Su1467 Endoscopic Resection of Advanced Mucosal Neoplasia at the Anorectal Junction - Endoscopic Features, Technique and Outcome

Abstracts

Su1466 Clinical Efficacy of Endoscopic Treatment for Benign Colorectal Stricture: Ballooning Dilatation Versus Stenting Chan Hyuk Park*, Jin Young Yoon, Soo Jung Park, Jae Hee Cheon, Tae IL Kim, Won Ho Kim, Sung Pil Hong Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Republic of Korea

changes, improving colonoscopy network, providing reminders to users about screening opportunities, educational strategies to improve awareness of usefulness of CRC screening and multifactor interventions aimed at increasing participation rates. Indicators in Croatian National CRC Screening Program

Invited Returned envelopes Returned with specimen Positive FOBT Colonocopy done Ph confirmed Ca Patients with polyp(s) Diverticula IBD and other findings Hemorrhoids

Number

%

Relative to:

1.056.694 210.239 184.997 12.913 8.541 472 3.329 1.238 320 2.345

84,0 19,9 16,9 7,1 62,0 5,5 39,0 14,6 3,7 27,5

eligible invited invited examined positive FOBT Colonoscopied Colonoscopied Colonoscopied Colonoscopied Colonoscopied

Results

Su1465 The Prevalence of Sessile Serrated Adenomas in a Fecal Immunochemical Test Positive Colorectal Cancer Screening Cohort Nicholas J. Tutticci*1,2, Barbara A. Leggett1,2, Mark N. Appleyard1, David G. Hewett2,1 1 Gastroenterology and Hepatology, Royal Brisbane and Womens Hospital, Brisbane, QLD, Australia; 2School of Medicine, University of Queensland, Brisbane, QLD, Australia Background: Sessile serrated adenomas (SSAs) are important, colonoscopicallysubtle precursor lesions in the serrated pathway of colorectal neoplasia. SSA prevalence rates have been described in cohorts undergoing colonoscopy for average risk screening and for clinical indications, but not in a high risk screening cohort (fecal immunochemical test positive, FIT⫹). We aimed to assess the prevalence of SSAs in participants from the Australian Bowel Cancer Screening Program, a national, population-based screening program offering fecal immunochemical testing to adults aged 50, 55 and 65, and colonoscopy for those returning a positive result. Methods: We enrolled 503 consecutive FIT⫹ screening program participants from a defined geographic catchment between 2008 and 2011. We assembled a comparison, non-screening control cohort of 1056 patients ⱖ50 years of age undergoing colonoscopy by matched colonoscopists for clinical indications from the same center. We used multiple logistic regression to analyze the predictors of SSAs in FIT⫹ screening participants, and compare the prevalence of SSAs between screening participants and controls, adjusting for age, sex, bowel preparation, colonoscopist and year of colonoscopy. Results: 164 SSAs were found in 64 (13%) of 503 FIT⫹ participants, representing 18% of all polyps; 114 (70%) of SSAs were proximal. Adenomas were found in 259 (52%) FIT⫹ screening program participants. Of these, 129 (26%) had advanced adenomas and 46 (5%) had synchronous SSAs. 10 cancers were found, none with synchronous SSAs. Among FIT⫹ screening participants, the presence of an SSA was significantly associated with the presence of synchronous adenomas (OR 2.67, p⫽0.002) and colonoscopist (OR 3.87, p⫽0.002) but not participant age, sex, year of procedure or bowel preparation. In the control group, adenomas were found in 284 (27%) patients, advanced adenomas in 80 (8%) and SSAs in 61 (6%). The crude prevalence of SSAs was 13% in FIT⫹ screening participants, compared with 6% in control patients. This difference was significant (adjusted OR 1.9, p⫽0.01) after controlling for age, sex, bowel preparation, colonoscopist and year, but not when controlling for the presence of an adenoma (adjusted OR 1.43, p⫽0.157). Conclusions: FIT⫹ screening program participants undergoing colonoscopy have a higher prevalence of SSAs than patients undergoing colonoscopy for clinical indications. However, this difference likely mirrors the higher prevalence of adenomas also seen in this screening cohort, rather than the detection of SSAs by FIT. Further, any differences need to be interpreted with caution given the variation in SSA prevalence between colonoscopists. Clinical and demographic characteristics of study patients

Age (mean) Male, n(%) Poor bowel preparation, n(%) SSA prevalence, n(%) Adenoma prevalence, n(%) Advanced adenoma prevalence, n(%)

www.giejournal.org

FITⴙ (nⴝ503)

Control (nⴝ1056)

P value (unadjusted)

58 264 (52%) 11 (2%) 64 (13%) 259 (52%) 129 (26%)

67 526 (50%) 92 (9%) 61 (6%) 284 (27%) 80 (8%)

⬍0.001 0.323 ⬍0.001 ⬍0.001 ⬍0.001 ⬍0.001

Introduction(s): Because of the low experiences, endoscopic treatment is not yet accepted as a standard option for benign colorectal strictures. In the present study, we evaluated the clinical efficacies of endoscopic treatments including balloon dilatation and self-expandable metal stent (SEMS) placement for benign colorectal strictures. Method(s): From January 1999 and July 2011, 39 patients with benign colorectal strictures were treated with either endoscopic balloon dilatation (58 sessions) or SEMSs placement (14 sessions) at Severance Hospital, Seoul, Korea. Nineteen patients (48.7%) were male and the mean age was 59.4⫾14.3 years. The causes of colorectal strictures were postoperative anastomotic strictures (71.8%), radiation (12.8%), inflammatory disease (5.1%), and ischemia (10.3%). The locations of strictures were rectum (53.8%), sigmoid colon (25.6%), descending colon (2.6%), and transverse colon (17.9%). We reviewed the patients’ medical records and clinical efficacies of endoscopic treatment, retrospectively. Result(s): The technical success and clinical success were not different between the 2 groups (balloon group vs. SEMSs group; technical success, 98.3% and 92.9%, P⫽0.353: clinical success, 89.7% and 85.7%, P⫽0.648). Reobstructions were occurred at 58.6% with balloon group and 64.3% with SEMS group (P⫽0.769), and the patency was 1171.6⫾282.3 days with balloon group and 322.4⫾122.8 days with SEMS group (Figure, P⫽0.200). The major complications were not statistically different between the 2 groups. The clinical success rate of endoscopic treatment tended to be high at postoperative anastomotic stricture (93.2%) and low at ischemia-induced stricture (75.0%, P⫽0.260). The clinical success was not statistically different between the locations of strictures, the length of strictures, the previous endoscopic treatments, and the treatment modalities. Multivariate analysis showed that radiation-induced stricture was an independent risk factor for reobstruction. Conclusion(s): Endoscopic treatment including balloon dilatation and SEMS placement was an effective and acceptable therapy for the benign colorectal stricture. Because the balloon dilatation could be performed repeatedly without serious complications, we recommend balloon dilatation as an initial option for benign colorectal stricture.

Figure. Kaplan-Meier plots for reobstruction between balloon dilatation and SEMSs placement

Su1467 Endoscopic Resection of Advanced Mucosal Neoplasia at the Anorectal Junction - Endoscopic Features, Technique and Outcome Bronte A. Holt*1, Milan S. Bassan1, Alan J. Sexton2, Stephen J. Williams1, Michael J. Bourke1 1 Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, NSW, Australia; 2Department of Anaesthetic Medicine, Westmead Hospital, Sydney, NSW, Australia Introduction: Limited data exists on the technical aspects or clinical outcomes for Endoscopic Resection (ER) of advanced mucosal neoplasia (AMN) at the anorectal junction. Issues with safety, post procedural pain, sepsis and efficacy

Volume 75, No. 4S : 2012

GASTROINTESTINAL ENDOSCOPY

AB342

Abstracts

mean that most commonly patients are managed surgically. Patients and methods: Consecutive patients with rectal laterally spreading tumours (LSTs) referred to a tertiary endoscopic resection centre were enrolled in a prospective cohort study over a 36-month period to July 2011. Standard ER was performed for lesions above the anorectal junction. A modified technique with 0.5% Ropivacaine incorporated in the submucosal injectate, resection over haemarrhoidal columns, prophylactic antibiotics and transparent cap was used for lesions involving the anorectal junction. CHI-2 or Fisher’s exact test as appropriate were used to test for association between categorical variables. Mann Whitney tests were used to assess differences in continuous outcomes between groups. Multiple logistic regression analysis was used to establish the independent predictors. Results: 103 patients with rectal LSTs were included (64% males; mean age, 66y; range, 34-87 y; mean size 47mm; range 20mm180mm). 16 lesions (15.5%) involved the anorectal junction. Safety and success of ER at the anorectal junction is similar to higher rectal resections (3 vs. 9 admissions, P⫽0.378; 93.8% vs. 89.7% success, P⫽0.349 respectively). Adenoma recurrence rate is also similar (20% vs. 27.6%, P⫽1.000). Polyp location was significantly associated with lesion histology: all anorectal junction polyps were tubulovillous adenomas and/or sessile serrated adenomas (P⫽0.004). Lesions involving the anorectal junction had significantly lower dysplasia than higher rectal lesions (P⫽0.048). Predictors of unsuccessful ER were submucosal fibrosis (P⫽0.051), poor lifting (P⫽0.021) and lesion size (OR 1.2 for every 5mm increase in LST size, P⫽0.017, 95% CI 1.04 to 1.43). Adenocarcinoma was diagnosed in 18 patients, and none involved the anorectal junction. On binary logistic regression analysis, significant independent predictors of malignancy were location above the anorectal junction (OR 5.8, 95% CI 0.8 to infinity, P⫽0.087) and Kudo pit pattern 5 (OR 23.2, 95% CI 2.1 to 1234.5, P⫽0.006). 13 patients with cancer proceeded to surgery, with no residual adenoma or carcinoma detected in 46% of surgical specimens. No patients died following ER, and 1 patient died 3 weeks post-surgery. Conclusion: Simple modification of standard ER technique allows safe and effective treatment of AMN at the anorectal junction. AMN of the anorectal junction is at low risk for invasive disease and should be treated endoscopically on an outpatient basis.

Su1468 Prevalence of Serrated Polyps in an Italian Endoscopic Unit Pietro Occhipinti*, Laura Broglia, Silvia Saettone, Giovanni Comi, Calcedonio Calcara, Elia Armellini Gastroenterology and Endoscopy Unit, SS Trinity Hospital ASL NO, Borgomanero, Italy Background and Aim: Until lately, adenomatous polyps were considered the sole precursors of sporadic colorectal cancer through the adenoma-carcinoma pathway. More recently, also serrated polyps (SP) have been identified as precursors through an alternative pathway. SP seem to cause a minority of incidence of colon cancer and majority of interval colon cancer.The aim of the study was to assess the prevalence of SP in a cohort of patients examinated in our unit. Material and Methods: we performed colonoscopy in consecutive outpatients sent for symptoms or screening or surveillance from 1 January until 30 September 2011 and reviewed pathology reports of resected lesions. Polyps were histologically classified as adenoma (tubular, tubulovillous, villous), as serrated polyps (hyperplastic/HP, sessile serrated adenoma/SSA, traditional serrated adenoma/TSA, mixed (HP-SSA or SSA-Adenoma), as adenocarcinoma and other (inflammatory, leiomioma,etc). We assessed detection prevalence, location and endoscopic characteristics of HP, SSA and TSA, age and gender of patients. All colonoscopies were performed by six endoscopists with colonscopes Olympus CF-H180AI or CF-Q165I. Bowel preparation was 2L Macrogol 3350 ⫹ ascorbic acid/sodium ascorbate the day before colonoscopy or in splitted dose (1L the evening before and 1L the morning of procedure). Results: We enrolled 1864 patients and detected 2241 polypoid and non polypoid (superficial elevated, flat, depressed) lesions in 828 patients. We found 1319/2241 (58,9%) adenomas; 10/2241 (0,4%) adenocarcinomas; 56/2241(2.5%) of others, and 856/2241(38,2%) SP: 706/2241 (31.5%) HP, 123/2241 (5.5%) SSA, 11/2241 (0.5%) TSA and 16/2241 (0.7%) mixed polyps. Detection prevalence (patients with at least one polyp per 100 colonscopies) was overall 44.4% (828/ 1864) ; 32.7% (610/1864) for adenomas, 23.8% (444/1864) for serrated lesions: 19.3% (361/1864) for HP, 0,6% (72/1864) for SSA and 0.053% (10/1864) for TSA. The median age was 63 ys for HP, 62 ys for SSA and 66 ys for TSA. Table 1 summarizes the other characteristics of SP detected. Conclusions: Our data showed that SP are detected in a sizeable percentage of patients. SSA lesions that can progress to dysplasia and malignancy, represent a considerable rate of SP. Endoscopic features (proximal position, non polypoid shape, covered by mucus or faeces) of some SSA may cause missing lesions. Serrated polyps should be regarded as important target of colonoscopies as adenomatous polyps and should be considered for educational interventions to improve their detection.

Table 1. characteristics of serrated polyps

Proximal Distal Non Polypoid ⬍ 5mm 5-10 mm ⬎ 10 mm

HP (n.706)

SSA (n. 123)

TSA (n.11)

Mixed (n.16)

142/706 (20%) 564/706 (80%) 30/706 (4,2%) 620/706 (88%) 82/706 (12%) 4/706 (0,5%)

48/123 (39%) 75/123 (61%) 51/123 (41%) 22/123 (18%) 78/123 (63%) 23/123 (19%)

4/11 (37%) 7/11 (63%) 1/11 (9%) 7/11 (67%) 4/11 (36%) –

9/16 (56%) 7/16 (44%) – 12/16 (75%) 3/16 (19%) 1/16 (6,2%)

Su1469 Does Magnifying Narrow Band Imaging or Magnifying Chromoendoscopy Help Endoscopist to Assess the Depth of Invasion in Large Sessile and Flat Polyps: Prospective Study Hui Won Jang*, Sung Pil Hong, Soo Jung Park, Jae Hee Cheon, Tae IL Kim, Won Ho Kim Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea Background/Aims: It is crucial to distinguish submucosal (SM) colorectal cancer from adenoma for an adequate therapeutic decision in large sessile and flat polyps (⬎2cm). Recently, magnifying narrow-band imaging (NBI) or magnifying chromoendoscopy (MCE) has been applied to assess the depth of invasion in colorectal neoplasias, however the clinical implications are not yet decided. The aim of the present study was to evaluate the role of NBI and MCE in assessing the depth of invasion in large sessile and flat polyps compared to morphological evaluation by experienced endoscopist. Methods: From May 2011 to September 2011, a total of 56 large sessile and flat polyps (⬎2cm) in 54 patients were enrolled. Endoscopic features of polyps (location, size, and macroscopic type) were independently evaluated by experienced endoscopist and trainees. After that, polyps were observed by magnifying NBI (type A, B, C1, C2, and C3) and MCE (type I, II, IIIS, IIIL, IV, VI, VN) by experienced endoscopist. C2 or C3 type by NBI and VI or VN type by MCE were regarded as SM cancer and C3 type by NBI and VN type by MCE as massive SM cancer. The findings were compared to histology. Results: There were 38 adenomas (22 low grade and 16 high grade dysplasia) and 18 cancers (5 superficial SM and 13 massive SM cancers). The mean age was 64.0⫾9.7 and male was 37 (66.1%). 23 polyps (41.1%) were in right colon and 33 (58.9%) were in left colon and rectum. The diagnostic accuracy of endoscopists, NBI, and MCE were 91.1%, 92.9%, and 96.4% for SM cancer and 92.9%, 87.5%, and 92.9% for massive SM cancer, respectively. When combing with NBI or MCE, the diagnostic accuracy of experienced endoscopist did not change at 92.9% and 92.9% for massive SM cancer. When combing with NBI or MCE, the diagnostic accuracy of trainee was significantly improved for massive SM cancer (58.9% to 98.2% with NBI or 92.9% with MCE; P⬍0.001). Conclusions: Conventional endoscopic evaluation of experienced endoscopist was as accurate as NBI or MCE for assessing the depth of invasion in large sessile and flat polyps.

Su1470 A Prospective Evaluation Using the Colonoscope of the Fecal Occult Blood Test-Negative Colorectal Neoplasms in a Referral Hospital Kunihiko Wakamura*, Shin-Ei Kudo, Nobunao Ikehara, Yuichi Mori, Seiko Hayashi, Kenichi Takeda, Yasuharu Maeda, Katsuro Ichimasa, Makoto Kutsukawa, Masashi Misawa, Toyoki Kudo, Noriyuki Ogata, Kenta Kodama, Yoshiki Wada, Hirotaka Nishiwaki, Takemasa Hayashi, Toshihisa Hosoya, Hideyuki Miyachi, Fuyuhiko Yamamura, Kazuo Ohtsuka Digestive Disease Center, Showa Univ. Northern Yokohama Hospital, Yokohama city, Japan Introduction: In Japan, the mortality of colorectal cancers (CRC) has increased steadily. Therefore, screening examination is essential for detection of CRC. Since the fecal occult blood testing (FOBT) is a simple, inexpensive and minimally invasive examination, we perform it widely as CRC screening examination. However, it is a controversial problem that some of CRC are negative for FOBT. The endoscopic features of the CRC with false-negative FOBT are not well known because colonoscopy is not generally performed in the FOBT-negative examinees. Aim: This prospective trial was designed to clarify the endoscopic features of CRC with false-negative FOBT. Method: From June to December, 2009, we performed 1-day immunochemical FOBT before endoscopy for 1311 examinees who consented to the purpose of colonoscopy in our hospital. We compared the FOBT-negative group with the FOBT-positive group (control group) about endoscopic findings. Result: Of a total of 1331 examinees, 887 were in the FOBT-negative groups, and 444 were in the control group. Significant differences were not admitted in the age and sex between the both

AB343 GASTROINTESTINAL ENDOSCOPY Volume 75, No. 4S : 2012

www.giejournal.org