- Email: [email protected]
693 Cold Piecemeal Endoscopic Mucosal Resection (EMR) for Large Sessile Serrated Colonic Polyps
Abstracts
without near-focus in the optical detection of residual neoplasia after EMR in realtime. Methods: This multicenter prospective study started in January 2016 and is ongoing. Consecutive patients undergoing follow-up colonoscopy after a previous EMR of a 20mm colorectal neoplasia were eligible for inclusion. Endoscopists predicted the presence of recurrence and their level of confidence (high or low) based on visual assessment of the previous EMR site subsequently with the following four modalities 1) high-definition white light colonoscopy without and 2) with near-focus, and 3) NBI without and 4) with near-focus. Each EMR-site was biopsied as a reference standard, and histology was assessed by a pathologist blinded to colonoscopy findings. Subsequently, all images were presented in a random order > 3 months after the index procedure to five experienced EMR physicians to check interobserver agreement for all modalities. Negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity and diagnostic accuracy including 95% confidence intervals were calculated for all diagnostic modalities for the real-time and offline image assessment. Results: Perprotocol107 patients (males: nZ58 [59%], median age: 67 [range: 45-90] years) with 111 scar sites were included, with a median follow-up of 10 (range: 3-70) months. The prevalence of residual neoplasia was 33%. Diagnostic values for all EMR-scar sites and assessed with high confidence are summarized separately for the real-time and offline assessment in table 1 and 2. The interobserver agreement for NBI near-focus was substantial (kappa: 0.81 95%-CI: 0.68-0.94) among five experienced EMR endoscopists (Table 2). Conclusion: These preliminary results suggest a very high NPV and good diagnostic accuracy for all four imaging modalities, with especially a high NPV and substantial interobserver agreement with NBI with near-focus for the optical diagnosis of residual neoplasia when assessed with high confidence in both the real-time and offline evaluation. These advanced imaging modalities may improve real-time decision making in follow-up after colorectal EMR, particularly the avoidance of biopsy.
Diagnostic value of optical detection of residual neoplasia during EMR follow-up All EMR-sites, n[111 NPV (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) High confidence diagnosis, (%) NPV, (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%)
White light
White light with near-focus
95 82 92 91 91
[88-99] [68-93] [78-98] [81-96] [84-95] 81% 96 [82-100] 93 [77-99] 96 [82-100] 93 [77-99] 96 [90-99]
96 83 92 92 91
[88-99] [68-93] [78-98] [81-96] [84-96] 83% 98 [91-100] 90 [74-98] 97 [82-100] 95 [87-99] 96 [89-99]
NBI
NBI with near-focus
[88-99] [68-93] [78-98] [81-96] [84-95] 82% 98 [91-100] 90 [73-98] 90 [73-98] 95 [87-99] 96 [89-99]
97 [90-100] 83 [69-93 ] 95 [82-99] 91 [81-96] 92 [85-96] 91% 100 [94-100] 84 [68-94] 100 [89-100] 91 [82-97] 94 [87-97]
96 82 92 91 91
[..-.], 95%-confidence interval; n, number of EMR-sites.
Table 2. Diagnostic value of optical detection of residual neoplasia during offline assessment All EMR-images, n[101
White light
White light with nearfocus
NBI
NBI with nearfocus
NPV, (%)
85 [76-92]
85 [75-91]
93 [85-97]
94 [86-98]
PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) Interobserver agreement, kappa High confidence diagnosis, (%) NPV, (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) Interobserver agreement, kappa
70 [56-82] 74 [60-85] 82 [72-89] 79 [71-85] 0.55 [0.410.69] 62%
72 [58-84] 74 [60-85] 83 [73-91] 80 [72-86] 0.57 [0.42-0.71]
76 [60-89] 86 [69-95] 88 [79-95] 87 [80-93] 0.72 [0.580.85] 77%
69 [53-82] 89 [73-97] 82 [72-90] 84 [76-90] 0.65 [0.51-0.79]
89 [78-96] 90 [73-98] 81 [64-93] 94 [85-99] 89 [81-95] 0.77 [0.630.91]
83 [71-92] 76 [59-88] 76 [59-88] 83 [71-92] 80 [71-88] 0.59 [0.43-0.76]
96 [88-100] 70 [54-84] 92 [75-99] 92 [82-97] 85 [76-91] 0.68 [0.530.83]
96 [86-100] 82 [64-94] 94 [79-99] 80 [67-89] 92 [ 84-97] 0.81 [0.68-0.94]
68%
80%
[..-..], 95%-confidence interval; n, number of EMR-images
691 Learning Curve Analysis for Colorectal Endoscopic Submucosal Dissection Tomohiko Moriyama*, Motohiro Esaki, Toshifumi Morishita, Yuji Maehata, Takehiro Torisu, Junji Umeno, Atsushi Hirano, Yasuharu Okamoto, Takanari Kitazono Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka-shi, Fukuoka-ken, Japan Background & Aims: Endoscopic submucosal dissection (ESD) for colorectal neoplasm has been shown to be effective. However, colorectal ESD is more technically difficult than colorectal endoscopic mucosal resection (EMR). The primary aim of this study was to determine the number of colorectal ESD procedures that
AB102 GASTROINTESTINAL ENDOSCOPY Volume 85, No. 5S : 2017
should be performed to acquire safe and accurate technique. Methods: We have established a multicenter database of gastrointestinal ESD, Kyushu University multicenter ESD database (KYU-MED). All cases undergoing gastrointestinal ESD in 19 participating hospitals were registered to KYU-MED between September 2006 and September 2014. In this database, a total of 560 colorectal ESD procedures performed by 34 endoscopists were registered. Each endosopist had experienced 1 to 112 colorectal ESD procedures. The cases in each endoscopist were divided consecutively into 4 learning period, period 1 (1-20 cases), period 2 (21-40 cases), period 3 (41-60 cases) and period 4 (over 61 cases). To analyze the learning curve, en bloc resection with tumor-free margin (R0 resection) rate, tumor size, procedural time and complication rate were compared among 4 groups. Results: The overall rates of R0 resection and complication were 84.0% (461/560) and 8.0% (45/560), respectively. The R0 resection rate was 77.2% (196/254) in period 1, 78.6% (99/126) in period 2, 91.2% (83/91) in period 3 and 93.3% (83/89) in period 4, respectively (p<0.01). The complication rate was 10.6% (27/254) in period 1, 11.9% (15/126) in period 2, 2.2% (2/91) in period 3 and 1.1% (1/89) in period 4, respectively (p<0.01). Three cases in period 1 underwent surgical operation due to perforation during procedure. Although tumor size was larger in period 3 and 4 compared to period 1 and 2, procedural time was not different among 4 groups. Conclusions: According to the results of this large multicenter study, approximately 40 cases of colorectal ESD should be needed to acquire safe and accurate technique.
692 Endoscopic Resection of Large Laterally Spreading Rectal Adenomas: EMR Versus Esd Hubert H. Nietsch*1,2 1 Div. of Gastroenterology, St. Elisabeth Medical Center, Halle, Germany; 2 Div. of Gastroenterology, Albany Medical College, Albany, NY Aims: Since the advent of screening colonoscopy many more asymptomatic large rectal polyps >5cm in diameter are detected. With the introduction of EMR (endoscopic mucosal resection) and ESD (endoscopic submucosal dissection) we have now endoscopic means to resect those lesions effectively. It is however still unclear whether EMR or ESD is superior in terms of complete resection and safety. Methods: We compare the outcome (perforation, bleeding, complete resection, recurrence rate) in two cohorts of patients with laterally spreading rectal adenomas >5cm who were either treated by EMR or ESD in our center. Results: 62 large laterally spreading rectal adenomas in consecutive patients’ (age 45-84 years) were completely resected endoscopically. ESD en-bloc resection was performed in 23 patients. All other lesions were excised by piecemeal EMR. Prior to resection a careful examination under white light and NBI was performed using the Paris classification. In comparison ESD took about three times as long as EMR (average procedure time 98 min vs 37 min) with comparable intra- and postoperative bleeding rates (5% in each group). No perforations were encountered. All en-bloc ESD specimens were R0 on histology. In one patient deep submucosal invasion of the submucosa (>1000mm) was present. The patient underwent surgical resection 6 weeks after the endoscopy without evidence of remaining tumor or lymph node invasion. The most striking difference in the two groups was seen regarding recurrence of adenomas during 6 months follow-up: 0% in the ESD cohort and 12% in the piecemeal EMR group. All recurrent adenomas after EMR could however be easily resected by snare polypectomy without any further recurrence over the next 12 months. The calculated average equipment cost for ESD (hook knife, dual knife, injectate, transparent cap) was significantly higher compared to EMR (687$ vs. 39$). Conclusion: EMR and ESD are equally effective in resecting large laterally spreading lesions of the rectum despite the higher rate of post-EMR adenoma recurrence which did however not impact the patients overall cure rate after one year. ESD is significantly more time consuming and costly.
693 Cold Piecemeal Endoscopic Mucosal Resection (EMR) for Large Sessile Serrated Colonic Polyps Nicholas J. Tutticci*1,2, David G. Hewett1,2 1 Queen Elizabeth II Jubilee Hospital, Brisbane, Queensland, Australia; 2 School of Medicine, University of Queensland, Brisbane, Queensland, Australia Background and Aim: Sessile serrated polyps (SSPs) are important colorectal cancer precursors however the optimal technique for the removal of large lesions remains unknown. Conventional polypectomy has limited efficacy and conventional EMR has a risk of delayed bleeding and perforation. Cold snare resection overcomes these safety concerns, although in practice, piecemeal resection is required for large lesions. In this study, we describe and evaluate a modified cold piecemeal EMR technique for large SSPs. Patients and Methods: Consecutive patients of 2 endoscopists at a single center with one or more 10mm SSPs were included. Patients on anticoagulant/antiplatelet therapy other than aspirin were excluded . Our modified EMR technique comprised: 1) submucosal injection of succinylated gelatin with dilute methylene blue, 2) piecemeal cold snare resection of all visible polyp with a
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Abstracts
wide margin (3-5mm) of normal tissue, 3) retrieval of specimen fragments by suction, 4) multiple biopsies from the margins of the resection defect to assess for residual serrated neoplasia (Figures 1 and 2). Complications were assessed at 30 day follow-up telephone call. All patients were scheduled for surveillance colonoscopy within 12 months to assess the resection site. Results: Cold piecemeal EMR was performed on 162 lesions at 104 procedures in 98 patients (70% female). Most lesions were proximal (97.5%); 61 lesions were >20mm in size and 13 lesions 30mm. SSP with cytologic dysplasia was identified in 2 (1.2%) . Two patients (1.2% of lesions) returned a single margin biopsy containing serrated tissue. Surveillance has been performed in 123 (79%) of 155 eligible lesions at a median interval of 154 days. A sole case of residual serrated neoplasia was detected at surveillance colonoscopy and occurred in one of the patients with a positive margin biopsy. The 1mm of residual serrated polyp was readily resected with a cold snare, second surveillance is awaited. Intraprocedural bleeding >60 seconds occurred in a single lesion (12mm, ascending colon SSP) with pulsatile bleeding in the center of the defect prior to margin biopsy. Hemostasis was achieved with 2 clips (Instinct, Cook) clips without rebleeding. Minor post-procedural bleeding and abdominal pain occurred in 1 patient managed symptomatically without hospital admission and which settled within 48 hours. One patient developed abdominal pain requiring hospital admission within 24 hours; this patient had a history of severe recurrent abdominal pain as the indication for colonoscopy. The patient was discharged well within 24 hours after normal clinical examination, laboratory tests and CT scan. Conclusion: Cold piecemeal EMR is a safe and effective method for removal of large sessile serrated polyps. Further evaluation of the role and constituents of the injectate is required, prior to randomized trials of the technique.
737 A Comparison of Standard Endoscopic Submucosal Dissection Technique to the New Single Tunneling Technique in Giant Laterally Spreading Tumors Fatih Aslan*1, Zehra Akpinar1, Derya A. Yurtlu2, Melek Kucuk1, Nese Ekinci3, Emrah Alper1, Belkis Unsal1 1 Gastroenterology, Izmir Ataturk Research And Training Hospital, Izmir, Turkey; 2Anestesiology and Reanimation, Izmir Ataturk Research And Training Hospital, Izmir, Turkey; 3Pathology, Izmir Ataturk Research And Training Hospital, Izmir, Turkey Background/Aim: Endoscopic submucosal dissection(ESD) has been widely accepted as an effective and minimally invasive treatment for patients with premalignant and malignant colorectal lesions. Due to the anatomic features of the colon and larger lesion sizes it may sometimes be difficult to perform colorectal ESD successfully. Here we present the results of traditional standard ESD and the new single tunneling technique in a comparative study for treatment of large laterally spreading tumors(LST) 5 cm which is the first to be presented. Method: Between April 2012-October 2016, a total of 795 colorectal lesions were referred to our unite for the purpose of removal with advanced endoscopic techniques. Colorectal ESD was performed to 354 lesions. Data was recorded prospectively before and after the procedure. Lesions measuring less than 5 cm and cases whose colonoscopic follow up were missing were excluded from the study. The rest 97 cases with lesions 5 cm in size were enrolled. The procedures were grouped as standard and tunneling ESD, and results were compared between these groups. Results: Colorectal ESD procedures were performed in 97 patients, the demographic data and results of which are shown in the table. The overall en-bloc and complete resection rates were 96.9%. There was no statistical difference between the groups regarding age, length of procedure, size of the lesions, complete resection rates and endoscopic appearance of the lesions (p>0.05). However, en-bloc resection rates and dissection speed were higher in the tunneling ESD group (p<0,05). Complications were observed less frequently in the tunneling ESD group. A total of 4 perforations developed in the whole study group, all of which were treated endoscopically without the need for surgery. In all patients with deep submucosal (sm2) invasion surgical treatment was performed, however neoplasia was observed in none of them. Conclusion: The colon has a narrow lumen and angles. Lesions may sometimes be located in between haustral structures. In addition,scopes have limited maneuver capacity due to the anatomical features. Because of these reasons it may be difficult to perform an effective and safe colorectal ESD. Single Tunneling technique may provide an effective dissection without the need for excessive air insufflation in the colon. This technique also provides an easier and appropriate approach to the submucosal area both by the mechanical effect of the scope and by the lesser loss of submucosal fluid which also help in easier dissection. Main vascular structures instead of branches can be easily coagulated. This results in less bleeding and effective bleeding control that helps in obtaining a clear view of the submucosal area. We think that due to all these advantages effects single tunneling technique especially in large LSTs can be the effective and safe ESD method among the colorectal ESD procedures.
Demographic data and colorectal endoscopic submucosal dissection results of standard and tunneling ESD method in lesions >5 cm (n[97) Figure 1. 12mm SSP Gender, male/female, n Age, years, mean (SD) (median; range) Lesion size, mm, mean (SD) (median; range) Sample size, mm, mean (SD) (median; range) Duration of procedure, min, mean (SD) (median; range) Dissection speed, mm2/min, mean (SD) (median; range) En-bloc resection rate, n (%) Complete resection, n (%) -R0 Resection -R1 Resection -Rx Resection Paris classification, n (%) -1s -1s+2a -2a -2a+2c Adverse events, n (%) -Delayed bleeding -Perforation
Standard ESD Group n[31
Tunneling ESD Group n[66
17/14 64.45(12.1) (64; 29-88) 61.58 (14.14) (56; 50-104) 68.77 (14.49) (67; 50-123) 121.26 (66.53) (102; 46-321) 28.26 (15.56) (24.15; 8.72-65.33) 28 (90.3)
44/22 65.62(10.2) (67.5; 35-85) 71.47 (29.77) (61; 50-176) 84.67 (32.85) (74; 51-198) 121.79 (82.49) (98; 47-540) 38.38 (15.78) (34.69; 17.03-82.75) 66 (100)
29 (93.5) 1 (3.2) 1 (3.2)
65 (98.5) 1 (1.5) 0 (0)
1 (3.2) 20 (64.5) 8 (25.8) 2 (6.5)
0 (0) 43 (65.2) 23 (34.8) 0 (0)
0 2
2 2
p 0.261 0.564 0.127 0.007 0.784 0.001 0.037 0.289
0.074
0.463
Figure 2. Defect after cold piecemeal EMR
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Volume 85, No. 5S : 2017 GASTROINTESTINAL ENDOSCOPY AB103
without near-focus in the optical detection of residual neoplasia after EMR in realtime. Methods: This multicenter prospective study started in January 2016 and is ongoing. Consecutive patients undergoing follow-up colonoscopy after a previous EMR of a 20mm colorectal neoplasia were eligible for inclusion. Endoscopists predicted the presence of recurrence and their level of confidence (high or low) based on visual assessment of the previous EMR site subsequently with the following four modalities 1) high-definition white light colonoscopy without and 2) with near-focus, and 3) NBI without and 4) with near-focus. Each EMR-site was biopsied as a reference standard, and histology was assessed by a pathologist blinded to colonoscopy findings. Subsequently, all images were presented in a random order > 3 months after the index procedure to five experienced EMR physicians to check interobserver agreement for all modalities. Negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity and diagnostic accuracy including 95% confidence intervals were calculated for all diagnostic modalities for the real-time and offline image assessment. Results: Perprotocol107 patients (males: nZ58 [59%], median age: 67 [range: 45-90] years) with 111 scar sites were included, with a median follow-up of 10 (range: 3-70) months. The prevalence of residual neoplasia was 33%. Diagnostic values for all EMR-scar sites and assessed with high confidence are summarized separately for the real-time and offline assessment in table 1 and 2. The interobserver agreement for NBI near-focus was substantial (kappa: 0.81 95%-CI: 0.68-0.94) among five experienced EMR endoscopists (Table 2). Conclusion: These preliminary results suggest a very high NPV and good diagnostic accuracy for all four imaging modalities, with especially a high NPV and substantial interobserver agreement with NBI with near-focus for the optical diagnosis of residual neoplasia when assessed with high confidence in both the real-time and offline evaluation. These advanced imaging modalities may improve real-time decision making in follow-up after colorectal EMR, particularly the avoidance of biopsy.
Diagnostic value of optical detection of residual neoplasia during EMR follow-up All EMR-sites, n[111 NPV (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) High confidence diagnosis, (%) NPV, (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%)
White light
White light with near-focus
95 82 92 91 91
[88-99] [68-93] [78-98] [81-96] [84-95] 81% 96 [82-100] 93 [77-99] 96 [82-100] 93 [77-99] 96 [90-99]
96 83 92 92 91
[88-99] [68-93] [78-98] [81-96] [84-96] 83% 98 [91-100] 90 [74-98] 97 [82-100] 95 [87-99] 96 [89-99]
NBI
NBI with near-focus
[88-99] [68-93] [78-98] [81-96] [84-95] 82% 98 [91-100] 90 [73-98] 90 [73-98] 95 [87-99] 96 [89-99]
97 [90-100] 83 [69-93 ] 95 [82-99] 91 [81-96] 92 [85-96] 91% 100 [94-100] 84 [68-94] 100 [89-100] 91 [82-97] 94 [87-97]
96 82 92 91 91
[..-.], 95%-confidence interval; n, number of EMR-sites.
Table 2. Diagnostic value of optical detection of residual neoplasia during offline assessment All EMR-images, n[101
White light
White light with nearfocus
NBI
NBI with nearfocus
NPV, (%)
85 [76-92]
85 [75-91]
93 [85-97]
94 [86-98]
PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) Interobserver agreement, kappa High confidence diagnosis, (%) NPV, (%) PPV, (%) Sensitivity, (%) Specificity, (%) Accuracy, (%) Interobserver agreement, kappa
70 [56-82] 74 [60-85] 82 [72-89] 79 [71-85] 0.55 [0.410.69] 62%
72 [58-84] 74 [60-85] 83 [73-91] 80 [72-86] 0.57 [0.42-0.71]
76 [60-89] 86 [69-95] 88 [79-95] 87 [80-93] 0.72 [0.580.85] 77%
69 [53-82] 89 [73-97] 82 [72-90] 84 [76-90] 0.65 [0.51-0.79]
89 [78-96] 90 [73-98] 81 [64-93] 94 [85-99] 89 [81-95] 0.77 [0.630.91]
83 [71-92] 76 [59-88] 76 [59-88] 83 [71-92] 80 [71-88] 0.59 [0.43-0.76]
96 [88-100] 70 [54-84] 92 [75-99] 92 [82-97] 85 [76-91] 0.68 [0.530.83]
96 [86-100] 82 [64-94] 94 [79-99] 80 [67-89] 92 [ 84-97] 0.81 [0.68-0.94]
68%
80%
[..-..], 95%-confidence interval; n, number of EMR-images
691 Learning Curve Analysis for Colorectal Endoscopic Submucosal Dissection Tomohiko Moriyama*, Motohiro Esaki, Toshifumi Morishita, Yuji Maehata, Takehiro Torisu, Junji Umeno, Atsushi Hirano, Yasuharu Okamoto, Takanari Kitazono Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka-shi, Fukuoka-ken, Japan Background & Aims: Endoscopic submucosal dissection (ESD) for colorectal neoplasm has been shown to be effective. However, colorectal ESD is more technically difficult than colorectal endoscopic mucosal resection (EMR). The primary aim of this study was to determine the number of colorectal ESD procedures that
AB102 GASTROINTESTINAL ENDOSCOPY Volume 85, No. 5S : 2017
should be performed to acquire safe and accurate technique. Methods: We have established a multicenter database of gastrointestinal ESD, Kyushu University multicenter ESD database (KYU-MED). All cases undergoing gastrointestinal ESD in 19 participating hospitals were registered to KYU-MED between September 2006 and September 2014. In this database, a total of 560 colorectal ESD procedures performed by 34 endoscopists were registered. Each endosopist had experienced 1 to 112 colorectal ESD procedures. The cases in each endoscopist were divided consecutively into 4 learning period, period 1 (1-20 cases), period 2 (21-40 cases), period 3 (41-60 cases) and period 4 (over 61 cases). To analyze the learning curve, en bloc resection with tumor-free margin (R0 resection) rate, tumor size, procedural time and complication rate were compared among 4 groups. Results: The overall rates of R0 resection and complication were 84.0% (461/560) and 8.0% (45/560), respectively. The R0 resection rate was 77.2% (196/254) in period 1, 78.6% (99/126) in period 2, 91.2% (83/91) in period 3 and 93.3% (83/89) in period 4, respectively (p<0.01). The complication rate was 10.6% (27/254) in period 1, 11.9% (15/126) in period 2, 2.2% (2/91) in period 3 and 1.1% (1/89) in period 4, respectively (p<0.01). Three cases in period 1 underwent surgical operation due to perforation during procedure. Although tumor size was larger in period 3 and 4 compared to period 1 and 2, procedural time was not different among 4 groups. Conclusions: According to the results of this large multicenter study, approximately 40 cases of colorectal ESD should be needed to acquire safe and accurate technique.
692 Endoscopic Resection of Large Laterally Spreading Rectal Adenomas: EMR Versus Esd Hubert H. Nietsch*1,2 1 Div. of Gastroenterology, St. Elisabeth Medical Center, Halle, Germany; 2 Div. of Gastroenterology, Albany Medical College, Albany, NY Aims: Since the advent of screening colonoscopy many more asymptomatic large rectal polyps >5cm in diameter are detected. With the introduction of EMR (endoscopic mucosal resection) and ESD (endoscopic submucosal dissection) we have now endoscopic means to resect those lesions effectively. It is however still unclear whether EMR or ESD is superior in terms of complete resection and safety. Methods: We compare the outcome (perforation, bleeding, complete resection, recurrence rate) in two cohorts of patients with laterally spreading rectal adenomas >5cm who were either treated by EMR or ESD in our center. Results: 62 large laterally spreading rectal adenomas in consecutive patients’ (age 45-84 years) were completely resected endoscopically. ESD en-bloc resection was performed in 23 patients. All other lesions were excised by piecemeal EMR. Prior to resection a careful examination under white light and NBI was performed using the Paris classification. In comparison ESD took about three times as long as EMR (average procedure time 98 min vs 37 min) with comparable intra- and postoperative bleeding rates (5% in each group). No perforations were encountered. All en-bloc ESD specimens were R0 on histology. In one patient deep submucosal invasion of the submucosa (>1000mm) was present. The patient underwent surgical resection 6 weeks after the endoscopy without evidence of remaining tumor or lymph node invasion. The most striking difference in the two groups was seen regarding recurrence of adenomas during 6 months follow-up: 0% in the ESD cohort and 12% in the piecemeal EMR group. All recurrent adenomas after EMR could however be easily resected by snare polypectomy without any further recurrence over the next 12 months. The calculated average equipment cost for ESD (hook knife, dual knife, injectate, transparent cap) was significantly higher compared to EMR (687$ vs. 39$). Conclusion: EMR and ESD are equally effective in resecting large laterally spreading lesions of the rectum despite the higher rate of post-EMR adenoma recurrence which did however not impact the patients overall cure rate after one year. ESD is significantly more time consuming and costly.
693 Cold Piecemeal Endoscopic Mucosal Resection (EMR) for Large Sessile Serrated Colonic Polyps Nicholas J. Tutticci*1,2, David G. Hewett1,2 1 Queen Elizabeth II Jubilee Hospital, Brisbane, Queensland, Australia; 2 School of Medicine, University of Queensland, Brisbane, Queensland, Australia Background and Aim: Sessile serrated polyps (SSPs) are important colorectal cancer precursors however the optimal technique for the removal of large lesions remains unknown. Conventional polypectomy has limited efficacy and conventional EMR has a risk of delayed bleeding and perforation. Cold snare resection overcomes these safety concerns, although in practice, piecemeal resection is required for large lesions. In this study, we describe and evaluate a modified cold piecemeal EMR technique for large SSPs. Patients and Methods: Consecutive patients of 2 endoscopists at a single center with one or more 10mm SSPs were included. Patients on anticoagulant/antiplatelet therapy other than aspirin were excluded . Our modified EMR technique comprised: 1) submucosal injection of succinylated gelatin with dilute methylene blue, 2) piecemeal cold snare resection of all visible polyp with a
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Abstracts
wide margin (3-5mm) of normal tissue, 3) retrieval of specimen fragments by suction, 4) multiple biopsies from the margins of the resection defect to assess for residual serrated neoplasia (Figures 1 and 2). Complications were assessed at 30 day follow-up telephone call. All patients were scheduled for surveillance colonoscopy within 12 months to assess the resection site. Results: Cold piecemeal EMR was performed on 162 lesions at 104 procedures in 98 patients (70% female). Most lesions were proximal (97.5%); 61 lesions were >20mm in size and 13 lesions 30mm. SSP with cytologic dysplasia was identified in 2 (1.2%) . Two patients (1.2% of lesions) returned a single margin biopsy containing serrated tissue. Surveillance has been performed in 123 (79%) of 155 eligible lesions at a median interval of 154 days. A sole case of residual serrated neoplasia was detected at surveillance colonoscopy and occurred in one of the patients with a positive margin biopsy. The 1mm of residual serrated polyp was readily resected with a cold snare, second surveillance is awaited. Intraprocedural bleeding >60 seconds occurred in a single lesion (12mm, ascending colon SSP) with pulsatile bleeding in the center of the defect prior to margin biopsy. Hemostasis was achieved with 2 clips (Instinct, Cook) clips without rebleeding. Minor post-procedural bleeding and abdominal pain occurred in 1 patient managed symptomatically without hospital admission and which settled within 48 hours. One patient developed abdominal pain requiring hospital admission within 24 hours; this patient had a history of severe recurrent abdominal pain as the indication for colonoscopy. The patient was discharged well within 24 hours after normal clinical examination, laboratory tests and CT scan. Conclusion: Cold piecemeal EMR is a safe and effective method for removal of large sessile serrated polyps. Further evaluation of the role and constituents of the injectate is required, prior to randomized trials of the technique.
737 A Comparison of Standard Endoscopic Submucosal Dissection Technique to the New Single Tunneling Technique in Giant Laterally Spreading Tumors Fatih Aslan*1, Zehra Akpinar1, Derya A. Yurtlu2, Melek Kucuk1, Nese Ekinci3, Emrah Alper1, Belkis Unsal1 1 Gastroenterology, Izmir Ataturk Research And Training Hospital, Izmir, Turkey; 2Anestesiology and Reanimation, Izmir Ataturk Research And Training Hospital, Izmir, Turkey; 3Pathology, Izmir Ataturk Research And Training Hospital, Izmir, Turkey Background/Aim: Endoscopic submucosal dissection(ESD) has been widely accepted as an effective and minimally invasive treatment for patients with premalignant and malignant colorectal lesions. Due to the anatomic features of the colon and larger lesion sizes it may sometimes be difficult to perform colorectal ESD successfully. Here we present the results of traditional standard ESD and the new single tunneling technique in a comparative study for treatment of large laterally spreading tumors(LST) 5 cm which is the first to be presented. Method: Between April 2012-October 2016, a total of 795 colorectal lesions were referred to our unite for the purpose of removal with advanced endoscopic techniques. Colorectal ESD was performed to 354 lesions. Data was recorded prospectively before and after the procedure. Lesions measuring less than 5 cm and cases whose colonoscopic follow up were missing were excluded from the study. The rest 97 cases with lesions 5 cm in size were enrolled. The procedures were grouped as standard and tunneling ESD, and results were compared between these groups. Results: Colorectal ESD procedures were performed in 97 patients, the demographic data and results of which are shown in the table. The overall en-bloc and complete resection rates were 96.9%. There was no statistical difference between the groups regarding age, length of procedure, size of the lesions, complete resection rates and endoscopic appearance of the lesions (p>0.05). However, en-bloc resection rates and dissection speed were higher in the tunneling ESD group (p<0,05). Complications were observed less frequently in the tunneling ESD group. A total of 4 perforations developed in the whole study group, all of which were treated endoscopically without the need for surgery. In all patients with deep submucosal (sm2) invasion surgical treatment was performed, however neoplasia was observed in none of them. Conclusion: The colon has a narrow lumen and angles. Lesions may sometimes be located in between haustral structures. In addition,scopes have limited maneuver capacity due to the anatomical features. Because of these reasons it may be difficult to perform an effective and safe colorectal ESD. Single Tunneling technique may provide an effective dissection without the need for excessive air insufflation in the colon. This technique also provides an easier and appropriate approach to the submucosal area both by the mechanical effect of the scope and by the lesser loss of submucosal fluid which also help in easier dissection. Main vascular structures instead of branches can be easily coagulated. This results in less bleeding and effective bleeding control that helps in obtaining a clear view of the submucosal area. We think that due to all these advantages effects single tunneling technique especially in large LSTs can be the effective and safe ESD method among the colorectal ESD procedures.
Demographic data and colorectal endoscopic submucosal dissection results of standard and tunneling ESD method in lesions >5 cm (n[97) Figure 1. 12mm SSP Gender, male/female, n Age, years, mean (SD) (median; range) Lesion size, mm, mean (SD) (median; range) Sample size, mm, mean (SD) (median; range) Duration of procedure, min, mean (SD) (median; range) Dissection speed, mm2/min, mean (SD) (median; range) En-bloc resection rate, n (%) Complete resection, n (%) -R0 Resection -R1 Resection -Rx Resection Paris classification, n (%) -1s -1s+2a -2a -2a+2c Adverse events, n (%) -Delayed bleeding -Perforation
Standard ESD Group n[31
Tunneling ESD Group n[66
17/14 64.45(12.1) (64; 29-88) 61.58 (14.14) (56; 50-104) 68.77 (14.49) (67; 50-123) 121.26 (66.53) (102; 46-321) 28.26 (15.56) (24.15; 8.72-65.33) 28 (90.3)
44/22 65.62(10.2) (67.5; 35-85) 71.47 (29.77) (61; 50-176) 84.67 (32.85) (74; 51-198) 121.79 (82.49) (98; 47-540) 38.38 (15.78) (34.69; 17.03-82.75) 66 (100)
29 (93.5) 1 (3.2) 1 (3.2)
65 (98.5) 1 (1.5) 0 (0)
1 (3.2) 20 (64.5) 8 (25.8) 2 (6.5)
0 (0) 43 (65.2) 23 (34.8) 0 (0)
0 2
2 2
p 0.261 0.564 0.127 0.007 0.784 0.001 0.037 0.289
0.074
0.463
Figure 2. Defect after cold piecemeal EMR
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Volume 85, No. 5S : 2017 GASTROINTESTINAL ENDOSCOPY AB103