bluuebunny/crossref_metadata_2025_split huggingface dataset:
A107 WHAT SIZE CUT-OFF LEVEL SHOULD BE USED TO IMPLEMENT OPTICAL POLYP DIAGNOSIS?
Authors: Taghiakbari M , Pohl H , Djinbachian R , Anderson J , Metellus D , Barkun A N , Bouin M , von Renteln D 
Published: February 2022

Abstract

Background
The risk of advanced pathology and potential mismanagement increases with polyp size while performing optical diagnosis. We hypothesized that a lower polyp size cut-off (e.g., 1–3 mm) would be associated with a lower risk of misclassifying advanced neoplasia or even cancer when using optical diagnosis.

Aims
This study aimed to evaluate the proportion of patients undergoing inadequate surveillance intervals associated with different size cut-offs when using optical diagnosis.

Methods
In a post-hoc analysis of three prospective studies, the use of optical diagnosis was evaluated for three polyp size groups: 1–3, 1–5, and 1–10 mm. The primary outcome was the proportion of patients in which advanced adenomas were found and optical diagnosis resulted in delayed surveillance in each group. Secondary outcomes included agreements between surveillance intervals based on high-confidence optical diagnosis and pathology outcomes, reduction in histopathological examinations, and proportion of patients who could receive an immediate surveillance recommendation.

Results
We included 3374 patients (7291 polyps ≤10 mm) undergoing complete colonoscopies (median age 66.0 years, 75.2% male, 29.6% for screening). Among polyp sized 1–3 mm, 1–5 mm, and 1–10 mm, 0.5%, 0.6%, and 1.2% of polyps, respectively, were found to have advanced pathology ( P &lt;.0001). The percentage of patients with advanced adenomas and either 2- or 7- year delayed surveillance intervals (n=79) was 3.8%, 15.2%, and 25.3% for size cut-offs of 1–3, 1–5, and 1–10 mm polyps, respectively ( P&lt;.0001). Surveillance interval agreements between pathology and high-confidence optical diagnosis for the three groups were 97.2%, 95.5%, and 94.2%, respectively. In the cohort of patients in which patients with normal colonoscopy, polyps &gt;10 mm, and poor bowel preparation were excluded, the surveillance interval agreements between pathology and high-confidence optical diagnosis for the three groups were 96.2%, 93.6%, and 92.1%, respectively. Total reduction in pathology examinations for the three groups were 33.5%, 62.3%, and 78.2%, respectively. Furthermore, optical diagnosis could have allowed 41.0%, 58.2%, and 73.3% of patients, respectively, to be given immediate surveillance interval recommendations.

Conclusions
This study showed that limiting optical diagnosis to polyps 1–3 mm resulted in an excellent safety profile with a very low risk for inappropriate management of advanced adenomas, which makes routine clinical implementation of the “resect and discard” strategy feasible. Implementing a 3 mm cut-off could be a starting point for endoscopists to feel comfortable with the “resect and discard” strategy, with the potential of implementing a 5 mm cut-off, once optical diagnosis becomes more popular, and endoscopists become more comfortable with its use.

Funding Agencies
NoneNA
A116 CLINICAL OUTCOMES OF PATIENTS UNDERGOING BALLOON-ASSISTED ENDOSCOPY FOR SUSPECTED SMALL BOWEL BLEEDING
Authors: Guo J , Cave K , Halloran B , Zepeda-Gomez S 
Published: February 2022

Abstract

Background
Obscure gastrointestinal bleeding (OGIB) accounts for approximately 50% of all GI bleeds. This refers to bleeding from an unknown etiology despite initial investigations with upper endoscopy and colonoscopy, of which 75–80% is attributed to a small bowel source, also termed as small bowel bleeding. Various diagnostic and therapeutic modalities have been used to investigate sources of OGIB. Balloon-assisted enteroscopy (BAE) is a useful procedure for managing small bowel bleeding, with reported diagnostic and therapeutic rates up to 87% and 80%, respectively.

Aims
The aims of this study are to evaluate the outcomes of patients with OGIB who have undergone BAE, as well as to explore correlations between the timing of BAE and clinical outcomes.

Methods
We performed a retrospective review of 342 patients who underwent BAE at a tertiary referral centre between 2016 to 2021, of which 116 underwent evaluation for OGIB. Aside from gender and age, preprocedural variables including endoscopy indication, timing from video capsule endoscopy (VCE) and overt GI bleed were collected to allow for further stratification of data. Endoscopic variables including modality, findings, and therapeutic interventions were used to calculate diagnostic and therapeutic yields. Furthermore, the association between timing of BAE after VCE and clinical outcomes including rebleeding rate, diagnostics and therapeutic yields were assessed. All data analyses were performed with SPSS.

Results
The overall diagnostic yield was 70.3%. Patients with active overt bleeding were found to have a higher yield compared to those with occult and inactive overt bleeding (78.6% vs 72.5% vs 64.6%, respectively). Amongst all OGIB presentations, the most common findings were vascular lesions including angiodysplasia, arteriovenous malformations, and dieulafoy lesions. The majority of lesions were found within the proximal jejunum. Subgroup analysis did not show a statistically significant difference in diagnostic yields between BAE with and without prior VCE (75.9% vs 77.8, P = 0.605). The therapeutic yield was 51.1% with a higher yield found in those presenting with active overt bleeds compared to occult and inactive overt cases. Compared to BAE performed after 30 days of overt GI bleeding, those completed within 30 days was found to have a higher diagnostic and therapeutic rate (80.0% vs 60.0%, 70.0 vs 30.0%, respectively).

Conclusions
Balloon-assisted enteroscopy continues to be an effective diagnostic and therapeutic modality for the investigation of obscure gastrointestinal bleeding. Our retrospective study shows a higher diagnostic and therapeutic rate in those presenting with active overt GI bleed as well as those who underwent BAE within 30 days of overt GI bleeding

Funding Agencies
None
A126 ONCE IS BY CHANCE, TWO IS A TREND: A RECURRING FINDING WITHIN THE POST-RESECTION DEFECT
Authors: Alshihry I A , Tomaszewski M , Shahidi N C 
Published: February 2022

Abstract

Background
A 74-year-old male was referred for the management of a large non-pedunculated colorectal polyp in the transverse colon. On optical evaluation, including high-definition white-light and narrow-band imaging (NBI), a 30mm 0-IIA non-granular large non-pedunculated colorectal polyps (LNPCP) was identified with optical features in keeping with adenomatous histopathology (NBI International Colorectal Endoscopic II, Japan NBI Expert Team IIA, Kudo Pit Pattern III/IV). Endoscopic mucosal resection (EMR) was performed. During sequential tissue transection and evaluation of the expanding submucosal defect a hole with a surrounding white-cautery ring was identified in keeping with significant deep mural injury. However, on careful evaluation a cystic structure was identified with a viscous amorphous substance emanating from it. Endoscopic resection of the lesion was completed with subsequent through-the-scope mechanical clip closure of the area of concern.

Aims
case report showing unique finding of intra-cellular mucin emanating from the post-resection defect has been identified as a potential intra-procedural finding of a mucinous adenocarcinoma

Methods
Endoscopic mucosal resection of a mid transverse colon polyp

Results
Histopathology identified a villous adenoma with high-grade dysplasia with submucosal mucin and an indeterminate focus of carcinoma; highly suspicious for a mucinous adenocarcinoma. No muscularis propria was identified. After multi-disciplinary review, the patient underwent laparoscopic right hemicolectomy with no evidence of invasive disease.

Conclusions
Recently coined as the “fish-eye” polypectomy defect, intra-cellular mucin emanating from the post-resection defect has been identified as a potential intra-procedural finding of a mucinous adenocarcinoma; specifically, in an otherwise benign appearing LNPCP based on real-time optical evaluation. Herein we describe the second case in the literature. This reinforces the importance of meticulous evaluation of the post-resection defect to stratify this finding from deep mural injury. Moreover, further understanding of the clinical ramifications of this unique intra-procedural finding is needed.

Funding Agencies
None
A132 ACHALASIA FOLLOWING A SARS-COV-2 INFECTION: A CASE REPORT
Authors: Zeidan E , Desilets E , Bouin M , Maniere T 
Published: February 2022

Abstract

Background
SARS-CoV-2 is a novel virus currently causing a major pandemic. Recent studies have shown that SARS-CoV-2 has an affinity to ACE2 receptors which are present in the olfactory epithelium as well as the pulmonary and gastrointestinal (GI) systems. It is stipulated that these receptors are responsible for the entry of the virus into cells explaining the respiratory and GI symptoms of this infection. The anosmia related to COVID-19 is likely due to an aberrant immune response to the virus rather than direct damage to the olfactory epithelium. Similarly, achalasia is also believed to result from an aberrant immune response through which there is degeneration of inhibitory neurons in the myenteric plexus. In this case report, we present the first case of achalasia thought to be linked to a SARS-CoV-2 infection in contemporary literature.

Aims
We hypothesize that SARS-CoV-2 caused an aberrant immune response in our patient, leading him to develop achalasia. We hope to expose clinicians to this potential complication of COVID-19, allowing them to consider it sooner in their differential.

Methods
The patient’s file was reviewed to extract the relevant information. A second gastroenterologist’s opinion was obtained on the manometry to confirm the diagnosis of type III achalasia.

Results
A 61-year-old man with a medical history of myasthenia gravis, chronic obstructive pulmonary disease, hypothyroidism, and chronic renal failure was treated in our establishment for a SARS-CoV-2 pneumonia. He experienced new severe dysphagic symptoms, regurgitations, and lost 10 pounds during his hospitalization. He also developed anosmia and diarrhea. A CT-scan of his neck and thorax showed no extrinsic compression of his esophagus. No neoplasm was found on his gastroscopy. A barium study was then conducted showing a stagnation of contrast in the distal third of his esophagus. No relaxation of the inferior gastroesophageal sphincter was noted. A manometry was then performed and confirmed a type III achalasia. The mean lower esophageal sphincter residual pressure was elevated at 43.7 mmHg. A calculated 69% of wet swallows were premature contractions with a distal latency value less than 4.5 seconds. The mean distal contractile integral was 13613 mmHg. This corroborates the spastic nature of type III achalasia.

Conclusions
Considering that our patient developed anosmia and knowing its pathogenesis in the context of COVID-19, an inappropriate immune response to SARS-CoV-2 could have equally taken place in the esophagus. This inflammatory response might have caused the degeneration of the inhibitory neurons in the myenteric plexus responsible for the achalasia. Furthermore, given the fact that our patient had diarrhea, this suggests that the virus has a GI tropism supporting our hypothesis. We therefore believe that achalasia may be a potential complication of COVID-19.

High resolution esophageal motility study showing a type III achalasia pattern.

Funding Agencies
None
A134 UES MANOMETRIC PARAMETERS IN ESOPHAGEAL MOTILITY DISORDERS
Authors: Woo M , Randall D , Gupta M , Miles M , Li D Y , Nasser Y , Andrews C N 
Published: February 2022

Abstract

Background
Upper esophageal sphincter (UES) function may be evaluated manometrically using a solid-state high-resolution manometry (HRM) system, which allows for the measurement of manometric parameters specific to the UES. While many of these parameters have yet to be validated for use in clinical practice, there is some suggestion that there may be an association between esophageal motility and UES function.

Aims
We aimed to identify the relationship between UES manometric variables and high-resolution esophageal manometry (HREM) diagnoses.

Methods
A retrospective analysis of HREM studies was performed between 2019 and 2021. Extraction of esophageal and UES manometric variables were performed. UES manometric values of interest included: mean basal pressure (mmHg), mean residual pressure (mmHg), relaxation time-to-nadir (ms), relaxation duration (ms), and recovery time (ms). Relationships between manometric diagnosis (Chicago Classification version 3) and UES manometric variables were explored. All values are expressed a medians and group means were compared with the non-parametric Mann-Whitney U test.

Results
2119 symptomatic patients underwent HREM over the study period. Manometric diagnoses were achalasia (72 patients), esophagogastric junction outflow obstruction (286), absent contractility (108), distal esophageal spasm (53), jackhammer esophagus (32), and ineffective esophageal motility (694). 886 patients had no specific motility disorder; 643 of whom had ≤ 20% ineffective swallows and were considered symptomatic controls.
Patients with achalasia had significantly higher mean basal pressures (63.2 vs. 54.4, p = .001), mean residual pressure (3.8 vs. -1.9, p &lt; .001), relaxation-time-to-nadir (182.0 vs. 142.0, p = .005), relaxation duration (820.5 vs. 708.0, p &lt; .001) and recovery time (623.0 vs. 562, p &lt; .001) compared to control patients. Among patients with achalasia, the presence of panesophageal pressurization correlated weakly with recovery time (R2 .3, p = .03). Patients with ineffective esophageal motility had significantly higher mean basal pressures (61.7 vs. 54.0, p &lt; .001).
Among all patients, patients with incomplete bolus clearance (≥ 30%) had significantly higher UES mean basal pressure (58.9 vs. 54.6, p = .004), mean residual pressure (-.62 vs. -2, p &lt; .001), relaxation duration (724.0 vs. 707.0, p = .014) and recovery time (580 vs. 558.0, p &lt; .001).

Conclusions
Patients with achalasia may have higher basal and residual UES pressures, and slower relaxation compared to patients with normal esophageal motility. This may reflect dynamic changes of the UES in response to obstruction at the esophagogastric junction. Elevated UES pressures are also seen in patients with ineffective esophageal motility, potentially reflecting a response to poor bolus clearance. More work needs to be done to validate these parameters in clinical practice.

Funding Agencies
None
A138 TEMPORAL CHANGES IN SURVIVAL OF METASTATIC COLORECTAL CANCER PATIENTS: A POPULATION BASED STUDY
Authors: Wang C , Ghosh S , Abdelsalam O , Karachiwala H 
Published: February 2022

Abstract

Background
Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in Canada. While early screening programs and improvements in surgical and oncologic therapies have led to a steady decline in the mortality rate of CRC, survival in metastatic stage IV disease remains low. Furthermore, it is unclear which factors have the largest impact on survival leading to a wide range in quoted survival times between studies.

Aims
This study examines the impact of various disease, patient, and treatment factors on the outcomes and survival of stage IV CRC patients in Alberta, Canada from 2004–2014 and compares the survival data of this population to the most current statistics from clinical trials. It is hypothesized that survival should increase over the past decade and factors such as age, presence of comorbidities, number of metastases, and chemmotherapy regimen chosen will have significant impacts on overall survival.

Methods
A registry-based analysis was conducted identifying patients diagnosed with advanced colorectal cancer in Alberta. Specifically, we collected demographic information for patients in 3 time intervals: 2004–2006, 2008–2010, and 2012–2014. Data collected included year of diagnosis, age, sex, number of metastatic sites at diagnosis (single vs multiple), area of residence (rural vs urban), Charlson comorbidity index, and primary site of disease. The survival data from the three timeframes were compared.

Results
A total of 1476 patients were studied across the 3 time intervals. Over the three time periods examined in this study, there was essentially no clinically significant difference in the survival curves. Median survival from 2004–2006 was 22.3 months, from 2008–2010 was 24.4 months, and from 2012–2014 was 24.0 months. While median survival did increase over the 3 time periods, the improvement was not statistically significant (p=0.196). Overall survival in this cohort was 23.9 months. Patients who were &gt;68 years old or those who had multiple sites of metastases and multiple comorbidities had a worse overall survival (p&lt;0.05).

Conclusions
Despite a decade of advances in both the surgical and medical management of Stage IV CRC, the overall survival remains low. Furthermore, there remains a wide range in the quoted survival for studies performed with this cohort. This variation is almost certainly due to the heterogeneity of the study population in stage IV disease. Future studies should employ broad inclusion criteria in order to address these important gaps in the external validity of oncology trials.

Survival of Stage IV Colorectal Cancer Over One Decade (2004–2014)

Funding Agencies
None
A141 IS SURGERY STILL THE ONLY TREATMENT OPTION FOR CURABLE RECTAL CANCER?
Authors: Vuong T , Garant A , Khosrow-Khavar F , Devic S , Enger S , Boutros M , Cohen A , Miller C S , Friedman G , Galiatsatos P , Nguyen V , Benoit N , Lan Thai H , Diec H , Desgroseilliers C , Faria J , Vasilevsky C 
Published: February 2022

Abstract

Background
Rectal cancer is curable by standard surgery with Total Mesorectal Excision (TME). However, there are well known associated long-term bowel and sexual dysfunctions. Non-operative management (NOM) is an emerging treatment for patients with operable rectal cancer. There is evidence supporting dose response for tumor control in rectal adenocarcinoma.

Aims
In the era of modern technologies, Image-guided adaptive endorectal brachytherapy is a means to deliver local radiotherapy boost treatments. We explored its role in a randomized phase II/III trial (NCT03051464) for patients aiming to achieve cure without surgery. Total Mesorectal Excision (TME) free survival at 2 years was the primary endpoint. We now present the interim analysis upon accrual of the first 40 patients.

Methods
In randomized trial, patients with operable cT2-3ab N0 M0 rectal cancer received 45 Gy in 25 fractions of pelvic external beam radiotherapy (EBRT) with concurrent 5-FU/ Capecitabine. They were randomized to receive either an EBRT boost of 9 Gy in 5 fractions (Arm A), or three weekly adaptive brachytherapy boosts for a total of 30 Gy in 3 fractions (Arm B).

Results
Forty patients were included (20 per arm). The median age was 66 years; baseline characteristics were well balanced in terms of age, tumor location, T stage and tumor size (Table 1). The acute treatment related toxicities are similar as shown in table 2 but in arm B, there were two deaths: one patient died during his chemotherapy and external beam treatment from congestive heart failure and one patient from a heart attack after treatment prior to salvage TME surgery. The proportion of complete clinical response was 50% (n=10/20) in Arm A and 90% in Arm B (n=18/20). With a median follow-up of 2.2 years, local regrowth at 2 years occurred in 4/10 patients (40%) in Arm A and 4/18 patients (22%) in Arm B. TME-free survival rate at 2 years was 45.9% in Arm A and 85.1% in Arm B (p=0.0036) (Figure 1).

Conclusions
The interim analysis of this trial suggests that these two strategies of radiation dose escalation are feasible and lead to high chances of organ preservation in patients with operable rectal cancer. The Independent Monitoring Comittee (IDMC) approved the continuation of patient recruitment in the phase III study as planned.

Funding Agencies
Elekta
A144 CHRONIC DSS LEADS TO ALTERED EXPRESSION OF IRAK4/TPL2 PATHWAYS IN UC-COLONIZED MICE
Authors: Hann A , Santiago A , Galipeau H J , Constante M , Jackson K , Bercik P , Verdu E 
Published: February 2022

Abstract

Background
Ulcerative colitis (UC) is one of two forms of inflammatory bowel disease (IBD). The exact cause of IBD is unknown but altered host-microbe interactions and genetic susceptibility are involved in its pathogenesis. Many patients with IBD do not respond to biological therapies targeting single cytokines, therefore new therapies that target common immune pathways are being developed and need to be tested in relevant preclinical models. Previously we have shown that mice colonized with UC microbiota upregulated genes related to inflammation without induction of colitis compared to healthy volunteer-colonized mice. We thus investigated whether IRAK4 and TPL2-induced pathways, new therapeutic targets in development upstream of inflammatory cytokine gene activation, are upregulated in mice colonized with UC microbiota and chronic colitis.

Aims
Our aim was to characterize TPL2 and IRAK4 signalling pathways and T cell phenotypes in UC-colonized mice following chronic low-dose dextran sodium sulfate (DSS) colitis.

Methods
10-16-week-old germ-free C57BL/6 mice were colonized with fecal microbiota from a patient with UC experiencing a flare (n=16). Mice were housed in a gnotobiotic facility during the experiment. Three weeks following colonization, colitis was induced in half of the mice by three cycles (5 d each; 2.0%, 1.5% and 1.5%, respectively) of DSS in drinking water with a 5-d wash-out period between cycles. All mice were fed a control diet (7004, Teklad). Fecal samples were collected weekly. At sacrifice, disease activity (colon length, occult blood in feces, stool consistency, and spleen weight) was measured and colon tissue was collected for histological analysis and RNA sequencing. Mesenteric lymph nodes (MLNs) were acquired for flow cytometry to analyze T cell phenotypes.

Results
In UC-colonized mice, chronic low-dose DSS induced softer feces (p&lt;0.0001), shorter colon length (p&lt;0.0001), and increased spleen weight (p&lt;0.0001), compared with water treated mice. This was paralleled by detectable blood in stool, development of moderate colitis (DSS: 1.9+/-1.4 vs H2O: 0.5+/-0.2; p&lt;0.02) and higher proportion of IL-17 (p=0.003) and IFN-γ-producing T cells (p=0.06) in MLNs compared with water treated mice. RNA sequencing revealed that inflammatory genes, mainly related to the IRAK4/TPL2 pathway (e.g., Gadd45b, Socs3, Il1b), were significantly increased (p≤0.05) in the colon of mice treated with DSS compared with water.

Conclusions
When challenged with a chronic low-dose chemical injury agent, mice colonized with UC microbiota develop clinical and histological signs of colitis and upregulation of genes involved in inflammation like Gadd45b, Socs3, and Il1b. Thus, this model represents a new valuable tool for preclinical testing of new drug candidates, such as those related to the modulation of IRAK4/TPL2 pathways.

Funding Agencies
CCC