Predictors of Insertion Depth At Double Balloon Enteroscopy (DBE)

Abstracts

Conclusions: Using strict pre-defined criteria, current guidelines, and a weighted method, we demonstrate that nitrates prophylaxis for ERCP procedures does reduce the incidence of pancreatitis. There is however no benefit in regards to prevention of mortality. Further randomized controlled studies should focus on dosing as well as routes of administration of nitrates

T1487 Colonoscopy Completion in Open Access Procedures in Ontario: A Nested Case Control Study Shane Hadlock, Lawrence Paszat, Linda Rabeneck, Drew Wilton, Rinku Sutradhar, Jill M. Tinmouth Background: Open access colonoscopy (OAC) (direct referral without prior consultation) has been advocated so as to increase efficiency and decrease wait times however, concerns have been raised about this practice with respect to precolonoscopy (CS) processes including the adequacy of informed consent, risk assessment and information about the procedure. Patients having OAC who are illinformed about their procedure may have higher rates of incomplete CS as a result of poor bowel preparation. Objectives: To determine the relationship between OAC and incomplete CS and to identify patient, physician, and institution factors associated with this practice. Methods: Our cohort comprised all adult outpatients with a first time colonoscopy in Ontario between 1997- 2007, identified using the databases housed at the Institute for Clinical Evaluative Sciences (ICES). OAC was defined as the absence of any OHIP consultation or procedure billing claims in the preceding 5 years by the physician performing the CS. Data were collected on patient age, sex, co-morbidity and income quintile, physician specialty and annual volume of CS as well as institution type (academic, community hospital or nonhospital clinic) and CS completion. Logistic regression modeling was used to identify patient, physician and institution factors associated with OAC. A nested case control study using propensity score matching was performed to determine the relationship between OAC and incomplete CS. Results: During the study period, 1,079,259 CS were performed. Rates of OAC nearly doubled during this time from 14% of CS in 1997 to 26% in 2007 (P!0.0001). Patients between 50-69 years of age (PZ0.0006), those living in higher income neighborhoods (P!0.0001) and with less co-morbidity (P!0.0001) were more likely to receive OAC. Gastroenterologists were more likely than surgeons to practice OAC (PZ 0.01). The odds of receiving OAC were 6 times greater in a non-hospital clinic than if the procedure was performed in a community hospital (P!0.0001). In the case control study, colonoscopy was more likely to be complete if the procedure was OAC (OR 1.3, 95% C.I. 1.2-1.4, P!0.0001). Conclusions: In Ontario, rates of OAC have increased substantially since 1997. Institution type was most strongly associated with OAC. Completion of CS, which is a recognized quality indicator, does not appear to be compromised by the use of OAC. Healthier, screen-eligible patients were more likely to have OAC, which may explain the association between complete CS and OAC.

standard technique. No significant effect was observed for bleeding (OR 1.09; 95% CI: 0.47-2.51, pZ0.84), time required (OR -4.59; 95% CI: -15.71-6.53, pZ0.42), number of attempts (OR -5.03; 95% CI: -13.73-3.67, pZ0.26) and pancreatic duct manipulation (OR 0.82; 95% CI: 0.33-2.03, pZ0.67). Funnel plot revealed no publication bias. Conclusions: The use of a guidewire for CBD cannulation decreases the odds of PEP and improves the rate of successful cannulation.

T1489 Level of Fellowship Training Influences Adenoma Detection Rates Stevany L. Peters, Aliya G. Hasan, Gregory L. Austin Background: Adenoma detection rate (ADR) is crucial to the success of CRC screening programs. A previously published study has looked at whether gastroenterology fellow participation during colonoscopy affects ADR, showing a significantly higher ADR when a fellow was involved . However this study involved only a small number of patients and was not able to analyze results stratified by training year. Aim: We sought to assess whether the affect of GI fellow participation on ADR differs by year of training in a large sample of screening colonoscopies. Methods: This is a retrospective review of all average risk screening colonoscopies performed during a two-year period at a single academic center. A total of 3658 procedures were performed during the study period from April 2005 to April 2007. Of these, a GI attending alone performed 2931 colonoscopies, and 727 were performed by a GI fellow supervised by an attending. Statistical analysis was performed using logistic regression adjusting for age, gender and endoscope used. Data were also analyzed by year of fellowship training. Results: Overall there was a trend toward increased ADR with fellow participation compared with GI attending alone but this was not statistically significant (ORZ1.20, 95% CI: 0.98-1.46, pZ 0.073). Similarly there was a trend toward increased overall polyp detection rate (ORZ1.17, 95% CI: 0.98-1.41) and advanced adenoma detection rate (ORZ1.33, 95%CI: 0.78-2.29) for colonoscopies peformed with a fellow compared to those performed without a fellow. The affect of fellow participation on detection rates differed greatly when results were broken down by year of fellowship training. Colonoscopies performed with third year fellows had significantly higher ADR(ORZ1.61, 95% CI: 1.28-2.04) and overall polyp detection rates (ORZ1.56, 95% CI: 1.24-1.96) compared to colonoscopies performed without fellows. Conversely, colonoscopies performed with first year fellows showed a trend for both decreased ADR and overall polyp detection rates although this was not statistically significant. Detection rates for advanced adenomas/cancers were not significantly different between training years. Conclusion: Year of fellowship training clearly impacts overall polyp detection rates and ADR, with increased rates seen for higher levels of training. This study suggests that in addition to technological advances to improve field of view and imaging, the addition of a trained second observer may greatly improve detection rates.

T1488 Guidewire Use for Prevention of Post ERCP Pancreatitis: A MetaAnalysis of Randomized Controlled Trials Abhishek Choudhary, Srinivas R. Puli, Jamal A. Ibdah, Matthew L. Bechtold

T1490 Predictors of Insertion Depth At Double Balloon Enteroscopy (DBE) G.A. Decker, Michael D. Crowell, Ananya Das, Anitha Yadav, Shabana F. Pasha, Virender K. Sharma, M. Edwyn Harrison, J. Scott Kriegshauser, Amy K. Hara, Isaac B. Malagon, Jonathan A. Leighton

Background: Deep biliary cannulation is important for performing therapeutic endoscopic biliary interventions. Success rates for CBD cannulation with conventional methods ranges from 50-90%, depending upon experience. Cannulation technique is believed to be pivotal in pathogenesis of post-ERCP pancreatitis (PEP) with multiple attempts increasing the risk. Multiple methods, including the use of guidewire, pre-cut technique, and medications are used to improve cannulation. A guidewire for selective cannulation may decrease the need to perform invasive techniques and PEP by improving cannulation rate. To date, the results for guidewire use for prevention of PEP and improving the rate of successful cannulation are conflicting. Therefore, we conducted meta-analysis to assess the role of guidewire use for prevention of PEP and improving cannulation rates. Methods: MEDLINE, Cochrane Central Register of Controlled Trials & Database of Systematic Reviews, Pub Med, and recent abstracts from major conference proceedings were searched (through 10/08). RCTs comparing guidewire with conventional methods for cannulation rate and PEP were included. Standard forms were used to extract data by two independent reviewers. The effects of guidewire use were analyzed by calculating pooled estimates of PEP, hyperamylasemia, cannulation rate, need for pre-cut sphincterotomy, and pancreatic duct manipulation. Separate analyses were performed for each outcome by using odds ratio (OR) or weighted mean difference (WMD) by fixed and random effects models. Publication bias was assessed by funnel plots. All studies were graded by Jadad score. Heterogeneity among studies was assessed by calculating I2 measure of inconsistency. Results: Six trials met inclusion criteria. Trials were of adequate quality (Jadad score R 2). Guidewire cannulation demonstrated a statistically significant decrease in the odds of PEP (OR 0.61; 95% CI: 0.40-0.93, pZ0.02), hyperamylasemia (OR 0.28; 95% CI: 0.16-0.46, p!0.01), and the need for pre-cut sphincterotomy (OR 0.62; 95% CI: 0.44-0.87, pZ0.007) with an increase in the rate of successful cannulation (OR 2.59; 95% CI: 1.08-6.19, pZ0.03) as compared to

Background: DBE enables potential visualization and therapeutic intervention of the entire small bowel. The depth of insertion is a critical determinant of successful DBE but is unpredictable and likely dependent on several patient and procedure related variables. Aims: To identify predictors of depth of insertion on DBE. Methods: With IRB approval a comprehensive prospective database was developed for all patients undergoing DBE at Mayo Clinic Arizona. Data collected included patient demographics, indications, type of anesthesia, fluoroscopy time, history of previous bowel resection, approach, depth of insertion and DBE findings. Because insertion is usually stopped once the lesion is identified, we sought to identify the variables that predicted the depth of insertion in patients in whom the suspected lesion was not identified. Potential predictor variables were evaluated using unadjusted Pearson correlation coefficients. Multivariate stepwise regression was used to evaluate linear models for the prediction of depth of insertion controlling for gender, age, approach (antegrade vs. retrograde), previous bowel resection, fluoroscopy time and supine vs. lateral position. All data were evaluated at a significance level set at p ! 0.05. Data are presented as Mean  SD. Results: 228 patients (128 male, 144 female, mean age 63 þ 16 years) underwent 272 DBE examinations (175 antegrade, 97 retrograde). The suspected lesion was not identified in 170 cases (62.5%), 55% of antegrade cases and 57% of retrograde cases (pZNS). Depth of insertion into the small bowel was 316.4  140.9 cm on antegrade DBE and 155.9  113.5 cm on retrograde DBE (PZ0.07). Univariate associations were significant between depth of insertion and antegrade approach (p!0.05), absence of previous bowel surgery (pZ0.016) and patient in the left lateral position (pZ0.018). Gender, age and use of fluoroscopy were not significant predictors of depth of insertion. In the multivariate model, the primary predictors of depth of insertion were an antegrade approach and the absence of previous bowel resection (RZ0.50, P!0.01). Gender, age, use of fluoroscopy and patient position were not predictive. Conclusions: Factors which favor a longer depth of

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Volume 69, No. 5 : 2009 GASTROINTESTINAL ENDOSCOPY AB309

Abstracts

insertion include using an antegrade approach and the absence of previous small bowel resection. When the location of a small intestinal lesion is uncertain, an antegrade approach is preferred to achieve maximal depth of insertion. Use of fluoroscopy is unlikely to increase depth of insertion and should be avoided to decrease resource utilization.

T1491 Case Series of Endoscopic Submucosal Dissection (ESD) for Early Remnant Gastric Cancer After Subtotal Gastrectomy Satoshi Mochizuki, Tomonori Yano, Shinya Tsuruta, Keiko Minashi, Hiroaki Ikematsu, Kazuhiro Kaneko, Toshihiko Doi, Atsushi Ohtsu Background: ESD for early gastric cancer (GC) is technically well established, and accepted as a less invasive treatment than gastrectomy. ESD for remnant GC is technically difficult because of the narrow working space, severe fibrosis and stapling instrument around the suture line. However, there are few reports on ESD for remnant GC. Aim: This case series was to evaluate the feasibility and efficacy of ESD for early remnant GC. Method: The indication of ESD for early GC in our institution is an intramucosal differentiated adenocarcinoma without ulceration, or with ulceration only if the tumor size is 3 cm or less in diameter. The inclusion criteria of this study were as follows. 1) Patients had previous subtotal gastrectomy. 2) One or more follow-up examinations were performed after ESD to evaluate recurrence. The procedures were as follows. 1) Marking spots were made with argon plasma coagulation (APC; APC300, Erbe, Italy) on circumference of the lesion. 2) Saline solution was injected into the submucosal (SM) layer. 3) A circumferential incision was made with an insulation-tipped knife (IT knife; Olympus, Tokyo, Japan) just outside the marking spots. 4) Direct dissection of the SM layer was made using the IT knife, and occasionally in combination with a conventional needle knife in cases of massive fibrosis in the SM layer. Experienced pathologists evaluated the specimens. If the lateral and deep margins of En Bloc resected specimen was definitely cancer free and no tumor invasion into vessel nor deep SM layer they defined that the ESD had achieved a curative resection. Results: Between Jan 2002 and Dec 2007, 865 patients with early GC underwent ESD in our institution. Seventeen patients with remnant early GC were included: 15 men and 2 women, with a median age of 68 years (range 54-80). The previous gastric resection included distal (nZ12), proximal (nZ4) and partial (nZ1) gastrectomy. The median tumor size was 11 mm (range 6-28 mm). The median duration of the ESD procedure was 60 min (range 25-165 min). En bloc resection was performed in 16 (94%) patients. Fourteen (82%) patients achieved curative resection, and the other three did not achieved because of pathological finding. ESD was interrupted and changed to strip biopsy in a patient because of technical difficulty and bleeding, however there was no case of perforation or severe bleeding requiring blood transfusion. Local recurrence was detected in a patient with noncurative resection, who was cured with a second ESD. No patient required additional total remnant gastrectomy. Conclusion: ESD for early remnant GC is technically feasible, and provides a high curative resection rate.

have normal exams (65.5% vs 30.7%) and a lower prevalence of stricture (9.4% vs 42.3%) and SR (3.7% vs 13.8%) compared to whites. 4202 (13.8%) pts had multiple endoscopies for dysphagia during the time period. Males were more likely to undergo multiple EGD’s than females (15.3% vs 12.8%, pZ0.001). Normal and EU were more frequent in single EGD. Stricture, EFI, suspected malignancy and SR were more frequent in pts undergoing multiple EGD’s (p!0.0001 for all comparisons). Conclusion: The prevalence of endoscopic findings among pts with dysphagia differs significantly by gender, age, and repeat procedure. For all pts, the most common findings in descending order were: stricture, normal, EU, SR, EFI, and suspected malignancy. For pts undergoing repeat procedure, normal and esophagitis were significantly less and all abnormal findings were significantly more common.

T1493 Endoscopy Is Safe in Patients with Upper Gastrointestinal Hemorrhage and Low Hematocrit Valeska Balderas, Luis F. Lara, Jayaprakash Sreenarasimhaiah, Shou Jiang Tang, William C. Santangelo, Samir Gupta, Don C. Rockey Background: In patients with acute upper gastrointestinal bleeding (UGIB), the standard practice is to transfuse packed red blood cells (PRBC) to a minimal hemoglobin (Hgb) of 10 g/dL or hematocrit (HCT) of 30g/dL, endpoints that are largely arbitrary (except perhaps for patients with cardiovascular comorbidities). We have observed low morbidity in patients undergoing endoscopy regardless of HCT at the time of endoscopy suggesting it is safe. Aim: To evaluate the morbidity and mortality according to the hematocrit in patients with UGIB undergoing EGD. Methods: We evaluated patients seen at Parkland Memorial Hospital from July to October 2008 with UGIB who were included in the UT Southwestern GI Bleeding Team registry. Clinical data was abstracted, including demographics, clinical history, laboratory data, blood transfusions and outcomes including death. Patients with lower GI bleeding, age under 18, or who were pregnant were excluded. Results: 108 patients (age 47.7  1.1;72 males) were identified (77 hematemesis, 30 melena, 1 hematochezia). 43 patients were transfused PRBCs. At time of endoscopy, the mean HCT was 29.4% (0.7). The HCT was O30% (mean 35.6 0/7) in 46 (43%), 25.1 to 30% in 34 (31%), 20.1 to 25 in 25 (22%), and ! 20% in 5 (4%). There were 11 (10%) deaths (8 males). Three patients died in 48 hours, 7 during the hospitalization and one in 30 days. There was no difference in the mean HCT between the patients that died and those that survived (25.5%  1.7 vs. 28.2%  0.9, pZNS). No significant difference in any outcome was noted in those with HCT less than 30% compared to those with HCT over 30% including age, gender, platelet count, units of blood transfused, Blatchford or Rockall score, history of smoking or alcohol abuse, length of hospitalization, ICU admission or duration of stay, or cardiovascular events (stroke or myocardial infarction). Conclusion: The outcome of patients presenting with an UGIB did not appear to be affected by the HCT at time of endoscopy. Moreover, the HCT at time of endoscopy was !30% in the majority (57%) of the patients in this cohort, and was ! 25% in 30/108 (28%) of patients. Mortality and morbidity were independent of the HCT at time of endoscopy. A ‘‘restrictive’’ transfusion approach may be indicated in patients with UGIH considering published data that suggests an increased mortality associated with blood transfusions.

T1492 Endoscopic Findings in Patients Presenting with Dysphagia: Analysis of a National Endoscopy Database Chaya Krishnamurthy, Kathryn Peterson, Kristen Hilden, Nora Mattek, John C. Fang

T1494 Time Trends in Colonoscopy Volume in the United States from 2002 to 2007 Sameer D. Saini, David A. Lieberman, Jennifer L. Holub, Dawn Peters, Philip Schoenfeld

Background: Dysphagia is a common indication for upper endoscopy. The different endoscopic findings are well known but the prevalence of these findings is not. There is also no data on the prevalence according to demographics or by single vs repeat EGD. Purpose: To determine the prevalence of endoscopic findings in patients (pts) presenting with dysphagia and if these findings differ with regards to age, gender, ethnicity and repeat procedure. Methods: The Clinical Outcomes Research Initiative (CORI) data base was queried from 1/2000 - 9/2006 for upper endoscopies performed for dysphagia. The overall frequency of endoscopic findings was determined and by gender, age, ethnicity and single vs. multiple procedures. Findings were grouped into normal esophagus, esophagitis/ esophageal ulcer (EU), esophageal food impaction (EFI), suspected malignancy, stricture and Schatzki ring (SR). Chi-square analysis was used to analyze categorical variables. Results: 30,377 total pts were identified. For race/ethnicity analyses, a total of 29,337 was used. Esophageal stricture was the most common finding followed by normal, EU, SR, EFI and suspected malignancy. Males were more likely to undergo multiple endoscopies than females (15.3% vs 12.8%, pZ0.001). Women were more likely to have a normal exam (37.2% vs 25.4%, p!0.0001). Men were more likely to have EU, EFI, stricture & suspected malignancy (p! 0.001 for all comparisons). The prevalence of SR among males and females was not different (p Z 0.90). Pts over 60 (vs!60) had a higher prevalence of suspected malignancy (1.3% vs 0.4%), stricture (45.9% vs 35.6%) & SR (14.7% vs 11.9%) (p!0.0001 for all comparisons). (Esophageal stricture was most common in white non-Hispanic pts compared to other ethnic groups. Asian/pacific islander pts were most likely to

Background: In 2001, Medicare instituted reimbursement for average-risk screening colonoscopy. Several studies have reported an increase in colonoscopy volume in the period immediately following this change in Medicare policy. However, it is unknown if colonoscopy volume has continued to increase in the ensuing years. The purpose of this study was to quantify changes in colonoscopy volume between 2002 and 2007. Methods: We performed a longitudinal retrospective cohort study using endoscopist- and procedure-level data from the Clinical Outcomes Research Initiative (CORI) database. All colonoscopies performed between 2002 and 2007 were eligible for inclusion in the analysis. Endoscopists performing fewer than 100 colonoscopies in any year of analysis were excluded. Data were extracted on annual colonoscopy volume for each endoscopist as well as the indication for each colonoscopy (average-risk screening or surveillance). To fully account for the multiple data points (colonoscopies) within each endoscopist (panel data), we used generalized estimating equations (GEE) rather than simple linear regression (aggregate data) to compare annual changes in colonoscopy volume. Results: 142 endoscopists performed 481,883 procedures during the time period and were included in the analysis. 85% of procedures were performed in a community/HMO setting, and 9% and 5% were performed in a VA/Military and non-VA academic setting, respectively. Common indications for colonoscopy were average-risk screening (24% of procedures) and surveillance (21%). Mean colonoscopy volume per endoscopist gradually increased between 2002 (476 colonoscopies per year (CPY)) and 2006 (616 CPY), but then decreased slightly to 574 CPY in 2007 (p!0.0001 for each year compared to 2002). In subgroup analyses by indication

AB310 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 5 : 2009

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