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Background Surgical resection with laparoscopic gastric wedge resection is commonly conducted for local management of gastrointestinal stromal tumours (GIST). However, resection margins are often difficult to appreciate for lesions with larger endophytic components. As a result, tumour margins may be compromised or excess tissue resected. Laparoscopic endoscopic cooperative surgery (LECS) was developed in Japan to overcome these technical challenges in the resection of subepithelial lesions, including GISTs. Here, we present a case report of an early Canadian experience utilizing LECS in the management of gastric GIST. Aims To describe a case report of an early Canadian experience of LECS for the resection of a gastric GIST. Methods We performed a review of the literature and describe a case of LECS. Results We present a 70-year-old female referred to our centre for endoscopic resection of a 2.5x2.5cm histologically confirmed gastric GIST (low mitotic index and no known metastases). Repeat endoscopic evaluation at our centre confirmed a 25-30mm subepithelial lesion with both exophytic (small) and endophytic (large) components. After tumour board review, we opted for a LECS approach. In the OR, the lesion was identified endoscopically and marked with a Dual J-Knife (Olympus). The margins were injected with a combination of Voluven, methylene blue, and dilute epinephrine. A circumferential incision was then completed using standard ESD technique. The lesion was subsequently identified laparoscopically, with endoscopic guidance, along the lesser curvature. The lesser omentum was mobilized for clear visualization of the serosa around the lesion. A full thickness incision was made endoscopically along the distal aspect of lesion. Full thickness resection was continued endoscopically for one third of the circumference of the lesion until gastric insufflation became compromised. Full thickness resection was completed laparoscopically under endoscopic guidance with grossly negative margins. The defect was closed with running laparoscopic sutures. Endoscopic leak test was performed which was negative. The specimen was retrieved and follow up pathology demonstrated a GIST with low mitotic index and negative margins without tumour rupture. Conclusions In a review of the literature, LECS appears to minimize tissue resection while maintaining R0 resection rates. This technique is especially useful for subepithelial lesions with larger endophytic and transmural components. It has an excellent safety profile with a less than 5% anastomotic leak rate. As such, the literature supports LECS as a suitable procedure for gastric subepithelial lesions Funding Agencies None

Background Competence in performing polypectomy is increasingly appreciated as a colonoscopy quality metric, as incomplete resection can lead to post-colonoscopy colorectal cancer, particularly for polyps removed using piecemeal endoscopic mucosal resection (EMR). The relationship between training experiences and cognitive competence in polypectomy has not been previously described. Aims We aimed to examine associations between training and assessment experiences, self-reported comfort, and cognitive competence in polypectomy amongst recent graduates of Canadian gastroenterology training programs. Methods An online survey was distributed to recent GI graduates (≤5 years in independent practice). The survey comprised 4 sections: (1) demographics; (2) training and assessment experiences in colonoscopy, polypectomy, and EMR; (3) self-reported comfort in performing aspects of polypectomy outlined in the Direct Observation of Polypectomy Skills Assessment Tool; and (4) performance on a 22-item multiple choice quiz intended to assess cognitive competence in polypectomy (items and correct responses to which were determined a priori based on agreement of two experts). Data was analyzed using descriptive statistics and associations between predictors (demographics, training/assessment experiences, self-reported comfort) and outcomes (quiz score) were assessed using multiple linear regression. Results There were 28 survey respondents, comprising 13 (46%) who trained in advanced endoscopy, 5 (18%) in hepatology, 2 (7%) in motility, 1 (4%) in IBD, 1 (4%) in nutrition, and 6 (21%) with no advanced training. This cohort had a mean (SD) duration in independent practice of 29.0 (18.4) months. Their mean (SD) annual volume of colonoscopy, polypectomy, and EMR in independent practice was 530 (221), 182 (76), 28 (16), respectively and they had completed 525 (203) colonoscopies, 146 (92) polypectomies, and 23 (20) EMRs in their prior training. Their mean (SD) quiz score was 71.9% (13.2%). ANOVA revealed significant score differences based on fellowship history, with those trained in advanced endoscopy achieving the highest scores (81.1%, P=0.01). Multiple linear regression revealed that the number of EMRs completed during training was significantly correlated with quiz performance (B=0.60, P=0.03). Conclusions EMR experience during training appears to be associated with cognitive competence in polypectomy in independent practice. These results suggest increasing exposure to EMR in training may improve polypectomy quality amongst practicing endoscopists. Funding Agencies CAG

Humidification of inspired gas is important for patients receiving respiratory support. High-flow nasal cannula (HFNC) effectively provides temperature and humidity-controlled gas to the airway. We hypothesized that various levels of gas humidification would have differential effects on airway epithelial monolayers. Calu-3 monolayers were placed in environmental chambers at 37°C with relative humidity (RH) < 20% (dry), 69% (noninterventional comparator), and >90% (HFNC) for 4 and 8 hours with 10 L/min of room air. At 4 and 8 hours, cell viability and transepithelial resistance measurements were performed, apical surface fluid was collected and assayed for indices of cell inflammation and function, and cells were harvested for histology (n=6/condition). Transepithelial resistance and cell viability decreased over time (P<0.001) between HFNC and dry groups (P<0.001). Total protein secretion increased at 8 hours in the dry group (P<0.001). Secretion of interleukin (IL)-6 and IL-8 in the dry group was greater than the other groups at 8 hours (P<0.001). Histological analysis showed increasing injury over time for the dry group. These data demonstrate that exposure to low humidity results in reduced epithelial cell function and increased inflammation.

BACKGROUND: Hypothermia with xenon gas has been used to reduce brain injury and disability rate after perinatal hypoxia-ischemia. We evaluated xenon gas therapy effects in an in vitro model with or without hypothermia on cultured human airway epithelial cells (Calu-3). METHODS: Calu-3 monolayers were grown at an air-liquid interface and exposed to one of the following conditions: 1) 21% FiO2 at 37°C (control); 2) 45% FiO2 and 50% xenon at 37°C; 3) 21% FiO2 and 50% xenon at 32°C; 4) 45% FiO2 and 50% xenon at 32°C for 24 hours. Transepithelial resistance (TER) measurements were performed and apical surface fluids were collected and assayed for total protein, IL-6, and IL-8. Three monolayers were used for immunofluorescence localization of zonula occludens-1 (ZO-1). The data were analyzed by one-way ANOVA. RESULTS: TER decreased at 24 hours in all treatment groups. Xenon with hyperoxia and hypothermia resulted in greatest decrease in TER compared with other groups. Immunofluorescence localization of ZO-1 (XY) showed reduced density of ZO-1 rings and incomplete ring-like staining in the 45% FiO2– 50% xenon group at 32°C compared with other groups. Secretion of total protein was not different among groups. Secretion of IL-6 in 21% FiO2 with xenon group at 32°C was less than that of the control group. The secretion of IL-8 in 45% FiO2 with xenon at 32°C was greater than that of other groups. CONCLUSION: Hyperoxia and hypothermia result in detrimental epithelial cell function and inflammation over 24-hour exposure. Xenon gas did not affect cell function or reduce inflammation.