Su1529 Residual Neoplasia At First Follow up Colonoscopy: Defining the Endoscopic Mucosal Resection Learning Curve

Abstracts

Su1528 Endoscopic Mucosal Resection of Sporadic Duodenal Polyps Is Associated With a High Risk of Complications Pieter J. Martens1, Ingrid Demedts1, Stijn Van Gool2, Hilde Willekens1, Raf Bisschops*1 1 Gastroenterology/Endoscopy, University Hospital Leuven, Leuven, Belgium; 2Gastroenterology, AZ Turnhout, Turnhout, Belgium

acquisition. Methods: The subject was a junior faculty with no prior EUS experience at a 1,000 bed corporate hospital in Asia that had instituted a new EUS program in 2010. An expert endosonographer (ASGE Member) from a teaching institution in United States visited the hospital in Asia to proctor the subject in EUS. Ten procedures were performed per day for one week using the stationbased approach. All cases were performed under propofol and included an equal case-mix of diagnostic and therapeutic procedures. The subject then documented his FNA outcomes over the next three years. Onsite cytopathology service was not available. Main outcome measures: Compare the rates of non-diagnostic FNA specimens over a 3-year period. Results: With supervision using the station-based approach, the subject was able to elicit the "stack-sign" (surrogate marker for minimal competency) at the end of the one-week training. Of a total of 415 EUS procedures performed over three years, 161 (38.8%) were FNAs; after excluding 29 patients due to lack of adequate follow-up, the remaining 132 (Male 56.1%, median age 52 yrs) formed the study cohort. EUS-FNA yielded an overall diagnostic adequacy of 73.5% (97 of 132 patients) that included pancreatic-biliary malignancy in 27.3%, metastatic cancer in 5.3%, luminal cancer in 3%, granulomatous/benign lymph nodes in 15.9%, chronic pancreatitis/benign disease in 22.0%. The overall rate of non-diagnostic specimens decreased from 34.2% to 18.2% (pZ0.03) between the first and second 18 months, respectively (figure). Limitations: The long learning curve could be attributed to the lack of onsite cytopathology support which is prevalent in a majority of centers worldwide. The study findings pertain only to tissue acquisition and did not examine competency in performing EUS. Conclusion: An intensive, one-week, hands-on EUS training program yielded a diagnostic adequacy rate of about 75% for tissue acquisition that improved with time. This data may be useful for practitioners interested in pursuing short-term hands-on training in EUS.

Background: Endoscopic mucosal resection (EMR) is an established technique for the treatment of early neoplastic lesions in the colon, esophagus and the stomach. Sporadic duodenal adenomas (SDA) are a rare finding on endoscopy. Little data is available about the safety and efficacy of EMR for SDA in larger case series. The aim of this study is to report our experience with regard to the safety and efficacy of duodenal EMR for SDA. Methods: Prospectively collected data of fifty nine patients (31 men, 28 female, mean age 61) referred for duodenal EMR to our center between 2006 and 2013, were analyzed. Only duodenal polyps were included in the study. Data regarding polyp size, location, endoscopic morphology, EMR technique, procedure time, complications, pathology result and periodical follow up were recorded. All patients underwent day after endoscopy to detect and treat delayed bleeding. Results: Seventy-one duodenal EMRs were performed in fifty nine patients using the lift and snare technique. The median polyp size was 15mm (range 7-40 mm). The success rate of complete endoscopic removal after a single EMR was 83%. Complete remission was achieved with 2 and 3 EMRs in 9 and 3 patients respectively. Complications occurred in 26% of the procedures. We encountered 10 cases of early bleeding (!4 hours after EMR) and 10 cases of delayed bleeding (O4 hours after EMR) with need of additional hemostatic measures, transfusion or radiological intervention and admission to intensive care. In one patient a small perforation could be managed conservatively with clips. No patients were referred for rescue surgery. Expect for 2 neuro-endocrine tumors, all lesions were adenomas with low grade dysplasia in 82% and high grade dysplasia in 18%. Long term histological follow up (median: 18 months, range 12-50 months) was available in 30 patients, complete histologic remission was achieved in 25 patients (83%). Five patients revealed histologic arguments of residual adenomatous tissue, all showing low grade dysplasia. No tumor or procedure related deaths were reported. Conclusion: This study is one of the largest available series confirming the efficacy of EMR for SDA. Duodenal EMR is efficient (83%) in achieving long term complete histological remission. However morbidity (26%) seems higher for duodenal EMR as compared to EMR in other location within the gastrointestinal tract and in comparison to other smaller series. Our systematic approach of day after follow-up endoscopy could contribute to the higher morbidity rate with detection of non-significant late bleeding.

Su1529 Residual Neoplasia At First Follow up Colonoscopy: Defining the Endoscopic Mucosal Resection Learning Curve Abhishek Bhurwal*, Massimo Raimondo, Michael B. Wallace, Michael Heckman, Timothy a. Woodward Mayo Clinic, Jacksonville, FL Introduction: Endoscopic Mucosal Resection (EMR) is one of the main treatment modality for the removal of flat colorectal polyps. Residual neoplasia is often seen

Fraction (%) with residual disease

EMR number

1-20

21-40

41-60

61-80

81-100

101-120

121-140

141-160

161-180

181-200

201-220

221-240

241-260

261-280

281-300

301-320

321-340

341-360

Endoscopist 1 (NZ96 lesions with follow-up

3/5 (60%)

2/5 (40%)

0/0 (0%)

1/5 (20%)

3/10 (30%)

2/6 (33%)

2/7 (29%)

2/2 (100%)

0/1 (0%)

0/1 (0%)

0/0 (0%)

3/11 (27%)

0/13 (0%)

4/12 (33%)

1/8 (13%)

0/5 (0%)

1/5 (20%)

0/0 (0%)

Endoscopist 2 (NZ128 lesions with follow-up

3/9 (33%)

0/0 (0%)

3/8 (38%)

7/14 (50%)

7/13 (54%)

2/6 (33%)

1/2 (50%)

0/4 (0%)

0/0 (0%)

1/5 (20%)

2/10 (20%)

1/11 (9%)

6/14 (43%)

2/12 (17%)

5/13 (38%)

3/7 (43%)

0/0 (0%)

N/A

Endoscopist 3 (NZ90 lesions with follow-up

3/4 (75%)

1/7 (14%)

2/14 (14%)

0/0 (0%)

1/3 (33%)

2/9 (22%)

1/11 (9%)

0/8 (0%)

1/7 (14%)

0/13 (0%)

2/7 (29%)

0/5 (0%)

0/2 (0%)

0/0 (0%)

N/A

N/A

N/A

N/A

Overall

9/18 (50%)

3/12 (25%)

5/22 (23%)

8/19 (42%)

11/26 (42%)

6/21 (29%)

4/20 (20%)

2/14 (14%)

1/8 (13%)

1/19 (5%)

4/17 (24%)

4/27 (15%)

6/29 (21%)

6/24 (25%)

6/21 (29%)

3/12 (25%)

1/5 (20%)

0/0 (0%)

Association between EMR number and residual disease at first follow-up OR: 0.75, 95% CI: 0.59 - 0.95, PZ0.019 OR: 0.88, 95% CI: 0.73 - 1.06, PZ0.18 OR: 0.62, 95% CI: 0.39 - 0.97, PZ0.038 OR: 0.80, 95% CI: 0.70 - 0.92, PZ0.002

ORZodds ratio; CIZconfidence interval. Associations between EMR number and residual disease at first follow-up were evaluated using logistic regression models. The overall model including all 3 endoscopists was adjusted for endoscopist. ORs correspond to an increase in 50 lesions. An ORO1 indicates that residual disease at first follow-up was more common as EMR experience increased, while an OR!1 indicates that residual disease at first follow-up was less common as EMR experience increased.

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Abstracts

due to the demanding skill required in performing EMR on sessile colonic polyps. Objectives: To define the learning curve of EMR of colon polyps in terms of the residual disease. Methods: EMRs on 744 patients (Mean age 68.5 years SD 11.3 , 48% females, 48% ASA 2) with 956 total lesions (mean polyp size 19.6 mm SD 17.5 Range 4-150 mm, 71% right sided) performed at Mayo Clinic Florida by 3 primary endoscopists between December, 2004 and September, 2013 were included. Endoscopist 1 performed 265 EMRs (360 lesions), endoscopist 2 performed 269 EMRs (327 lesions), and endoscopist 3 performed 210 EMRs (269 lesions). There were a total of 314 follow-up visits for these lesions. EMRs and lesions were ordered sequentially for each endoscopist and grouped into intervals of 20 lesions. Logistic regression models were utilized to evaluate the presence of a general increase or decrease in the frequency of each outcome as EMR experience increased; models were examined separately for each endoscopist as well as when combining all 3 endoscopists (in which case models were adjusted for endoscopist. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. P-values of 0.05 or lower were considered as statistically significant. Results: Overall, the frequency of residual neoplasia decreases as the EMR experience increased. There was a general decrease in the frequency residual disease which appeared to stabilize at less than 20 % after EMRs on approximately 120 lesions. Limitations: Non randomized studyConclusions: These findings demonstrate that approximately 120 EMR procedures are required by an endoscopist to achieve plateau experience in EMR proficiency.

Su1530 Learning Curve of Endoscopic Sub-Mucosal Dissection (ESD) Lessons Learnt in a Tertiary Referral Center From a Non-Endemic Region for GI Cancers Amol Bapaye*, Nachiket Dubale Dept. of Digestive Diseases & Endoscopy, Deenanath Mangeshkar Hospital & Research Center, Pune, India Introduction: Endoscopic sub-mucosal dissection (ESD) is fast replacing endoscopic mucosal resection (EMR) as a preferred treatment for mucosal & sub-mucosal lesions including early gastric cancer (EGC), flat rectal & colonic adenomas & submucosal tumors from layer 2/3. ESD & EMR are well established in regions endemic for GI cancers but their utility is limited in other regions. Aims & Methods: To evaluate the learning curve for ESD at a low volume center from a non-endemic region for GI cancers. Patients with mucosal/sub-mucosal (inner 3 layers) lesions diagnosed on endoscopy & radial EUS underwent ESD. Alternatives - EMR / EPMR / surgery were discussed preoperatively. Standard ESD technique was attempted in all. If technical difficulty or inability for enbloc resection was encountered, the procedure was converted to EMR or EPMR. If latter, subsequent fulguration of residual islands was performed using APC. Follow up endoscopy was at 1, 3, 6 months. Results: Duration: 27 months (Aug ’10 - Mar ’13), N Z 33, M: F Z 25:8, mean age: 61.2 years (19 - 83). Locations of lesions: stomach - 9, rectum - 8, colon - 10, esophagus - 2, duodenum - 4 patients. Pathology: villous adenoma (VA) - 16 (recurrent after previous attempts at EMR - 3, CA in situ - 2), adenoma - 3 (HGD / CA in situ - 2), sessile hamartomatous polyps - 2, sessile hyperplastic polyp - 1, carcinoid - 4, SMT - 7. Enbloc resection was successful in 24 / 33 patients (72.7%). In the remaining 9 patients EPMR was performed. For evaluation of results, patients were divided in 2 groups (initial 20 patients & subsequent 13 patients). Both groups were comparable for location, nature of lesion & mean size - 27.5cm2 v/s 21.5cm2 (p O 0.05). In Gr. 1, enbloc resection was successful in 13 / 20 (65%) patients v/s 11 / 13 (85%) in Gr. 2. Mean procedure time was comparable in both groups - 81min (30 150) & 82min (25 - 150), NS. Perforation occurred in 2 patients (Gr. 1) - treated by surgery - 1, endoscopic clip closure - 1; in Gr. 2, 2 patients (both SMT’s) underwent full-thickness resection (EFTR) to achieve enbloc resection and the FT or partial muscle defect thereby created was closed using endoscopic clips. Recurrence occurred in 4 / 20 (20%, Gr. 1) v/s 1 / 13 (8%, Gr. 2) - all villous adenomas post EPMR. Conclusion: VA & other mucosal / SM lesions present opportunities to perform ESD in centers with low volumes of early cancers. ESD appears to be superior for VA than EMR to prevent recurrence. In our study, enbloc resection was more successful in Gr. 2 and conversion to EPMR was more frequent in Gr. I. Complications could be endoscopically treated in Gr. II whereas surgery was required in Gr. I. Based on our study, we suggest a learning curve of minimum 20 ESD procedures in a low volume center to achieve reasonable proficiency in ESD procedures.

Medicine, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan Background: Colorectal endoscopic submucosal dissection (C-ESD) is an excellent method of treatment for colorectal neoplasms. However, it is technically demanding, so the development of a training system is essential. Aim:1) To clarify pre-training requirements for C-ESD operators. 2) To clarify how many cases of CESD are necessary for novice operators to acquire an adequate level of technical skill. Methods: In our institute, trainees begin to perform C-ESD for rectal lesions after performing approximately 30 cases of gastric ESD. 1) We analyzed the early treatment outcomes of C-ESD performed by four trainees (after October 2006). 2) We analyzed the treatment outcomes of a) C-ESD performed by two endoscopists in our institute, who had completed C-ESD training at other hospitals; b) C-ESD performed by two endoscopists, who had performed more than 30 cases of C-ESD in our institute. Results: 1) The number of gastric/esophageal ESD (G-/E-ESD) cases performed by the four trainees (a, b, g: 7 years after graduation, d: 10 years) was as follows: 32/0 (a), 36/2 (b), 36/0 (g), 87/3 (d). Their G-ESD results are shown in Table 1. By September 2013, the number of performed C-ESD cases was 172 (a), 19 (b), 61 (g), 13 (d), respectively. Of these cases, there were two incidences of local recurrence: one was cured endoscopically, but the other surgically. The treatment outcomes of C-ESD performed by the four trainees (the first 30 cases, at most) are also shown in Table 1. 2) a) Two endoscopists (ε: 11 years after graduation, z: 10 years) who had completed C-ESD training at other hospitals began performing C-ESD at our institute in April, 2013. By then, the number of performed ESD cases per endoscopist (G/E/C) was 168/6/28 (ε), 405/38/122 (z), respectively. By September 2013, endoscopist ε had performed 4 cases of C-ESD, while z had performed 9 cases at our institute. The clinical outcomes of their C-ESD are shown in Table 2.b) The results of C-ESD performed by endoscopist a and g (after 30 cases) are also shown in Table 2. Conclusions: After experiencing approximately 30 cases of G-ESD and achieving an en block R0 resection rate of over 95%, the treatment results of C-ESD performed by trainees maintained a high standard. As the trainees gain more experience, they tend to move on to more difficult lesions, so it is difficult to assess a specific trend in the learning curve of C-ESD. However, after performing 30 cases of C-ESD, the treatment outcomes were adequate, given that 6 of the 7 cases of procedure cessation resulted from either submucosal or muscular invasion. However, we would have to say supervision is inevitable at that stage. It is necessary to investigate the learning curve after 30 cases.

Su1531 Requirements for Mastering Colorectal Endoscopic Submucosal Dissection Indicated by the Learning Curve of Multiple Endoscopists Yosuke Tsuji*1, Yoshiki Sakaguchi1, Satoshi Mochizuki1, Keiko Niimi1,2, Satoshi Ono1,3, Shinya Kodashima1, Nobutake Yamamichi1, Mitsuhiro Fujishiro1,2, Kazuhiko Koike1 1 Department of Gastroenterology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan; 2Department of Endoscopy and Endoscopic Surgery, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan; 3Center for Epidemiology and Preventive

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