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sbevacizumab treated versus 4/59 (6.7%) in untreated. The rate of delayed perforation (>14days post stent placement) was significantly greater in bevacizumab treated patients (12.9%versus 1.7%, Fishers exact p=0.04). The rate of clinical perforation in an additional cohortof patients with unstented colorectal tumours who received bevacizumab was 5/69 (7.2%).Conclusion. Endoscopic colorectal stenting can offer durable palliation for patients withcolorectal cancer. The risk of perforation in patients with endoscopic colorectal stentswho receive bevacizumab is 2-3 times greater than with either a stent or bevacizumabtherapy alone.

Mo1026

Clinical Features of Late Bleeding Associated With Heparin Replacement AfterEndoscopic Resection for Colorectal NeoplasmsTakuya Inoue, Tsutomu Nishida, Tomofumi Akasaka, Motohiko Kato, Yoshito Hayashi,Shunsuke Yamamoto, Jumpei Kondo, Takuya Yamada, Shinichiro Shinzaki, Kenji Watabe,Hideki Iijima, Masahiko Tsujii, Tetsuo Takehara

Background: Heparin replacement is administered to patients at high-risk for thromboembol-ism during therapeutic endoscopy, but little is known about the effect of heparin replacementon the clinical course of endoscopic resection. The aim of this study was to characterizethe clinical features of late bleeding associated with heparin replacement after colorectalendoscopic resection. Methods: Consecutive inpatients that experienced colorectal endos-copic resection were enrolled at Osaka University Hospital between January 2005 andNovember 2011. Patients taking antithrombotic agents were divided into two group; theheparin replacement group (HR) and the non-HR group that included scheduled withdrawalof antithrombotic agents (WD).We studied clinical differences between two groups accordingto late bleeding after colorectal endoscopic resection. Late bleeding was defined as thatconfirming lower GI bleeding from the resection site by emergent colonoscopy or a decreasein the hemoglobin level of 2 g/dl or more even if active bleeding was not seen. A univariateanalysis was performed to evaluate factors (general condition (age, sex, body mass index,blood pressure, platelet count, and creatinine clearance), tumor property (site, size, type,and histology), and anticoagulant treatment (warfarin, antiplatelet agents, and heparinreplacement) associated with late bleeding. Multivariate analysis was carried out to identifypredictors of late bleeding among significant factors. Results: A total of 475 patients with987 lesions were identified during the study period. Total of 12 patients (3.2%) encounteredlate bleedings. Incidence of late bleeding in the HR group was 16.7% (7/42), which wassignificantly higher than those in the non-HR group [1.2% (5/433), p<0.0001]. Medianhospital stay was significantly longer in the HR group than in the non-HR group (14 vs. 4days, p<0.0001). One patient in the HR group required a blood transfusion due to massivelate bleeding. The median onset of late bleeding was on postoperative day (POD) 1 (range1-1) in the non-HR group, however on POD 4 (2-7) in the HR group. Four of seven patientsin the HR group experienced recurring episodes of late bleedings, while all patients in thenon-HR group experienced one episode. Univariate analysis revealed that use of warfarinand heparin replacement were significant factors of late bleeding. Multivariate analyses alsoyielded warfarin (p=0.0234, OR=4.894) and heparin replacement (p=0.0115, OR=7.004)as the most powerful independent predictors of late bleeding. Conclusions: Late bleedingafter colorectal endoscopic resection ismore frequent in the patients with heparin replacementtherapy than those without. Bleeding during heparin replacement could be characterizedby later onset and recurring bleeding.

Mo1027

Metachronous Colorectal Neoplasia After Adenoma Removal: A MultivariateAnalysis of Risk Factors for Non-Advanced and Advanced NeoplasiaElse-Mariette B. van Heijningen, Iris Lansdorp-Vogelaar, Ernst J. Kuipers, Marjolein vanBallegooijen, Ewout W Steyerberg

BackgroundTo ensure efficient use of resources, surveillance colonoscopy should be targeted atpatients who will benefit most from the procedure, i.e. those at highest risk for metachronousneoplasia. Internationally, surveillance guidelines are based on the advanced characteristicsand multiplicity of adenomas. Evidence for how these factors relate to each other and toother risk factors, such as older age, male gender and proximal location, however is sparse.Aim To determine the most important risk factors and their associated relative risks formetachronous (advanced) colorectal neoplasia, in a representative cohort of adenomapatients. Methods We used the Dutch nationwide histopathology registry to select newlydiagnosed adenoma patients from 1988 to 2002 from 10 hospitals throughout theNetherlands. We excluded patients with a history of CRC or CRC at index colonoscopy,hereditary colorectal cancer syndromes or IBD. Electronic medical records were reviewedup to December 1, 2008 for follow-up data. Patient characteristics (gender and age) andadenoma characteristics (number, size, location, villousness and grade of dysplasia) at indexcolonoscopy were considered as potential risk factors for metachronous colorectal neoplasiaat first follow-up. Advanced colorectal neoplasia was defined as advanced adenoma or CRC.We performed a multinomial logistic regression analysis to simultaneously assess relativerisks (odds ratios (OR (95% CI)) for non-advanced and advanced colorectal neoplasia. Themultivariate analysis was also adjusted for bowel preparation, reach of the colonoscope (bothat index colonoscopy), and surveillance interval. Results The analysis included 2,990 adenomapatients (55% male, mean age 61 (SD 10) years). At a median surveillance interval of 24months, 826 (28%) patients had any metachronous colorectal neoplasia, 145 (5%) hadadvanced adenoma(s) and 26 (0.9%) had cancer. Risk factors for metachronous non-advancedcolorectal neoplasia were male gender (OR 1.4 (1.1-1.6)), number of adenomas (OR rangingfrom 1.4 (1.1-1.8) for 2 adenomas to 2.6 (1.5-4.3) for patients with 5 or more adenomas),and proximal location (OR 1.2 (1.0-1.5)). Risk factors for metachronous advanced colorectalneoplasia were male gender (OR 1.6 (1.1-2.2)), age (OR 1.3 (1.1-1.5) per 10 years older),number of adenomas (OR ranging from 1.7 (1.1-2.5) for 2 adenomas to 3.3 (1.5-7.1) for5 or more adenomas), large size (≥10mm) adenoma (OR 2.1 (1.5-3.0)), and proximallocation (OR 1.8 (1.2-2.6), Table 1). Conclusion Next to multiplicity and size, older age,male gender and proximal location were important risk factors for metachronous advancedcolorectal neoplasia. This implies that more detailed combinations of risk factors should beconsidered for better tailored surveillance guidelines.

S-576AGA Abstracts

Table 1. Relative risks (OR (95% CI)) on metachronous non-advanced and advanced colorec-tal neoplasia (n = 2,990)

*Adjusted for bowel preparation, reach of the colonoscope (both at index colonoscopy),and surveillance interval NAA = non-advanced adenoma(s) AA/CRC = advanced adenoma(s)(adenoma with a size of ≥10 mm, villousness, or high grade dysplasia) or CRC

Mo1028

Retrospective Single-Center Trial Comparing Antegrade Spiral EnteroscopyWith Single and Double-Balloon EnteroscopyIvan F. Hung, Sze Hang Kevin Liu, Wai keung Leung

Background Spiral enteroscopy (SE) by the antegrade approach is emerging to be a safe andrapid enteroscopy technique. We performed a single center retrospective study to comparethis new technique with double-balloon (DBE) and single-balloon enteroscopy (SBE) exam-ination performed previously. Patients andMethods Between September 2004 and November2011, patients who underwent enteroscopy examination by antegrade approach wererecruited. Performance of the three different techniques including SE, DBE and SBE wascompared. The primary end point of the study was the total examination time. The secondaryend points include the time required for insertion of the enteroscope to the deepest point,the depth of insertion and complication rate. Results A total of 108 (20 SE, 55 DBE and33 SBE) examinations performed. Baseline demograpics including age (median 70 years)and sex (47% male) were well matched among subjects in the three groups. Both the mediantotal examination time and the median time required for deepest insertion was significantlyshorter for SE when compared with DBE or SBE (median total examination time: 74 minutesvs. 128 minutes vs. 93 minutes; P < 0.001) and (median time for deepest insertion: 50minutes vs. 102 minutes vs. 78 minutes; P < 0.001). The median maximum depth ofinsertion was significantly greater in the SE and DBE groups when compared with the SBEgroup (320cm vs. 320cm vs. 280cm; P < 0.001). The SE group is associated with significantlyhigher complications rate of mucosal damage when compared with the DBE and SBE groups(P < 0.001). Conclusions SE technique for small bowel examination is as effective as thetwo established technique of DBE and SBE, with significantly shorter examination time butassociated with more complication of mucosal damage.

Mo1029

Timing and Diagnostic Yield of Endoscopy Among Patients With GERDHashem El-Serag, Marilyn Hinojosa-Lindsey, Zhigang Duan, Jason Hou, Aanand D. Naik,Richard L. Street, Guoqing J. Chen, Jennifer R. Kramer

Background: Esophagogastroduodenoscopy (EGD) for patients with GERD is often advocatedto screen for Barrett's esophagus (BE) and early detection of gastroesophageal cancer. How-ever, the yield of this procedure and its relationship to timing is unclear. This informationis important to making rational recommendations about screening EGD in patients withGERD. Methods: We examined a national cohort of veteran patients with newly recordedGERD diagnosis during 2004 and 2009 in the national Department of Veteran Affairs (VA)administrative data known as Inpatient and Outpatient Medical SAS Datasets. GERD wasdefined by presence of at least 1 inpatient diagnosis or 2 outpatient diagnostic codes within18 months of each other. The earliest diagnosis date served as GERD index date. We excludedall patients with a prior diagnosis of BE or esophageal or gastric cancer. We searched forrecords of upper GI endoscopy after GERD index date and through 9/30/2011. The diagnosticyield (BE, esophageal or gastric cancer) was calculated as proportions of patients who hadan upper GI endoscopy in successive years following GERD index date. Results: A total of751,828 met the inclusion and exclusion criteria; diagnosed in 129 facilities. Approximately93.7% were men; 67.9% were white Caucasians, and their mean age was 61.6 (SD 14.0).Approximately 13.9% (n=105,050) had a recorded EGD in the VA during a median of 4.5years follow up after GERD index date. Half of those who had EGD had it in the first yearfollowing GERD index date (n=59,029, 7.85%). Of those who underwent endoscopy, theoverall yield was 11.8% for BE, 0.46% for esophageal cancer, and 0.13% for gastric cancer.The yield of BE was remarkably constant despite the duration of time from GERD indexdate to EGD, years 1, 2, 3, 4, and 5 and 9.49%, 11.20%, 10.26%, 10.15%, and 9.98%,respectively. The prevalence of esophageal cancer was 0, 1.03%, 1.08%, 1.03%, and 1.00%,and that of gastric cancer was 0, 0.54%, 0.56%, 0.41%, and 0.57% for patients who hadtheir first EGD in years 1, 2, 3, 4, and 5, respectively. Patients who had an EGD were morelikely to be female, younger than 65 yrs, and non-white, while patients with BE were 2- 3times more likely to be male, older than 65 and white. Conclusions: A small proportion of