bluuebunny/crossref_metadata_2025_split huggingface dataset:
A121 QUANTIFYING INTER-OBSERVER VARIABILITY IN THE SEGMENTATION OF RECTAL TUMORS IN ENDOSCOPY IMAGES AND ITS EFFECTS ON DEEP LEARNING
Authors: Weishaupt L L , Vuong T , Thibodeau-Antonacci A , Garant A , Singh K S , Miller C , Martin A , Enger S 
Published: February 2022

Abstract

Background
Tumor delineation in endoscopy images is a crucial part of clinical diagnoses and treatment planning for rectal cancer patients. However, it is challenging to detect and adequately determine the size of tumors in these images, especially for inexperienced clinicians. This motivates the need for a standardized, automated segmentation method. While deep learning has proven to be a powerful tool for medical image segmentation, it requires a large quantity of high-quality annotated training data. Since the annotation of endoscopy images is prone to high inter-observer variability, creating a robust unbiased deep learning model for this task is challenging.

Aims
To quantify the inter-observer variability in the manual segmentation of tumors in endoscopy images of rectal cancer patients and investigate an automated approach using deep learning.

Methods
Three gastrointestinal physicians and radiation oncologists (G1, G2, and G3) segmented 2833 endoscopy images into tumor and non-tumor regions. The whole image classifications and the pixelwise classifications into tumor and non-tumor were compared to quantify the inter-observer variability. Each manual annotator is from a different institution.
Three different deep learning architectures (FCN32, U-Net, and SegNet) were trained on the binary contours created by G2. This naive approach investigates the effectiveness of neglecting any information about the uncertainty associated with the task of tumor delineation.
Finally, segmentations from G2 and the deep learning models’ predictions were compared against ground truth labels from G1 and G3, and accuracy, sensitivity, specificity, precision, and F1 scores were computed for images where both segmentations contained tumors.

Results
The deep-learning segmentation took less than 1 second, while manual segmentation took approximately 10 seconds per image. There was significant inter-observer variability for the whole-image classifications made by the manual annotators (Figure 1A). The segmentation scores achieved by the deep learning models (SegNet F1:0.80±0.08) were comparable to the inter-observer variability for the pixel-wise image classification (Figure 1B).

Conclusions
The large inter-observer variability observed in this study indicates a need for an automated segmentation tool for tumors in endoscopy images of rectal cancer patients. While deep learning models trained on a single observer’s labels can segment tumors with an accuracy similar to the inter-observer variability, these models do not accurately reflect the intrinsic uncertainty associated with tumor delineation. In our ongoing studies, we investigate training a model with all observers’ contours to reflect the uncertainty associated with the tumor segmentations.

Funding Agencies
CIHRNSERC
A124 INITIAL EXPERIENCES AND OUTCOMES IN LAUNCHING AN ESD PROGRAM IN CANADA
Authors: Jeyalingam T , Forbes N , Heitman S , Belletrutti P J 
Published: February 2022

Abstract

Background
Endoscopic submucosal dissection (ESD) is emerging as the preferred modality for curative resection of certain gastrointestinal lesions, yet it has a steep learning curve. Formal ESD training in Canada is limited, thus several endoscopists have sought training abroad. There are no data on the initial outcomes of ESD in Canada.

Aims
To describe the experience of a single advanced endoscopist (P.B.) who completed a mentor-apprentice model of ESD training in Europe and recently launched an ESD service in Canada.

Methods
Formal training in submucosal endoscopy was completed over a 12-month period (Sep 2018-Aug 2019) in Milan, Italy involving a stepwise progression through case observation (n=40), use of animal models (n=10), partial completion of human cases under direct supervision (n=25), and independent completion of human cases (n=19). Upon return to Calgary, AB, the program was promoted via grand rounds, an evening launch event and word-of-mouth. Patient and lesion characteristics, as well as procedure details and ESD outcomes were recorded prospectively in a database and used to complete a practice audit. Cases were divided into two timeframes (first 18 vs second 18 cases) and then compared with respect to specimen size, resection speed, R0 resection rate, and adverse event (AE) rate using the Mann-Whitney U and two-proportion Z-tests.

Results
From Nov 2019 to Sep 2021, 36 lesions were treated by ESD in 34 patients (mean (SD) age=66.5 (13.5) years). Most lesions were located in the rectum (44.4%) or stomach (41.7%); 21 (58.3%) were neoplastic, of which 5 (23.8%) were submucosal carcinomas, 11 (52.3%) were mucosal carcinomas (7 m1/Tis, 4 m2-3/T1a), and 5 (23.8%) were neuroendocrine tumors. The overall en bloc resection rate was 97.2% (35/36 lesions). In comparing the first 18 cases to the second 18 cases (Table 1), there were non-significant trends toward increases in mean specimen size (5.4 to 8.6 cm2, P=0.07) and R0 resection rate (62.5% to 84.6%, P=0.24). Resection speed increased significantly (2.97 to 6.25 cm2/hr, P=0.04), while AE rates remained the same (11.1%); namely 2 episodes of bleeding requiring repeat endoscopy in each set of cases. There were no perforations or intra-abdominal infections.

Conclusions
With appropriate training and support, ESD can be performed safely and effectively in a Canadian context. Proficiency can be expected to improve significantly within the first 2 years of independent ESD practice without compromising safety.

Funding Agencies
None
A135 DO VISCOUS SWALLOWS IMPROVE THE DIAGNOSTIC YIELD OF HIGH-RESOLUTION MANOMETRY?
Authors: Ricci M , Rodrigues D , Reed D E 
Published: February 2022

Abstract

Background
Esophageal motility disorders are diagnosed using high-resolution esophageal manometry (HR-EMS) using the Chicago Classification (CC V4.0) which is based on a series of 10 normal saline swallows (LS). Viscous swallows (VS; thickened liquid/applesauce) are often performed during esophageal manometry; however, they were not included within the framework of CC V4.0. Previous literature has suggested inconsistency between LS and VS in up to 25% of studies, yet it remains unclear whether routine use of VS offers any benefit to LS alone in diagnosing manometric abnormalities according to the CC V4.0.

Aims
To determine if the routine use of VS improves the diagnostic yield in HR-EMS

Methods
A retrospective analysis of all HR-EMS studies performed between December 2020 and July 2021 at Kingston Health Sciences Centre was completed. Demographic information including age, sex, indication for HR-EMS, surgical history, and chronic narcotic use was documented. Each study (consisting of 10 LS and 10 VS) was reviewed independently by a Gastroenterology Fellow and Neurogastroenterologist. A manometric diagnosis using CC V4.0 was made for both LS and VS. Descriptive statistics were performed.

Results
A total of 101 HR-EMS studies were reviewed (33 male, 68 female, age range 26 to 90 years). The most common indication for HR-EMS was dysphagia (87/101) with 23/101 having 2 indications, 30/101 having 3 indications, and 43/101 patients having &gt;3 indications. Prior upper GI tract surgery and chronic narcotic use was recorded in 9/101 and 8/101 patients, respectively. Two HR-EMS studies were excluded due to incomplete protocol. In total, 38.4% (38/99) had normal HR-EMS for both LS and VS. LS and VS that resulted in a CC V4.0 diagnosis were concordant in 37.4%(37/99) and discordant in 24.2% (24/99). Of the 24 discordant studies, 6 had a CC V4.0 diagnosis for LS (4 esophagogastric outflow obstruction (EGJOO), 1 ineffective esophageal motility (IEM), 1 diffuse esophageal spasm) and normal VS. Ten studies had normal LS and a CC V4.0 diagnosis for VS (9 IEM, 1 EGJOO). Eight had differing CC V4.0 diagnoses for LS and VS.

Conclusions
LS and VS resulted in concordant diagnoses in the majority of cases. However, there were discordant results in approximately 25% of cases. In nearly half of these studies, the LS was within normal limits whereas VS yielded a diagnosis of an esophageal motility disorder which may be of clinical significance to the patient’s management. The addition of VS to HR-EMS protocol may increase diagnostic yield in symptomatic patients.

Funding Agencies
None
A136 A RARE CAUSE OF AUTOIMMUNE ATROPHIC PANGASTRITIS COMPLICATED WITH GASTRIC OUTLET OBSTRUCTION
Authors: Akhtar D , Donaldson M A , Akhtar N H , Yang H , Donnellan F 
Published: February 2022

Abstract

Background
Chronic gastritis comes in two well recognized forms: environmental, which is most commonly antral or multifocal in distribution and is typically caused by Helicobacter Pylori (HP) infection, and autoimmune gastritis(AIG), which affects the corpus and fundus. Presented here is a case of autoimmune atrophic pangastritis(AIAP).

Aims
To increase awareness of a rare condition with limited data on available treatment modalities.

Methods
Case Report

Results
A 68-year old female with autoimmune hypothyroidism, presented with weight loss and elevated anti-TTG serology. Index esophagogastroduodenoscopy (EGD) biopsies demonstrated chronic non-specific gastritis limited to the antrum. Strict gluten free diet adherence was initiated. Testing for HLA revealed HLADq2 and HLADq8 negativity but HLADq2.5 positivity. Subsequent EGD showed a markedly atrophic appearing gastric body. The corresponding biopsies demonstrated persistent moderately chronic active gastritis with severe atrophy now involving the body, fundus and antrum. The biopsies were negative for HP. Notably, there was a lack of ECL-cell hyperplasia and the number of antral G cells appeared decreased. Anti-parietal cell antibody serology was positive with a titre of 1:80. Despite combination therapy with budesonide and mesalamine and treatment for HP given persistent symptoms, the patient’s course was further complicated by gastric-outlet obstruction (GOO). Urgent EGD biopsies showed pyloric stenosis requiring dilation. Endoscopic Ultrasound (EUS) guided biopsies were negative for malignancy. The patient was started on corticosteroids and azathioprine(AZA). Most recently, an EGD on AZA, continued to demonstrate severe chronic active pangastritis now with intestinal metaplasia involving the body. Corticosteroid therapy was reinitiated with a plan to start mycophenolate mofetil (MMF).

Conclusions
AIAP is a rarely described entity, not well documented in the literature. An eight patient case series reported a distinctive form of atrophic gastritis that was independent of HP infection with the absence of neuroendocrine hyperplasia that involved the body and antrum. Thyroid disease, specifically Hashimoto thyroiditis is present in about 40% of patients with AIG. Additionally, AIG progression to atrophic gastritis with intestinal metaplasia confers an increased risk for gastric adenocarcinoma in more than 10% of patients.
Limited literature exists regarding the management of AIAP. Pediatric data suggests the use of prednisone and/or azathioprine for AIAP. Furthermore, a recent case report of AIAP demonstrated clinical and endoscopic remission with MMF. Currently, no guidelines exist for the treatment, screening and monitoring of patients with AIAP. This case report presents a rare case of AIAP refractory to AZA complicated with GOO and adds to the little literature that exists.

Funding Agencies
None
A137 AN ELUSIVE GASTROINTESTINAL BLEED: A CASE OF RUPTURED CYSTIC ARTERY PSEUDOANEURYSM WITH PREVIOUS BILLROTH-II SURGERY
Authors: Jiang S X , Murray T , Leung V T , Ou G 
Published: February 2022

Abstract

Background
Cystic artery pseudoaneurysm (CAP) is a rare but potentially life-threatening cause of upper gastrointestinal (GI) bleeding and requires urgent intervention.

Aims
To describe the clinical enigma of CAP in the context of distorted anatomy and discuss management.

Methods
Case report and review of literature

Results
Case Report
A healthy 91-year-old man with a remote history of gastric ulcer perforation leading to Billroth-II surgery 40 years ago presented to a community hospital with melena. He had no abdominal pain and liver enzymes were normal. His hemoglobin was 97 g/L (from 137 g/L the month prior) with a BUN:Cr ratio of 50.6 mg/dL and white cell count of 14.4 x109/L. Upper endoscopy identified a large adherent clot in the stomach that could not be dislodged and was suspected to obscure the culprit lesion. Afferent and efferent limbs from previous Billroth-II surgery were identified but not intubated. He was managed supportively with acid suppression and blood transfusion, but his hemoglobin continued decreasing, leading to transfer to a tertiary centre. Upon arrival he had new-onset abdominal pain, rigors, and diaphoresis with a heart rate of 175 beats/minute and blood pressure of 75/40 mmHg. After resuscitation, emergent CT angiogram demonstrated acute contrast extravasation into the gallbladder in keeping with a ruptured CAP. He underwent successful coiling of the cystic artery. Following this, his abdominal pain resolved, and hemoglobin stabilized. Repeat endoscopy demonstrated Billroth-II anatomy without bleeding lesion. He was treated with antibiotics for presumed cholecystitis and discharged home for outpatient cholecystectomy.
Literature Review
CAP is a rare cause of hemobilia, described only in case reports. The complete hemobilia triad of jaundice, right upper quadrant pain, and GI bleeding is absent in the majority of cases, requiring endoscopic evaluation of the ampulla of Vater or contrast CT. The most common causes of CAP are iatrogenic from cholecystectomy, cholecystitis, gallstones, and malignancy. These mechanisms, whether through trauma or inflammation, lead to damage of the gallbladder wall and the cystic artery. Contained CAP can lead to intermittent bleeding whereas ruptured CAP causes brisk arterial bleeding, necessitating arterial embolization or emergent cholecystectomy. In cases of biliary obstruction, either from the original process or subsequent blood clot at the ampulla, ERCP can lead to successful decompression.

Conclusions
We present a case of ruptured CAP which eluded diagnosis due to diagnostic rarity, lack of clinical clues, and distorted anatomy. CAP should be considered with a history of recent cholecystectomy, acute cholecystitis, or gallstones. Maintaining an index of suspicion for rare causes of GI bleeding can ensure timely diagnosis and escalation to the appropriate level of care.

Funding Agencies
None
A166 CANNABIS USE IN CANADIAN INDIVIDUALS WITH INFLAMMATORY BOWEL DISEASE FOLLOWING LEGALIZATION OF CANNABIS
Authors: Iablokov V , Gregor J C , Chande N , Jairath V , Khanna R , Asfaha S 
Published: February 2022

Abstract

Background
Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are characterized by remitting and relapsing symptoms of abdominal pain, diarrhea, nausea, fatigue, and poor sleep. Most patients with IBD require chronic immunosuppressive therapy to maintain their disease in remission. Due to their disease chronicity, individuals often seek additional complementary or alternative medicines such as cannabis to treat their symptoms. Reports from the US show cannabis use in 12% of UC and 16% of CD patients. However, these numbers are likely underestimates given that cannabis remains illegal in many states.

Aims
The aim of our study is to evaluate the use of cannabis in a cohort of patients with IBD and to assess its association with IBD disease severity.

Methods
We conducted a prospective cohort survey of adult patients with IBD seen in tertiary care in London Health Sciences Centre. A 40-question online survey was completed by consenting patients and collected data on demographics, IBD disease history, cannabis use, and included the Short Inflammatory Bowel Disease Questionnaire (SIBDQ) as a measure of disease severity. The study was approved by the Western University Ethics Committee. Statistical analyses was performed using a Chi squared test for categorical data, and a two-tailed t-test for continuous data.

Results
Completed surveys were obtained from 210 individuals (135 individuals with CD and 75 with UC) and demographics were similar between the CD and UC cohort. Fifty-six percent of participants reported cannabis use at least once in their lifetime, with 38% of participants reporting cannabis use in the preceding 6 months. Interestingly, 46 percent of life-time cannabis users did not divulge their cannabis use to their physicians. In patients with UC, those who actively used cannabis were less likely to be on 5-ASA therapy (9 active users vs 22 non-users, p&lt;0.05). Medical therapy was otherwise similar between cannabis users and non-users. Surgical rates were similar between cannabis users and non-users amongst both IBD subtypes. With respect to the burden of disease, patients with CD reported higher rates of abdominal pain if they were active users, however, overall SIBDQ scores were not altered by cannabis use (21 user vs 20 non-user). Similarly, SIBDQ scores were similar amongst patients with UC who were cannabis users and non-users (20 user vs 16 non-user).

Conclusions
Cannabis use in patients with IBD is very common and much higher than previously reported prior to the legalization in Canada, but its use is not associated with lower disease severity based on patient reported outcomes. Our study also reveals that patients often do not report this use to their doctors so physicians must be aware of its prevalence amongst their IBD patient population.

Funding Agencies
None
A174 PERCEPTIONS OF CANNABIS USE IN WOMEN WITH INFLAMMATORY BOWEL DISEASE OF REPRODUCTIVE AGE: A CROSS-SECTIONAL STUDY
Authors: Tandon P , O’Connor K , Steinhart H , Deshpande A , Maxwell C , Huang V 
Published: February 2022

Abstract

Background
Cannabis use in inflammatory bowel disease (IBD) may lead to improvement in pain and general health perception. However, its use during pregnancy may result in adverse outcomes such as preterm birth and altered fetal brain development. It remains unknown how women with IBD perceive Cannabis use during pregnancy and whether they discuss its use with their health-care providers.

Aims
To determine practices in, and perceptions of, cannabis use during pregnancy in women with IBD of reproductive age.

Methods
Women with IBD (age 18–45) were recruited at Mount Sinai Hospital and via social media platforms. Participants anonymously completed surveys on baseline demographics and IBD characteristics. They also completed a Cannabis questionnaire which asked about current use, perceived risks during pregnancy, and discussions with health-care providers. Categorical variables were reported as frequencies and compared using the chi-square test. Continuous variables were reported as medians and compared using the Mann-Whitney U test.

Results
Sixty-four women were included, 26 (40.6%) with ulcerative colitis, 37 (57.8%) with Crohn’s disease, and 1 (1.6%) with indeterminate colitis. Nineteen (29.7%) were preconception, 40 (62.5%) were pregnant, and 5 (7.8%) were post-partum. Eleven (18.0%) patients reported current Cannabis use, 4 (6.3%) during pregnancy. Cannabis users were more likely to have discussed its use with a health-care provider compared to non-users (45.5% vs. 5.7%, p&lt;0.001) and had longer IBD duration (12.00 vs. 9.00 years, p=0.05). Twenty-five (42.4%) were unsure of the risks of Cannabis use in pregnancy, of which only two had discussed this with a health-care provider. Reasons for fear of Cannabis use included risk of fetal oxygen restriction (n=13, 20.3%), impact on brain development (n=29, 46.0%), and risk of fetal respiratory issues (n=18, 28.6%). Only eight (12.5%) patients reported having a conversation about Cannabis use during pregnancy with their health-care provider; all of whom felt its consumption was unsafe during pregnancy.

Conclusions
Many women with IBD report being unsure of risks of Cannabis use during pregnancy. With the legalization of Cannabis in Canada, it is imperative patients and health-care providers discuss the risks and benefits of its use, particularly during vulnerable times such as pregnancy.

Funding Agencies
None
A177 INADEQUATE OR EXCESSIVE GESTATIONAL WEIGHT GAIN IN INFLAMMATORY BOWEL DISEASE AND IMPACT ON PREGNANCY AND NEONATAL OUTCOMES
Authors: Nguyen D M , Tandon P , Govardhanam V , Hanna Y , Tao J J , Cepo J , Maxwell C , Huang V 
Published: February 2022

Abstract

Background
Patients with inflammatory bowel disease (IBD) are at a risk of adverse pregnancy outcomes. Prior studies have suggested that inadequate gestational weight gain is associated with preterm birth and intrauterine growth restriction.

Aims
We sought to characterize the proportion of people with IBD who gain inadequate or excessive weight during pregnancy and how this affects pregnancy and neonatal outcomes.

Methods
Pregnant patients with ulcerative colitis (UC), Crohn’s disease (CD), and inflammatory bowel disease unclassified (IBD-U) were identified retrospectively at Mount Sinai Hospital from 2016 to 2020. Total gestational weight gain (GWG) was calculated as the difference of the weight recorded at time of labor and pre-pregnancy weight. GWG was categorized as inadequate GWG, adequate GWG, and excessive GWG based on the pre-pregnancy body-mass index and standards set by the U.S. Institute of Medicine. Neonatal-related outcomes were also recorded for each patient and included preterm delivery, small for gestational age (SGA) and large for gestational age (LGA). Multiple logistic regression was used to assess the association between gestational weight gain and outcomes while controlling for maternal age, history of gestational diabetes, and preconception disease activity.

Results
225 pregnancies were included (106 UC, 115 CD, 4 IBD-U). Forty-eight patients (21.3%) had inadequate, 91 (40.4%) adequate, and 86 (38.2%) excessive GWG. People of East Asian, African, and Hispanic ethnicity were more likely to have inadequate GWG. People with inadequate GWG were more likely than those with excessive GWG to have lower preconception BMI (21.7 vs 25.5 kg/m2, P=0.001). IBD type was not associated with inadequate GWG or excessive GWG, though people with inadequate GWG were 2-fold less likely to be on anti-TNF therapy. People with excessive GWG were more likely than those with adequate GWG to have babies with higher birth weight (3,364g vs 3,132g, P=0.003). People with inadequate GWG were not at increased risk of SGA compared to those with adequate GWG (adjusted odds ratio (aOR), 1.01; 95% CI: 0.37 – 2.71, P=0.99). Those with excessive GWG were substantially less likely to have an infant with SGA (aOR, 0.23; 95% CI: 0.07 – 0.72, P=0.01). On multivariable logistic regression analysis, excessive GWG was not associated with increased odds of delivering infants with LGA (aOR, 1.46; 95% CI: 0.54 – 3.95, P=0.46). There was no association between non-adequate gestational weight gain and preterm delivery or Caesarean delivery.

Conclusions
Less than half of persons with IBD have adequate GWG during pregnancy. Inadequate GWG was not associated with poor neonatal outcomes, and excessive GWG appeared to protect against delivering infants born SGA.

Funding Agencies
None