polyps over 3 months. Polyps were classified with NICE criteria and additional criteria for SSA/Ps using a step wise approach as per WASP classification. Endoscopic prediction was compared against histopathology. Statistical analyses was performed to determine diagnostic sensitivity, specificity, accuracy, positive and negative predictive values. Detailed analysis was also performed for SSA/Ps to assess the effect of bowel prep, confidence of prediction, experience of endoscopist and size of polyps. Results: 86 polyps were assessed in 27 patients. Histopathology confirmed 38 traditional adenomas( 44%), 21 hyperplastic polyps (24%) and 27 SSA/Ps(31%). 48 polyps(56%) were in the proximal colon of which 16 were SSA/Ps. 52 polyps were between 1-5 mm, 29 were 6-10 mm and only 5 were >10 mm in size. We were able to achieve NPV of 90.5% and accuracy of 88.2 for high confidence prediction of SSA/Ps and NPV of 90% for right sided SSA/Ps. Similarly, NPV of 88.6% and diagnostic accuracy of 73.6 were achieved for diminutive SSA/Ps. Detailed results for all polyps and for SSA/Ps are shown in the tables below. Conclusion: Quality of bowel prep, size and location of polyps and experience of the endoscopist may all impact on accuracy of real-time endoscopic evaluation of polyps. After a brief period of training, we were able to use the WASP classification for accurate differentiation of SSA/Ps in the proximal colon and for diminutive SSA/ Ps. However, we were not able to meet the PIVI threshold for all polyps assessed in our study. Standardised training in using the WASP criteria is expected to further improve the results and enable endoscopists of varying experience to consistently achieve high confidence prediction and diagnostic accuracy for polyp assessment during endoscopy.
Perfomance of WASP classification compared to histopathology Total polyps n[86 Sensitivity Specificity PPV NPV Accuracy
Hyperplastic polyps n[21 38.1 86.2 47.1 81.2 74.4
(17.3-58.9) (77.8-94.6) (23.3-70.8) (81.9-90.4) (65.2-83.6)
SSA/Ps n[27 70.4 76.3 57.6 84.9 74.4
Adenomas n[38
(53.1-87.6) (65.4-87.1) (40.7-74.4) (75.3-94.5) (65.2-83.6)
73.8 83.3 77.8 80.0 79.1
(59.7-87.7) (72.8-93.9) (64.2-91.4) (68.9-91.2) (70.5-87.7)
NPVZ negative predictive value, PPV- positive predictive value. Values are in percentages with 95% confidence intervals.
Histological findings HISTOLOGICAL CLASSIFICATION TUBULAR VILLOUS ADENOMA VILLOUS ADENOMA TUBULAR ADENOMA SERRATED ADENOMA SESSILE SERRATED ADENOMA HYPERPLASTIC POLYPS JUVENILE POLYPS HAMARTOMATOUS POLYPS ADENOCARCINOMA
NUMBER OF PATIENTS
PERCENTAGE
32 14 20 1 11 28 1 1 11
26.89 % 11.76 % 16.80 % 0.84 % 9.24 % 23.52 % 0.84 % 0.84 % 9.24 %
Total SSA/Ps n[27 Sensitivity Specificity PPV NPV Accuracy
Confidence of Prediction Low/High (n[16/11) 75.0/ 36.8/ 50.0/ 63.6/ 54.3/
63.6 95.0 77.8 90.5 88.2
Bowel Prep:Good /Fair (n[20/7) 70.0/ 87.1/ 77.8/ 81.8/ 80.4/
71.4 67.3 33.3 90.0 65.7
Location: Right/ Left (n[16/ 11) 81.3/ 84.4/ 72.2/ 90.0/ 83.3/
Size:Diminutive/ >5mm (n[11/16)
54.5 66.7 40.0 78.3 63.2
63.6/ 75.6/ 41.1/ 88.6/ 73.1/
75.0 77.8 75.0 77.8 72.4
Values are in percentages. Good bowel prep defined as BBPS >6
Recurrence and technique PIECEMEAL EN BLOC TOTAL
Prediction of SSA/Ps using WASP classification
RECURRENCE
NO RECURRENCE
TOTAL
10 2 12
32 60 92
42 62 104
AB386 GASTROINTESTINAL ENDOSCOPY Volume 85, No. 5S : 2017
www.giejournal.org