560 Risk of Early Post-Procedure Bleeding With Percutaneous Endoscopic Gastrostomy (PEG) Tube Placement in Patients Using Clopidogrel

adherence to the manufacturer’s recommendations, duodenoscopes, specifically the elevator channel, are difficult to completely clear of pathogenic bacteria. Instituting a system to prove that endoscopes were culture-negative resolved transmission of MDRBs, however, at great expense and with ongoing need to culture instruments before utilization. In high-volume ERCP centers, culturing of duodenoscopes for the presence of MDRB should be considered. Design modifications to the elevator channel and/or cleaning process should be mandated to ensure patient safety. 560 Risk of Early Post-Procedure Bleeding With Percutaneous Endoscopic Gastrostomy (PEG) Tube Placement in Patients Using Clopidogrel Umair Sohail*, Sameer Siddique, Harleen K. Chela, Samuel Jersak, Zainab Arif, Matthew L. Bechtold, Murtaza Arif Gastroenterology/Hepatology, University of Missouri-Columbia, Columbia, MO; University of Columbia-Missouri, Columbia, MO Background: PEG tube placement is considered a higher-risk endoscopic procedure for bleeding complications. However, the risk of bleeding with PEG placement in patients receiving clopidogrel is unknown. Current guidelines recommend discontinuation of clopidogrel for 7 -10 days prior to the procedure. We conducted a retrospective study to compare the rates of early post-procedure bleeding (within 48 hours) in PEG tube patients who are receiving clopidogrel compared to those not using clopidogrel. Methods: A retrospective study at a single tertiary-care center was performed after IRB approval. All adult patients who underwent PEG tube placement between January 2008 and January 2014 were included. Patient charts were reviewed for the following data: Age, gender, procedure indications, use of antiplatelet medications including clopidogrel, timing of clopidogrel administration before and after procedure, procedure-related complications, blood transfusions and need for repeat endoscopy within 48 hours of the procedure. Gastrointestinal bleeding was defined as presence of melena, hematochezia, hematemesis and unexplained drop in Hb of O2g/dL from baseline, need for blood transfusion, and endoscopic hemostasis. Results: A total of 319 patients who underwent PEG tube placement were identified consisting of 168 males and 151 females with mean age of 65.03 16.11 years and mean BMI 28.47 9.75 kg/m. Out of these, 33 patients (mean age 71.21 11.43 years) were using clopidogrel prior to the procedure. There were 286 patients (mean age 64.37 16.44 years) who were not taking clopidogrel. None of the patients in both groups developed melena, hematemesis or hematochezia within 48 hours post-procedure. Drop in Hb of O 2g/dL within 48 hours was noted in 2 patients in the clopidogrel group and 5 patients in the non-clopidogrel group (pZ0.16). Blood transfusion within 48 hours was administered in 2 patients in the clopidogrel group and 7 patients in the non-clopidogrel group (pZ0.24). None of the patients required repeat endoscopy for suspected GI bleed. Conclusion: In our study, there was no significant increase in risk of early (within 48 hours) post-procedure bleeding complications with PEG tube placement in patients using clopidogrel. 561 Use of the Boston Bowel Preparation Scale to Predict Risk of Missed Colon Polyps Audrey H. Calderwood*, Brian C. Jacobson, Jeffrey L. Williams, David A. Lieberman, Paul C. Schroy Gastroenterology, Boston University Medical Center, Boston, MA; Oregon Health & Science University, Portland, OR Background: Despite the impact of bowel preparation on the diagnostic accuracy of colonoscopy, appropriate timing of follow-up after an inadequate preparation remains unclear. We hypothesized that the Boston Bowel Preparation Scale (BBPS), which captures differences in cleanliness among colon segments, could predict the likelihood of missed polyps among pairs of colonoscopy exams. Methods: Patients aged 50-75 who underwent average-risk screening colonoscopy that included a BBPS score (C1) followed by a second colonoscopy for any indication within 3 years (C2) were identified within the Clinical Outcomes Research Initiative National Endoscopic Database. Adequacy of preparation was defined as BBPS segment scores R2 or entire exams considered “excellent,” “good,” and “adequate to exclude polypsO5 mm.” We compared findings between colon segments at C1 and C2 among patients with initial inadequate bowel preparation at C1 that was adequate at C2. Patients with adequate preparations at both C1 and C2 provided estimates for baseline polyp miss rates unrelated to bowel preparation, recognizing that C1 polyp detection rates www.giejournal.org Vol (PDR) may be unusually high due to selection bias that enriched for patients with polyps. The primary outcome was PDR and advanced PDR (defined as size O9 mm) among colon segments at C2. Results: Among the 335 eligible patients, 119 (36%) had an inadequate C1 then adequate C2; 169 (50%) had adequate C1 and C2. Table 1 shows patient characteristics. There were 591 colon segment pairs, of which 143 were inadequate and 448 adequate at C1. Adequate segment scores at C1 were associated with higher PDR (43% vs. 15%; p!0.0001) and advanced PDR (17% vs. 4%; p!0.0001) at C1 compared to inadequate scores. Segments that were inadequate at C1 were significantly more likely to be inadequate at C2 (14% vs. 3%; p! 0.0001). Among segment pairs without polyps seen at C1, those with inadequate scores at C1 had higher PDR at C2 (24% vs. 14%; PZ0.02) (Table 2). Similarly, among segment pairs with polyps or advanced polyps seen at C1, those with inadequate scores at C1 had higher advanced PDR at C2 (14% vs. 3%; PZ0.02 and 33% vs. 5%; PZ0.03, respectively). The interval polyp findings at C2 based on bowel preparation adequacy were more pronounced in proximal (right and transverse) (23% vs. 10%; PZ0.004) compared to distal (8% vs. 18%; PZ0.61) segments. In a multivariable model controlling for age, gender, baseline polyps, and lag time C1-C2, inadequate BBPS scores at C1 were associated with an increased risk of having advanced polyps at C2 (adjusted OR 7.8 [2.1-27.9]). Conclusions: BBPS segment scores are associated with interval findings at subsequent colonoscopies, suggesting they may be a useful tool in predicting missed pathology. BBPS scores may provide a rational way of determining timing of repeat colonoscopy after inadequate preparation. Table 1. Characteristics of the study sample