markers as their predictive value for significant SB inflammation is moderate at best. Capsuleretention was very rare and did not require invasive intervention.

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Laboratory Predictors of Hyperamylasemia and Hyperlipasemia After DoubleBalloon EnteroscopyMarcela Kopacova, Jan Bures, Stanislav Rejchrt, Jaroslava Vavrova, Tomas Soukup, JanToms, Jolana Bartova, Ilja Tacheci

Objective The causal mechanism of acute pancreatitis after oral double balloon enteroscopy(DBE) is still uncertain. The most probable cause seems to be a mechanical straining of theendoscope with an over-tube on the pancreas. Hyperamylasemia and hyperlipasemia afterDBE are frequent and usually asymptomatic. They do not represent the immediate riskfactor of acute pancreatitis. The aim of this prospective study was to investigate severallaboratory markers to predict patients in a higher risk of hyperamylasemia and hyperlipasemiaand/or possible DBE-associated acute pancreatitis. Methods A total 38 patients (18 men and20 women, mean age 51 years) with 44 DBEs and 30 matched healthy controls with noendoscopy entered the study. Following laboratory markers were investigated before, 4hours and 24 hours after DBE and once in controls: serum hs-CRP, prokalcitonin, total S100protein, cathepsin B, SPINK1, lactoferrin, E-selectin, alfa-1-antitrypsin, malondialdehyde,amylase and lipase. The mean time of DBE was 80 min. (range 20 - 210 min.), the meannumber of push-and-pull cycles was 14 (range 1 - 41). We have not recorded any DBE-associated acute pancreatitis in this series. Results Serum amylase and lipase rose significantlywith the maximum 4 hours after DBE, with increased abnormal values in 31/44 (70%) ofserum amylase and 29/44 (66%) of serum lipase (p < 0.001 and p < 0.001). Serum cathepsinand procalcitonin decreased significantly 4 hours after DBE compared to healthy controlsand patients' values before DBE (p = 0.018 and p = 0.031). There was a statistically significant,but clinically irrelevant, difference in malondialdehyde between males and females 4 hoursafter DBE (0.33±0.20 vs. 0.20±0.13 μmol/L; p = 0.012). No other gender-associated differencewas recorded. There was a trend for an association between number of push-and-pull cyclesin DBE and procalcitonin (r = -0.384; p = 0.011) and urine amylase (r = 0.313; p = 0.043)4 hours after DBE; between procalcitonin and alfa-1-antitrypsin (r = 0.358; p = 0.021),cathepsin (r = 0.362; p = 0.020) and hs-CRP (r = 0.358; p = 0.021); and between E-selectinand malondialdehyde (r = 0.364; p = 0.019) 4 hours after DBE. Either serum amylase orlipase 4 hours after DBE did not correlate with any markers before DBE. Conclusions Ourcurrent results support our previous hypothesis that endoscope-induced mechanical strainingduring DBE is the most important factor responsible for the increase of amylase and lipaseor even for progression to acute pancreatitis. We found no laboratory predictive markersthat would identify in advance those patients in a higher risk. This study was supported bythe research grant MH CZ NT11524-5/2010 and by the programme PRVOUK 37-08.

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Clinical Experience in Double-Balloon Enteroscopy At a U.S. Tertiary MedicalCenterDushyant Damania, Albert C. Kim, Kaartik Soota, Sonia Yoon, Donald N. Tsynman, VivekKaul, Shivangi Kothari, Ashok Shah, Asad Ullah

Objective: To characterize the major indications for DBE, measure the diagnostic detectionrates and characteristics of findings, and assess major complications in a large cohort froma US tertiary medical center. Patients/Methods: All patients undergoing DBE from January2007 to December 2011 in a single center underwent retrospective analysis. Results: 350procedures were performed on a total of 274 patients, which included 252 antegradedouble balloon enteroscopies (DBE) and 98 retrograde DBEs (rDBE). The indications forthe procedures were divided into Anemia of Unknown Cause (46.9%), Obscure GI bleed(31.5%), Suspected Mass Lesions (8.4%), and Others (13.2%), each of which constituteda sub-group for further analysis. Overall lesion detection rate was 61.3% for all procedures.In sub-group analysis, the detection rate was 60.9%, 53.7%, 63.3% and 44.7% for anemia,obscure GI bleed, mass lesion and others, respectively. Among patients with anemia whohad positive findings on DBE, vascular lesions constituted 79.0%, while mass lesions andother lesions accounted for 16.0% and 5%, respectively. In obscure GI bleeds, 77.0% werevascular lesions, 17.9% were mass lesions and 5.1% were other lesions. 178 patients (65.0%)had at least one prior packed cell transfusion. In the anemia sub-group, patients who receivedat least one blood transfusion were more likely to have a positive result on DBE, and thiswas statistically significant (OR 9.12, 95% CI: 4.4-18.9). Major complications includedone perforation (0.29%) requiring surgery and one episode of mild pancreatitis (0.29%).Conclusion: To our knowledge, this is the largest single center study in North America,evaluating diagnostic detection rates of DBE. Our study found that vascular lesions accountedfor 77% of positive findings in the obscure GI bleeding grouop, which is higher than thepreviously reported 63.0% observed in North America. Our study reconfirms previousfindings in terms of overall lesion detection and complication rates of DBE. Finally, wefound that anemic patients who had a prior transfusion were 9 times more likely to havea positive finding on DBE than those who did not. This implies that we should have a lowerthreshold for DBE in anemic patients who have required a blood transfusion.

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Clinical Usefulness of the Novel Tag-Less PillCam® Patency Capsule for theScreening of Patients With Suspected Small Bowel StricturesTamotsu Sagawa, Tomohiro Kubo, Yasuhiro Sato, Yasushi Sato, Hidetoshi Ohta, TokikoNakamura, Koshi Fujikawa, Yasuo Takahashi

BACKGROUND:Capsule endoscopy (CE) is a non-invasive diagnostic tool for the study ofthe small bowel. The main complication of CE is capsule retention, defined as a failure toexcrete the capsule for 2 weeks or more requiring directed medical, endoscopic, or surgicalintervention. Due to the risk of capsule retention, CE is contraindicated in patients withsuspected small bowel strictures. The novel tag-less PillCam® Patency Capsule (PPC) for

S-767 AGA Abstracts

preventing capsule retention which was marketed in 2012 in Japan has expanded theindication of small bowel disease for CE. OBJECTIVES:We investigated the safety and clinicalusefulness of the novel tag-less PillCam® Patency Capsule for preventing capsule retentionin patients with suspected small bowel strictures. PATIENTS AND METHODS:Sixteenpatients who suspected small bowel strictures were included (mean age: 66.2) in thisretrospective study. If patients had already excreted the intact PPC in the stool at 30 h afteringestion of PPC, patency of the small bowel was confirmed. If the confirmation at 30 hwas not successful, reconfirmation was performed by abdominal X-ray and/or computedtomography (CT) within 33 hours after the ingestion. If the intact PPC had reached tocolon, we judged "patency". Except for the above-mentioned, we judged "no patency". Ifpatency was established, then the patients underwent CE. RESULTS:Male/Female (8/8).Clinical indications before the PPC were melena or hematochezia (6), abdominal pain (3),abdominal distension (2), abdominal mass (4) constipation (1), diarrhea (1), anemia (2),no abdominal symptom (4). A history of abdominal surgery +/- (4/12). A history of abdominalirradiation +/- (5/11). Fourteen cases (87.5%) had complete PPC examination followed byCE within 2 weeks. We judged 2 cases "no patency". Each of two cases showed the symptomsof ileus. One case needed ileus tube insertion and gastrografin enema showed stricture. Inanother case, gastric tube was inserted. In both cases, the ileus improved after conservativetreatment. Fourteen patients underwent CE following the patency capsule examination. In10 cases (71.4%) of them, the significant pathologic findings were found by CE. Althoughthe confirmation of the patency by PPC was established, retention occurred in one casewith asymptomatic. The patient had prior operation history of ileum-transverse colon bypass.CONCLUSIONS:Passage is a direct proof of the patency of small bowel. The tag-less PillCam®Patency Capsule was useful to evaluate the patency of the small bowel to confirm the safercapsule endoscopy in patients with suspected small bowel strictures. However, the PPCitself may show the symptoms of ileus. The cases with abdominal surgical history could bea risk for capsule retention even though PillCam® Patency Capsule confirmed the patency.

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Volumetric Analysis of Colonic Distention At Screening CT Colonography:Objective Comparison of Room Air Versus Carbon Dioxide TechniquesJames L. Patrick, Joshua Bakke, David H. Kim, Meghan G. Lubner, Perry J. Pickhardt

Background Gaseous distention of the colon for colonoscopy, whether optical or virtual,can be achieved using room air or carbon dioxide. For CT colonography (CTC), low-pressurecarbon dioxide has been shown to decrease post-procedural discomfort, decrease perforationrisk, and may also improve colonic distention over room air, according to subjective readerstudies. A novel tool at CTC now allows for automated calculation of colonic gas and fluidvolumes, allowing for objective assessment of colonic distention. Aim To objectively comparecolonic distention at CT colonography (CTC) achieved with manual room air versus auto-mated low-pressure carbon dioxide using a novel automated volumetric quality assessmenttool. Methods Volumetric analysis was performed on CTC studies in 300 total asymptomaticadults using a novel quality tool (V3D Colon beta version, Viatronix). Colonic distentionwas achieved with room air self-administered to tolerance via hand-held pump (mean numberof pumps, 39 ± 32) in 150 individuals (mean age, 59 years; 98 men, 51 women) and viacontinuous low-pressure automated infusion of carbon dioxide in 150 individuals (meanage, 57 years; 89 men, 61 women). CTC studies were assessed to determine total colonicvolume of both luminal gas and fluid, utilizing the patient position with the best overalldistention. Colonic length along the automated centerline was also recorded to provide foradjustment according to differences in total colonic length. Results The mean total colonicvolume (± SD) for individuals receiving room air and carbon dioxide distention was 1810.5± 513.7 mL and 2222.7 ± 686.3 mL, respectively (p<0.0001). The prone position was betterdistended in 78.7% (118/150) of cases using room air, whereas the supine was better in66.0% (99/150) of carbon dioxide cases (p<0.0001). Mean colonic length for the room airand carbon dioxide cohorts was 180.5 cm and 191.2 cm, respectively. The mean length-adjusted colonic volume (mL/cm) for the room air and carbon dioxide techniques was 9.9± 2.4 mL/cm and 11.6 ± 2.6 mL/cm (p<0.0001). Conclusions 1. Continuous low-pressureautomated infusion of carbon dioxide provides greater overall colonic distention than themanual room air technique at CTC, which should result in improved diagnostic performancefor lesion detection. 2. The supine position tends to demonstrate better distention with carbondioxide, whereas the prone position is usually better distended with room air technique. 3.The automated tool employed in this study can provide an objective assessment of bothgas and fluid volumes within the colon, which can provide valuable quality assessments ofboth distention and bowel preparation.

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3D colon map from CTC case using continuous low-pressure carbon dioxide. The automatedvolumetric tool used in this study rapidly derives the total colonic volume, including specificgas and fluid volumes. This allows for objective assessment of luminal distention.

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Endoscopic Retrograde Appendicography: An Efficiency Diagnostic Method forAcute AppendicitisBing-Rong Liu, Xiao Ma, Jitao Song

Abstract Background: Appendicography had been used for the diagnosis of chronic appendici-tis. But, to our knowledge, there is no study about endoscopic retrograde appendicography(ERA) for the diagnosis of acute appendicitis (AA). Aim and method: This retrospectivestudy was designed to describe the ERA features of appendicitis and determine the viabilityfor diagnosis of AA. Patients with suspected AA were enrolled and ERA findings andcomplications were analyzed retrospectively. Results: Thirty-three consecutive patients (20men and 13 women, average age 43.2±18.1) with suspected AA (the median of Alvaradoscores 7) were undertaken ERA and the success rate of appendiceal cannulation was 96%.Twenty-three patients (70%) were definitely diagnosed with AA through ERA. Twenty-onepatients became asymptomatic after endoscopic therapy and follow-up (median 12 months;2 month to 46 months) confirmed complete recovery in 19 patients. Appendectomy andhistological results also confirmed AA in 4 patients for unrelieved or recurrent pain. Accord-ingly, the diagnostic accuracy of ERA was 100%. Interestingly, of the 23 patients, thediagnosis of Ultrosonography or CT scan was negative or equivocal in 7 patients (false-negative rate: 31% and 31%) and 4 patients were misdiagnosed as AA by US or CT scan(false-positive rate: 57% and 33%). In 23 patients with AA, colonoscopic findings showedmucosal hyperemia and edema of appendiceal orifice (83%), pus outpouring from appendi-ceal orifice (70%) and swollen surrounding mucosa in cecum (61%). Appendicographicfindings included diffuse dilatation (diameter: 0.8±0.4mm), partial stenosis (43%), inflexibil-ity (87%) and filling-defect sign (22%). During follow-up, there were no long-term complica-tions in all of the patients during or after ERA. Conclusions: ERA is a useful method forvisualization of apendiceal lumen which provided an alternative diagnostic method for AA,however, a prospective controlled study need to be performed subsequently.

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Computer Aided Diagnosis Using Narrow Band Imaging (NBI) - A NovelObjective Tool for Differentiating Non-Dysplastic and Dysplastic Barrett'sEsophagus (BE)Raymond E. Kim, Prashanth Vennalaganti, Alessandro Repici, Sravanthi Parasa, NeilGupta, Ajay Bansal, Prateek Sharma

Background: NBI has been widely evaluated in patients with BE and pit patterns have beenobserved that can differentiate non dysplastic BE (NDBE) from high grade dysplasia (HGD)/cancer. However, its diagnostic value has been challenged since it relies on the observer'ssubjective judgment and experience. Computer aided diagnosis using digital image analysismay provide objective data to improve diagnostic accuracy and consistency. Aim: To deter-mine image analysis parameters that can assist in the objective differentiation of NDBE fromHGD. Methods: NBI images of BE with HGD and without dysplasia were obtained from aprospectively maintained BE database. Multiple parameters were used to analyze each groupof images: 1) Intensity (mean color RGB value), 2) intensity SD (standard deviation of the

S-768AGA Abstracts

intensity), 3) margination (relative distribution of region intensity between the center andthe margin; algorithm developed by Ian T. Young, Pattern Recognition Group Delft University,Technology Department of Applied Physics, Netherlands), and 4) heterogeneity (dendriticnumber/length and percentage of the pixels in the object that are more than 10% of thedynamic range away from the mean intensity for that object). All analysis was done usingImage Pro Premier software (version 9.1; Media Cybernetics, Rockville, MD). Measuredparameters were compared with an unpaired t-test. Results: A total of 25 high definitionNBI images were analyzed (12 HGD and 13 NDBE). Patients in the HGD group hadsignificantly higher heterogeneity (0.45 vs 0.3; p<0.05) and standard deviation of intensity(33.43 vs 25.52; p<0.05) as compared to the NDBE group (Table). However, there wereno differences between the HGD and NDBE groups with respect to mean color RGB value(intensity) and margination (relative distribution of region intensity between the center andthe margin). Sub-RGB channel analysis also did not reveal significant differences (Table).Conclusion: The results of this pilot project show that measurements of heterogeneity andintensity SD can objectively differentiate areas of HGD from NDBE using image analysis -a novel tool for computer aided diagnosis. Further refinements in this field may add to theclinical value of NBI in dysplasia detection in BE.

Tu1156

Detailed Analysis of Predictors for Surgicial Resection in Patients WithPancreatic Cystic Lesions Undergoing Endoscopic Ultrasound With andWithout Fine Needle Aspiration: Results From a Large Multicenter CohortStudyPhillip S. Ge, Joseph W. Keach, Srinivas Gaddam, Daniel Mullady, Norio Fukami, V.Raman Muthusamy, Steven A. Edmundowicz, Riad R. Azar, Raj J. Shah, Faris Murad,Vladimir M. Kushnir, Rabindra R. Watson, Kourosh F. Ghassemi, Alireza Sedarat, Brian C.Brauer, Roy D. Yen, Stuart K. Amateau, Lindsay Hosford, Timothy Donahue, Richard D.Schulick, Barish H. Edil, Dayna S. Early, Sachin Wani

BACKGROUND: EUS provides high resolution imaging of pancreatic cystic neoplasms. Withthe ability to sample cyst fluid for cytology and tumor markers, EUS plays an integral rolein differentiating mucinous (MCN) from non-mucinous cystic neoplasms (NMCN). Thereare limited data exploring the role of EUS-FNA in the decision to recommend surgicalresection versus surveillance. AIMS: In a large multicenter cohort of patients with pancreaticcystic lesions undergoing EUS, to determine predictors of surgical resection. METHODS:This is a multicenter outcomes project of all patients undergoing EUS for evaluation ofpancreatic cystic lesions at 3 tertiary referral centers. Consecutive patients who underwentEUS with or without FNA were identified. Demographics, EUS characteristics (size, communi-cation with pancreatic duct, presence of mural nodule or solid mass, locularity, macrocystic/microcystic morphology, and EUS impression of pseudocyst), and FNA results (cyst fluidcarcinoembryonic antigen (CEA) levels, and cytology features of mucin, cellular atypia, orcancer) were recorded. Among patients who underwent surgery, the type of resection andthe final pathological diagnosis were recorded. Patients were categorized into two groups(surgery or surveillance) based on post-EUS recommendations. Univariate analysis wasperformed using Fisher's exact test for categorical variables and Mann-Whitney U-test forcontinuous variables. Multivariate logistic regression analysis was performed to identifypredictors for surgical resection. RESULTS: A total of 2407 patients were included in theanalysis, of which 1861 (77.6%) underwent EUS-FNA. The mean age was 63.2 years (SD14.0), with 58.2% females and 87.0% Caucasians. Surgical resection was recommended in503 patients of which 360 underwent surgery - Whipple in 140 (39%), distal pancreatectomyin 170 (47%), and others in 50 (14%) patients. Univariate analysis of demographics, EUScharacteristics and FNA results for patients referred for surgical resection or surveillance arehighlighted in Table 1. Multivariate analysis that adjusted for age and race revealed thefollowing predictors for referral to surgery: symptoms - weight loss on presentation (OR2.69); EUS morphology - presence of solid mass (OR 7.34), communication with main duct(OR 4.13), multilocular macrocystic morphology (OR 2.79); and EUS-FNA - mucin oncytology (OR 3.06) (Table 2). CONCLUSIONS: Among patients undergoing EUS for pan-creatic cysts, weight loss on presentation, EUS findings of associated solid mass, communica-tion with main branch and multilocular macrocystic morphology, and mucin on cytologywere independent predictors of referral for surgical resection. Future studies should focuson creation of risk stratification models to determine the need for surgery or enrollment insurveillance programs.