bluuebunny/crossref_metadata_2025_split huggingface dataset:
A127 THE ROLE OF ENDOGENOUS OPIOIDS IN MITIGATING OPIOID TOLERANCE IN A PRE-CLINICAL MODEL OF IBD
Authors: Lopez Lopez C D , Jaramillo Polanco J O , Yu Y , Reed D E , Lomax A E , Vanner S 
Published: February 2020

Abstract

Background
While opioid drugs are used to treat pain in IBD patients, escalating doses can induce tolerance and paradoxical increased pain signaling. Endogenous opioids are released by immune cells during chronic colitis and have an analgesic action but it is unknown whether they can mitigate the development of tolerance to opioid drugs in IBD.

Aims
To evaluate whether endogenous opioids released during chronic inflammation prevent the development of tolerance and/or increased pain signaling following chronic morphine treatment.

Methods
Three groups of C57BL/6 mice were studied: 1) control, 2) chronic colitis induced with 3 cycles of 2% DSS (cDSS mice) and 3) chronic DSS mice injected with escalating doses of morphine on the last 7 days of DSS (10, 20, 30 mg/kg for the first 3 days, then 40mg/kg on 4 to 7 day) (cDSS-morphine mice). Ex vivo afferent nerve recordings were obtained from flat-sheet distal colon preparations (day 31) to determine their mechanosensitivity by probing with a 1g von Frey hair before and after acute morphine (1μM, 10 min perfusion). In parallel experiments, supernatants were obtained from the proximal colon and incubated overnight with isolated dorsal root ganglia (DRG) neurons from control mice. Neuronal excitability was then examined by measuring the rheobase using perforated patch clamp.

Results
In afferent nerve recordings, acute application of 1μM morphine inhibited the colonic afferent response to probing in control mice (17.86 vs 12.31 Hz; p&lt;0.05), whereas no effect of morphine was seen in cDSS mice. In cDSS-morphine mice acute morphine perfusion paradoxically increased the mean afferent response to probing (13.99 vs 17.28 Hz, p&lt;0.05). Single units were analyzed to identify how many mechanosensitive responses were increased, decreased or not affected by acute morphine perfusion. Compared to control mice, cDSS mice exhibited increased numbers of unaffected units (6/18 vs 1/14) whereas cDSS-morphine mice had decreased number of inhibited units (1/17 vs 11/14) and increased number of excited units (8/17 vs. 2/14) (Figure 1). In patch clamp recordings, colonic supernatants from cDSS mice reduced the excitability of DRG neurons (rheobase increased 28%; p&lt;0.05), however, this effect was lost in neurons incubated with cDSS-morphine supernatants.

Conclusions
Endogenous opioids released during cDSS colitis do not mitigate tolerance to chronic morphine exposure and may diminish the response to acute morphine. Moreover, the paradoxical hyperexcitable response to acute morphine induced by chronic morphine was not blocked by endogenous opioids. Our patch clamp data suggest that endogenous opioid actions are lost following chronic morphine exposure and could result from inhibition of their release from immune cells.

Funding Agencies
CCC
A138 CONCEPTUALIZING ENTRUSTMENT IN ENDOSCOPIC TRAINING
Authors: Jeyalingam T , Brydges R , Ginsburg S , McCreath G , Walsh C M 
Published: February 2020

Abstract

Background
Competency-based medical education (CBME), an educational paradigm that prioritizes development of measurable skills over time in training, is currently being instituted across North American residency training programs. A fundamental goal of CBME is entrustment – the process whereby supervisors come to trust trainees to perform specific tasks without supervision. How entrustment decisions are made with respect to endoscopic training has not been elucidated.

Aims
We aimed to: (1) identify the factors trainers consider in making endoscopic entrustment decisions and (2) characterize this entrustment decision-making process.

Methods
A qualitative, interview-based study was conducted using a constructivist grounded theory approach. A purposive sample of endoscopic trainers from across North America were recruited with representation from adult and pediatric gastroenterology, general surgery, and family medicine. Consenting trainers undertook audio-recorded, semi-structured interviews designed to elicit how they make endoscopic entrustment decisions and the factors they consider in making these decisions. Interview transcripts were analyzed using constant comparison, and themes were identified iteratively, working toward an explanatory framework that highlighted relationships among themes. Recruitment continued alongside analysis until theoretical saturation, determined as the point at which no new insights arose from the data.

Results
Twenty-three trainer interviews were conducted, comprising 8 (34.8%) with adult gastroenterologists, 7 (30.4%) with general surgeons, 6 (26.1%) with pediatric gastroenterologists, and 2 (8.7%) with family physicians. Of those interviewed, 10 (43.5%) practiced in Canada and 13 (56.5%) practiced in the United States. Interviewees conceptualized entrustment as a continuum rather than a binary (yes/no) decision. Entrustment decision-making was found to be a complex process, involving factors related to the: (1) trainee (insight into their own abilities, technical skills, nontechnical skills); (2) trainer (perceived self-competence, disposition, prioritization of trainee learning relative to competing demands); (3) trainer-trainee relationship (duration of exposure); (4) patient (acuity, comorbidity, comfort); (5) procedure (complexity); and (6) environment (time constraints, equipment, presence of anesthesiologist). These factors directly and indirectly contributed to the themes of trainee readiness, trainer comfort, and patient safety, which collectively predicted endoscopic entrustment decisions.

Conclusions
Entrustment in endoscopic training is a complex process incorporating multiple factors. Clarification of this process and identification of predictive factors informs the development of endoscopic assessment tools and curricula uniquely suited to CBME.

Funding Agencies
CAG
A145 A SUBMUCOSAL FLUID CUSHION PREVENTS MUSCLE LAYER DAMAGE DURING ARGON PLASMA COAGULATION
Authors: Belletrutti P J , Maselli R , Stabler T , Enderle M D , Repici A 
Published: February 2020

Abstract

Background
Thermal damage to the muscle layer of the gastrointestinal wall can occur during mucosal application of argon plasma coagulation (APC). This injury may be mitigated by creating a fluid cushion within the submucosal layer that physically separates the mucosa from the muscle layer and suppresses unwanted tissue temperature elevation. This in turn protects the muscle layer from thermal damage. The coagulative threshold of muscle proteins is known to be about 60°C, but there are no published systematic assessments of the minimum injection volume needed nor the ideal injectate to prevent thermal damage to the muscle layer during mucosal APC ablation.

Aims
Our aims were, firstly, to measure the final temperature inside the fluid cushion after mucosal ablation with APC and then to determine any differences in the final temperature between various injectable solutions. Secondly, we sought to determine the minimum volume of injectate required to protect the muscle layer from thermal damage.

Methods
All experiments were performed in an ex-vivo porcine gastrointestinal tract model. Five different fluids (normal saline, Glyceol, Gelafundin, Voluven and Eleview) of different volumes (range 0 - 5mL) were injected into the submucosa of the esophagus, stomach (fundus) and rectum to create a fluid cushion. APC was applied to the mucosa for a fixed duration (3s) at different power settings (ranging from 30 - 120W). Immediately after APC treatment, the final temperature was measured by placing a contact thermometer inside the fluid cushion, just on top of the muscle layer.

Results
There was no significant difference in the temperature measured at the surface of the muscle layer between elevation with normal saline, Glyceol, Gelafundin, Voluven and Eleview at all 3 tissue locations at equal injection volumes and power settings. The experiments showed that the temperature rose for each injectate with heightened power settings but also decreased with increasing volume of injected fluid. The minimum amount of fluid needed to protect the muscle layer from thermal damage was 2mL for the esophagus, stomach and rectum in the case of a power setting between 30 to 90W and 3mL in the case of 90 to 120W.

Conclusions
Normal saline and four commercially available submucosal injectates possess similar thermoregulatory effects as an insulator of the muscle layer during APC treatment. As opposed to the choice of injectate or anatomic location treated, the volume of fluid injected is the main determinant of the final temperature at the level of the muscularis propria. To reduce the likelihood of thermal damage to deeper layers of the GI tract when APC is applied, a minimum injection volume of 2mL is recommended if &lt;90W of power is utilized.

Funding Agencies
None
A152 FOREIGN BODY INGESTIONS AT A TERTIARY CARE CENTRE - A QUALITY ASSURANCE STUDY
Authors: Mullen T , Williams G 
Published: February 2020

Abstract

Background
Foreign body ingestion and esophageal food bolus impaction are common emergencies encountered by gastroenterologists. If not treated in a timely fashion these can result in significant morbidity, or even mortality. The mainstay of diagnosis and therapy is endoscopy. Guidelines regarding timing of endoscopy have been published by both the American and European Societies of Gastrointestinal Endoscopy, and both suggest emergent endoscopy, meaning within 2 to 6 hours, for complete esophageal obstructions. There is relatively sparse data regarding the endoscopic techniques used in real world practice.

Aims
This is a quality assurance study looking at the endoscopic practices at an adult tertiary care hospital in Halifax, Nova Scotia with respect to foreign body and food impaction management.

Methods
The hospital records of all patients presenting with ingested foreign bodies or esophageal food bolus impactions between May 2018 and July 2019 were included. Patients were identified by searching the call-back forms used by our department which documents all on-call endoscopy cases. This was then cross-referenced by endoscopy nursing charting which documents every endoscopy performed. Information such as demographics, obstruction type, endoscopic method of removal, complications, time between consultation and endoscopy, underlying pathology, and others were analyzed.

Results
70 cases were identified. Average patient age was 51.3 years old (range 16–96). 18 (25.7%) were female and 52 (74.3%) were male. 64 cases (91.4%) were esophageal food impactions and 6 (8.57%) were foreign body ingestions. Of the food impactions, 39 cases (60.9%) were cleared by the push/slide-by technique only and 10 (16.7%) were relieved using instruments such as snares, forceps, or nets. 15 (23.4%) passed spontaneously prior to scope, of which 7 received glucagon. An overtube was used in 1 case (0.16%). Complications occurred in 5 (7.8%) cases and included 3 mucosal tears, 2 of which required therapeutic interventions, and 2 episodes of oxygen desaturation in which the procedure was aborted. Complete obstructions occurred in 42 (65.6%) cases with average time of consultation to endoscopy of 2.4 hours. However, 3 (7.1%) cases exceeded 6 hours. The most common pathology was eosinophilic esophagitis with 20 cases (31.3%).
Ingested foreign bodies included 2 long objects, 3 sharp objects, and a cylindrical battery, and all but one were in the stomach. 5 (83.3%) cases used an overtube. No complications occurred.

Conclusions
At our institution 67/70 (95.7%) cases were performed within the timelines recommended by society guidelines. No complications occurred in the cases not performed within those time limits. An overtube was used in only one case in which a food bolus was retrieved out of the esophagus. Overall this study suggests that our centre is meeting recommended targets, however there is room for improvement.

Funding Agencies
None
A156 LOW COMPLICATION RATE IN THE OUTPATIENT INTRAJEJUNAL LEVODOPA/CARBIDOPA INTESTINAL GEL CLINICAL PROGRAM
Authors: Al Yatama N , Parker C H , Tse Y , Naranian T , Fasano A , Lang A , Liu L W 
Published: February 2020

Abstract

Background
Levodopa/carbidopa intestinal gel (LCIG) is a formulation that is delivered continuously through a percutaneous endoscopy gastro-jejunal tube (PEG-J) for the treatment of patients with advanced Parkinson’s disease (PD). LCIG significantly reduces periods of increased motor symptoms without troublesome dyskinesia. Adverse events related to this treatment have been attributed to PEG-J insertion and the device used for LCIG delivery, rather than to the LCIG preparation itself. To date, the data evaluating long-term efficacy and safety of PEG-J insertion for LCIG administration in the outpatient setting is limited.

Aims
The aim of this study is to describe short and long-term adverse events (AEs) associated with outpatient PEG-J tube insertion for LCIG administration at our centre.

Methods
A retrospective chart review was performed of all PD patients who underwent PEG-J insertion for LCIG therapy at Toronto Western Hospital from March 2011 to October 2019. All AEs associated with PEG-J insertion were collected including procedure and tube related complications, hospital admissions, emergency room (ER) visits and deaths. Data was analyzed using descriptive statistics.

Results
A total of 58 patients were identified and included in the final analysis. 37 (64%) male, with a mean age of 74 years +/-6.17. The mean duration of PD diagnosis prior to PEG-J insertion was 16.5 years +/-2.0. Mean time from PEG-J insertion to data collection was 37.5 months +/- 19.3. 30 (51%) patients had post-procedural abdominal pain or site pain. This pain improved with over the counter analgesics. 9 (16%) had possible site infection; 6 received oral antibiotics and 3 had the tube replaced. 19 (33%) developed granulation tissue, with only 2 patients requiring tube exchange. 32 (55%) had their tube removed or exchanged secondary to PEG-J malfunction. No ER visits related to the PEG-J were recorded. During the data collection period, 12 (21%) patients died for reasons unrelated to PEG-J insertion. There were no reported serious adverse events (SAEs), including post-procedure perforation, bleeding, fistula formation, development of intra-abdominal collections or buried bumper syndrome.

Conclusions
This study demonstrates the absence of serious AEs associated with outpatient PEG-J insertion for LCIG administration in patients with advanced PD. The most common short-term AE was post-procedural pain. The most common long-term AE was related to PEG-J malfunction requiring replacement. This study supports that the current method of outpatient PEG-J insertion for the administration of LCIG is safe in patients with advanced PD.

Funding Agencies
None
A158 LACK OF DIFFERENCE OF COLONIC CURVATURE IN SUPINE VERSUS PRONE PATIENT POSITIONS, IN NORMAL AND HIGH BMI INDIVIDUALS, AS ASSESSED BY QUANTITATIVE ASSESSMENT OF COMPUTED TOMOGRAPHY COLONOGRAPHY
Authors: Tan P , Laframboise J , Barr K , Anvari H , Ungi T , Fichtinger G , Scott C , Bechara R , Hookey L 
Published: February 2020

Abstract

Background
Dynamic positional changes during colonoscopy are commonly used in clinical practice, in particular moving from side to side. It has been shown to improve both adenoma detection rates as well as cecal intubation times. However, perhaps due to an additional level of inconvenience, there have been few studies comparing the anatomy and changes in colonic curvature when patients are in the prone position, which may help to prevent anterior bowing of the scope, particularly in patients with high body mass index (BMI).

Aims
To compare both the number of colonic curves and degree of change in curves with patients in supine versus prone positioning during computed tomography colonography (CTC).

Methods
75 CTC studies, obtained between January and April 2017 at Hotel Dieu Hospital in Kingston, Ontario, were screened and included based on image quality and adequacy of distention. Per standardized protocol, all patients undergoing CTC are imaged both in supine and prone positioning. Using an automated computer algorithm process developed for this study, curves were identified and measured via centerline points placed digitally through the colonic lumen, and compared between supine and prone patient positioning.

Results
75 colonographies were examined. The mean age was 68 years and 37/75 were male. BMI data was available for 56 patients, with mean BMI 29.4 (SD 5.7). There were no significant differences in total mean degrees of curvature between supine and prone positions [75.3 (SD 13.5) vs. 77.3 (SD 15.3), p=0.07], nor a significantly higher total number of curves &gt;100 degrees [4.0 (SD 2.0) vs. 4.5 (SD 2.3), p=0.14]. No significant correlation was seen between BMI and change in position (correlation factor 0.2, p=0.13).

Conclusions
No significant differences were found between the two positions during CT colonography. This certainly calls into question the strategy of starting in prone position, even in higher BMI patients. However, CT colonography doesn’t account for changes that can occur during colonoscopy, as the scope itself can dynamically affect angulations within the colon.

Funding Agencies
None
A160 THE EFFECT OF AN INSTRUCTIVE VIDEO ON THE BOWEL PREPARATION EXPERIENCE
Authors: Saraswat D K , Fung P H , Dong A , Sultanian R , Farooq O , Wong C 
Published: February 2020

Abstract

Background
Over 26000 new cases of colorectal cancer (CRC) are diagnosed each year in Canada. This number has been decreased significantly by the implementation of CRC screening that includes removal of any polyps found during colonoscopies. Despite this, approximately 1 in 4 colonoscopies are inadequate for the detection of early neoplasms due to insufficient bowel preparation prior to the colonoscopy. Consequently, there is a need to improve patient adherence to the bowel preparation protocol. Previous research has shown that enhanced education, including the methods and rationale for bowel preparation prior to a colonoscopy, improves the quality of the bowel preparation.

Aims
We hypothesised that patients with access to a replayable video explaining the bowel preparation protocol and its importance would have increased satisfaction and noninferior bowel preparations.

Methods
100 patients undergoing programmatic screening colonoscopy were randomly assigned into one of two groups. The control group was given the standard presentation currently given to patients. The experimental group was given the same presentation and also given access to an educational video. This video is based on Alberta provincial bowel preparations which have been tested and evaluated. Participants in both groups were sent a survey one day after their colonoscopy. Subjects completed a modified version of the Outpatient and Ambulatory Surgery Consumer Assessment of Healthcare Providers and Systems survey with added questions designed to assess their satisfaction with the education they received on the bowel preparation. Bowel preparation quality was assessed on a 4-point Likert scale by the endoscopist.

Results
17 participants (10 female), aged 40–72 (Mage = 60) have enrolled in the study thus far; however, most have yet to have their colonoscopy. Initial results revealed that all participants had high levels of satisfaction with the presentation they were given. Those in the control group indicated that they would have liked to have had access to a video guide to the bowel preparation before their procedure. The participant in the experimental group indicated high levels of satisfaction with this video, noting that it provided important information not available from other sources. Information on the quality of their bowel preparations is pending.

Conclusions
The use of multimedia explanations of the bowel preparation has promise in improving patient satisfaction with the bowel preparation. Further studies may guide best methods for implementing a video assisted educational model to enhance colonoscopy preparation.

Funding Agencies
The first author received an Edna Wakefield Rowe Memorial Summer Research Award from the Faculty of Medicine & Dentistry at the University of Alberta to support this work.
A161 MACROSCOPIC AND HISTOLOGY FINDINGS DURING UPPER DIGESTIVE ENDOSCOPY IN CHILDREN WITH SUSPICION OF CELIAC DISEASE AND HIGH LEVELS OF TRANSGLUTAMINASE IGA-ANTIBODY
Authors: Jantchou P , Dirks M , Grzywacz K , Marchand V , Halac U , Groleau V , Patey N , Dal Soglio D , Oligny L , Drouin E , Deslandres C 
Published: February 2020

Abstract

Background
The European Society of Pediatric Gastroenterology Hepatology and Nutrition suggests that the diagnosis of Celiac disease (CD) can be confirmed solely on the basis of clinical symptoms and bloodwork including a level of transglutaminase IgA-antibodies (TGA) ≥ 10 times the upper limit of normal (10XN). In Canada and the United States, this recommendation has not been endorsed. We recently demonstrated that TGA ≥ 10XN performed at our institution (INOVA Diagnostics’ Quanta Lite) was a reliable predictive test of villous atrophy in patients with suspicion of CD.

Aims
The aim of the present study was to investigate the rate of supplemental endoscopic or histological findings in a cohort of children with TGA ≥ 10XN and the association of these findings with clinical symptoms.

Methods
Consecutive children with suspected CD who had an endoscopy between 2011 and 2018 were included in this analysis. Data was extracted from our CD database. The macroscopic and histological findings were reported. We compared these diagnoses to the clinical symptoms.

Results
From 2011 to 2018, 405 new cases of CD were identified in our pediatric center. In total, 238 (58.7%) patients had baseline TGA levels ≥ 10XN (67.2% females, median (IQR) age 8.4 (4.8–12.2)). The median interval between the first visit to the gastroenterology unit and the endoscopy was 43.0 (21.0–78.0) days. In total, 58% of the endoscopies had macroscopic findings in the bulb (37.8 %) or the duodenum (41.5%) including a mosaic pattern, mucosal fissuring, or erythema. Seven cases (2.8%) of esophagitis were identified during endoscopy; histological analysis confirmed eosinophilic esophagitis in 3 cases (1.2%) and peptic esophagitis in 4 cases. Non-specific gastritis was present in 58 patients (24.4%) and 2 cases of Helicobacter pylori infection were identified. The biopsies showed subtotal/total villous atrophy of duodenum in 171 (71.8%) or partial villous atrophy in 51 patients (29.8 %). Ten patients (4,3%) had villous atrophy in the duodenal bulb alone, with normal biopsies of the second part of the duodenum. Abdominal pain did not correlate with gastritis or duodenitis. However, children with diarrhea had a greater prevalence of visible endoscopic inflammation in the duodenum than those without diarrhea: 53.5% vs 38.9% respectively; P= 0,037.

Conclusions
Apart from the classical features associated with CD, the supplementary diagnostic yield of endoscopy was low. There were only a few cases of additional diseases identified by the endoscopic procedure in a large cohort of children and adolescents with suspicion of CD. Therefore, these results support the no-biopsy approach in the settings of TGA ≥ 10XN using a reliable diagnostic kit.

Funding Agencies
None