Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

A88 PATIENT AND PHYSICIAN PERSPECTIVE OF TELE-HEALTH IN GASTROENTEROLOGY

Background

Given the social distancing measures employed to reduce the transmission of SARS-CoV-2, tele-health has rapidly expanded and is now routinely used in new patient encounters and in follow up appointments across Canada.

Aims

To determine the patient and physician perspective towards tele-health in a gastroenterology outpatient setting.

Methods

An anonymous voluntary online survey was distributed to patients who had previously undergone at least one tele-health visit in a tertiary care gastroenterology outpatient setting. A separate online survey was distributed to gastroenterologists practising across Canada.

Results

A total of 181 patients from British Columbia (59.8% female) completed the survey. The tele-health appointment was the first visit for 21.8% of patients. Appointments occurred by phone call alone (61.4%) or by video and audio software (38.6%) and started within 5 minutes of the scheduled time in 75% of visits. Patient satisfaction with the tele-health visit was high (8.54 on a scale of 0–10; 0 completely dissatisfied, 10 extremely satisfied; IQR 8–10). Most patients did not perceive a difference in likelihood of compliance compared to a non-tele-health visit (90.6%), were not concerned about the lack of physical exam during a tele-health visit (82.4%) and did not with-hold information they would have revealed in person (88.7%). After the COVID-19 pandemic, some patients would prefer tele-heath visits (39.2%), whereas others would prefer in office visits (28.5%) and the remainder were indifferent (32.3%). Post-pandemic, most patients would prefer tele-health for follow up visits (68.4%), over tele-health for all possible visits (27.9%) or no tele-health visits (3.8%).

A total of 25 Canadian gastroenterologists (28.0% female; 60% academic practice, 40% community practice) completed a separate survey. Regarding the lack of physical exam in tele-health, 44% of physicians believed this did not affect the quality of their assessment, whereas some physicians believed it had either minimally (48%) or greatly (8%) impaired the quality of their assessment. Almost all physicians (96%) perceived that patients either appreciate tele-health as much as or more than in office visits.

Post-pandemic, most physicians (96%) supported a hybrid model of both tele-health and in office visits. Appointments for follow up of benign endoscopic pathology results (96%), follow up visits (92%), consultations prior to endoscopy (76%) were deemed to be most appropriate for tele-health. Follow up of malignant pathology results (24%) and consultations for new patients (32%) were thought to be less appropriate for tele-health visits.

Conclusions

Patient and physician satisfaction with tele-health in a Canadian outpatient gastroenterology setting is high. Most patients and physicians wish for tele-health to remain available in the post-pandemic setting.

Funding Agencies

Gastrointestinal Research Institute, Vancouver, British Columbia

A83 IMPACT OF TELEHEALTH ON MEDICATION ADHERENCE IN GASTROENTEROLOGY CHRONIC DISEASE MANAGEMENT

Background

With the COVID-19 pandemic, the demand and availability of telehealth in outpatient care has increased. Although use of telehealth has been studied and validated for various medical specialties, relatively few studies have looked at its role in gastroenterology despite burden of chronic diseases such as inflammatory bowel disease (IBD).

Aims

To assess effectiveness of telehealth medicine in gastroenterology by comparing medication adherence rate for patients seen with telehealth and traditional in-person appointment for various GI conditions.

Methods

Retrospective chart analysis of patients seen in outpatient gastroenterology clinic was performed to identify patients who were given prescription to fill either through telehealth or in-person appointment. By using provincial pharmacy database, we determined the prescription fill rate.

Results

A total of 241 patients were identified who were provided prescriptions during visit with their gastroenterologists. 128 patients were seen through in-person visit during pre-pandemic period. 113 patients were seen through telehealth appointment during COVID pandemic.

The mean age of patients in telehealth cohort was 42 years (57% male). On average patients had 10 prior visits with their gastroenterologists before index appointment, used for adherence assessment. 92% of patients were seen in follow-up, while 8% were seen in initial consultation. The majority of the patients in the telehealth cohort had IBD (89%), while the remaining 11% had various diagnoses, including functional GI disorder, gastroesophageal reflux disease, viral hepatitis, or hepatobiliary disorders. Biologic therapy was the most commonly prescribed medication (66.4%). 45 patients were provided either new medication or dose change, and 68 patients had prescription refill to continue their current medications. It took a mean of 18 days (SD = 16.2) for patients to fill their prescriptions.

Prescription fill rate for patients seen through telehealth and in-person visit were 98.2% and 89.1% (P = 0.004) respectively. Patients seen through telehealth were 6.8 times more likely to fill their prescriptions compared to the in-person counterparts (OR 6.82, CI 1.51 – 30.68, P = 0.004). When we compared adherence rate while excluding biologic therapies, the prescription fill rate was 94.7% in telehealth group and 81.4% in in-person group (OR 4.11, CI 0.88 – 19.27, P = 0.056). Due to high level of adherence, statistical analysis comparing adherent and non-adherent groups was performed but yielded insignificant results.

Conclusions

Medication adherence rate for patients seen through telehealth was higher compared to patients seen through in-patient visit in this study. Telehealth is a viable alternative for outpatient care especially for patients with chronic GI conditions such as IBD.

Funding Agencies

None

Three-dimensional decellularized tumor extracellular matrices with different stiffness as bioengineered tumor scaffolds

In the three-dimensional (3D) tumor microenvironment, matrix stiffness is associated with the regulation of tumor cells behaviors. In vitro tumor models with appropriate matrix stiffness are urgently desired. Herein, we prepare 3D decellularized extracellular matrix (DECM) scaffolds with different stiffness to mimic the microenvironment of human breast tumor tissue, especially the matrix stiffness, components and structure of ECM. Furthermore, the effects of matrix stiffness on the drug resistance of human breast cancer cells are explored with these developed scaffolds as case studies. Our results confirm that DECM scaffolds with diverse stiffness can be generated by tumor cells with different lysyl oxidase (LOX) expression levels, while the barely intact structure and major components of the ECM are maintained without cells. This versatile 3D tumor model with suitable stiffness can be used as a bioengineered tumor scaffold to investigate the role of the microenvironment in tumor progression and to screen drugs prior to clinical use to a certain extent.

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Novel 3D bioengineered tumor scaffolds with different stiffness were developed.

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Cells with different LOX expression levels were used to generate tumor tissue.

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DECM scaffold has good cytocompatibility.

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DECM with high stiffness promotes the resistance of MDA-MB-231 cells to cisplatin.

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DECM with high stiffness increases the expression of Bcl-2 and ABCB1.

MiR-33a inhibits the adipogenic differentiation of ovine adipose-derived stromal vascular fraction cells by targeting SIRT6

Adipose tissue is important for the regulation of energy balance through its metabolic, cellular, and endocrine functions. Furthermore, the excessive storage of subcutaneous fat can seriously affect the health and carcass traits of domestic animals. Stromal vascular fraction (SVF) cell adipogenic differentiation increases the number of differentiated adipocytes and plays a role in lipid deposition. The adipogenic differentiation of SVF cells is regulated by various factors, including microRNAs and cytokines. Sirt6 and miR-33a are known to be involved in metabolism and adipogenesis, respectively; however, their effects on the adipogenic differentiation of ovine SVF cells were previously unknown. Thus, the aim of this study was to investigate this. The results showed that SIRT6 is a binding target for miR-33a. Moreover, overexpression or inhibition of miR-33a was found to change the expression of SIRT6 messenger RNA and protein. Furthermore, modulating SIRT6 altered the expression of adipogenic marker genes. In addition, miR-33a and SIRT6 were found to play opposing roles in adipogenesis. Specifically, we demonstrated that miR-33a is involved in the negative regulation of ovine SVF cell adipogenic differentiation by inhibiting the expression of SIRT6. These findings reveal a key role for miR-33a and SIRT6 in adipogenesis, which will enrich our understanding of the regulatory factors associated with SVF cell adipogenic differentiation and provide a basis for further study on this process.

Extraction of Phenolics and Flavonoids from Four Hosta Species Using Reflux and Ultrasound-Assisted Methods with Antioxidant and α-Glucosidase Inhibitory Activities

The total phenolic and flavonoid contents (TPC and TFC) from the genus Hosta with antioxidant and α-glucosidase inhibitory activities were reported for the first time. Sixteen extracts from the aboveground and underground parts of the four Hosta species, including H. plantaginea, H. ventricosa, H. ensata, and H. albofarinosa, using reflux extraction (RE) and ultrasound-assisted extraction (UAE) techniques have high TPC and TFC with good antioxidant and α-glucosidase inhibitory activities. Furthermore, no significant differences on extraction yields, TPC, and TFC were found between RE and UAE techniques. Additionally, extracts from the aboveground parts of the four Hosta species had higher TPC, TFC, antioxidant, and α-glucosidase inhibitory activities compared to the underground parts by means of RE or UAE techniques. Lastly, the extracts of H. albo-marginata displayed a very remarkable α-glucosidase inhibitory activity compared to the positive control acarbose. The relationships of sixteen extracts of the four Hosta species were analyzed by RE and UAE techniques between extraction yields, TPC, TFC, antioxidant activity, and α-glucosidase inhibitory activity. The present study demonstrated that H. plantaginea, H. ventricosa, H. ensata, and H. albofarinosa could be new sources of natural antioxidants and antidiabetes for pharmaceutical and industrial purposes.

LncRNA NBR2 inhibits EMT progression by regulating Notch1 pathway in NSCLC

OBJECTIVE

The aim of this study was to identify the role of long non-coding RNA (lncRNA) NBR2 in non-small-cell lung cancer (NSCLC) and its possible molecular mechanisms.

PATIENTS AND METHODS

The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to explore lncRNA NBR2 expression in NSCLC cells and tissues. The chi-square test was used to analyze the relationship between lncRNA NBR2 expression and the clinical features of NSCLC patients. The pcDNA3.1 and pcDNA3.1-NBR2 vectors were transfected into NSCLC cells, and the proliferation and migration ability of NSCLC cells were detected using cell counting kit-8 (CCK-8) and transwell assay. The epithelial-mesenchymal transition (EMT)-related genes expression was detected by an EMT RT2 PCR array. QRT-PCR and Western blot was used to analyze the mRNA and protein levels of Notch1, Vimentin, N-cadherin, E-cadherin, HEY1, HEY2, and HEYL.

RESULTS

The expression of lncRNA NBR2 was decreased in NSCLC patients tissues, and the NSCLC patients in the NBR2 low expression group showed a poor prognosis. Meanwhile, the expression of NBR2 in patients with NSCLC was correlated with tumor size. Overexpression of NBR2 suppressed the viability and migration of NSCLC cells and the expression of Notch1 and EMT-related genes in AsPC-1 cells. Simultaneous overexpression of NBR2 and Notch1 could reverse the inhibitory effect of NBR2 on proliferation and migration of NSCLC cells.

CONCLUSIONS

LncRNA NBR2 inhibited the progression of EMT in NSCLC by regulating the Notch1 pathway.

A low-cost laboratory-based method for predicting newly diagnosed biopsy-proven diabetic nephropathy in people with type 2 diabetes

AIMS

To identify significant prognostic factors for newly diagnosed biopsy-proven diabetic nephropathy using routine laboratory measures, from which to derive a low-cost explanatory model, and to use this model to examine associations between the potential low-cost test panels and the risk of diabetic nephropathy in people with type 2 diabetes with normal kidney function.

METHOD

A population-based case-control study was undertaken to test the association between diabetic nephropathy and 47 laboratory variables using a 'hypothesis-free' strategy and five routinely recorded factors in diabetes care (BMI, systolic and diastolic blood pressure, HbA_1c , fasting glucose). Factors that were significant after Bonferroni correction were included in different test panels and used to develop diabetic nephropathy (outcome) explanatory models. Models were derived using risk-set sampling among 950 biopsy-proven diabetic nephropathy cases newly diagnosed in the period between 2012 and 2018 and among 4750 age- and gender-matched controls.

RESULTS

A total of 15 Bonferroni-corrected significant laboratory predictors in the three test panels (blood cell, serum electrolytes and blood coagulation) were identified through multivariable analysis and used to develop the three explanatory models. The optimism-adjusted C-statistics and calibration slope were 0.725 (95% CI 0.723-0.728) and 0.978 (95% CI 0.912-0.999) for the blood cell model, 0.688 (95% CI 0.686-0.690) and 0.923 (95% CI 0.706-0.977) for the serum electrolytes model, 0.648 (95% CI 0.639-0.658) and 0.914 (95% CI 0.641-1.115) for the blood coagulation model, respectively.

CONCLUSIONS

A total of 15 predictors were significantly associated with newly diagnosed biopsy-proven diabetic nephropathy in type 2 diabetes. The blood cell model appeared to be the low-cost model with the best predictive ability.

3D nanometrology of transparent objects by phase calibration of a basic bright-field microscope for multiple illumination apertures

Optical retrieval of the structure of transparent objects at the nanoscale requires adapted techniques capable of probing their interaction with light. Here, we considered a method based on calibration of the defocusing with partially coherent illumination and explored its phase retrieval capability over a wide range of illumination angles. We imaged: (1) commercial dielectric nanospheres to assess the phase calibration when measured along the optical axis, (2) custom-made nano-steps micropatterned in a glass substrate to assess the phase calibration when measured along the transversal axis, and (3) human cancer cells deposited on a glass substrate to assess the results of the calibration on complex transparent 3-dimensional samples. We first verified the model prediction in the spatial frequency domain and subsequently obtained a consistent and linear phase-calibration for illumination numerical apertures ranging from 0.1 to 0.5. Finally, we studied the dependence of the phase retrieval of a complex nanostructured object on the illumination aperture.

[Therapeutic effects of target artery infusion of verapamil and chemotherapy drugs on advanced non-small cell lung cancer]

Objective: To investigate the effects of targeted artery perfusion of verapamil and chemotherapy drugs on advanced non-small cell lung cancer (NSCLC). Methods: Sixty patients with advanced NSCLC who were admitted to the Central Hospital of Zhumadian from April 2016 to April 2018 were selected as the research subjects. They were divided into the observation group (26 cases) and the control group (34 cases) according to the treatment method. Patients in the observation group were treated with targeted artery perfusion of verapamil and chemotherapy drugs while the control group were treated with target artery perfusion of chemotherapy drugs alone.Both groups were treated continuously for more than 2 months. The short-term curative effect, adverse reactions, changes in immune function, levels of serum tumor markers and Karnofsky Performance Scale (KPS) scores before and after treatment as well as the prognosis were compared between the two groups. Results: The response rate and control rate in the observation group were 80.8% and 96.2%, higher than 55.9% and 76.5% in the control group (P<0.05). After treatment, CD4(+) levels and CD4(+) /CD8(+) in the observation group were (25.43±2.76)% and (0.88±0.11), lower than (27.56±2.79)% and (0.95±0.13) in the control group (P<0.05). After treatment, serum levels of CEA and CA50 in the observation group were (11.57±2.32)ng/ml and (16.62±3.28)U/ml, also lower than (15.87±2.66)ng/ml and (20.31±3.42)U/ml in the control group (P<0.05). There was no significant difference in adverse reactions between the two groups (P>0.05). After treatment, KPS score of the observation group was (81.44±2.76) points, higher than (79.62±2.38) points of the control group (P<0.05). The median survival time and progression-free median survival time of the observation group were 16.0 months and 7.5 months, respectively, significantly better than 10.0 months and 5.0 months of the control group (P<0.05). Conclusions: The treatment with target arterial perfusion of verapamil and chemotherapy drugs for advanced NSCLC can effectively improve the short-term curative effect, reduce serum levels of tumor markers, improve life quality and prolong the survival time. However, it has a certain inhibitory effect on the patient's immune function.

[Droplets and aerosols in dental clinics and prevention and control measures of infection]

Spraying during dental practices can generate a large number of droplets, which may transform into droplet nuclei and suspend in the air of clinic in the form of aerosol. Either droplets or aerosols may carry microorganisms and cause air contamination in the hospital, posing potential threat to the health of clinical healthcare staff and patients. The present article summarizes some basic concepts involved in bio-aerosol research and reviews literatures on intervention measures of dental clinic droplet/aerosols to clarify whether there is experimental evidence of aerosol-carrying bacteria in the existing literatures. The aim of the present review article is to provide evidence for the formulation of guidelines for infection control in dental healthcare practices during the pandemic period of infectious diseases, as well as to provide reference and scientific basis for the management and implementation of infection control measures in daily dental clinical work.

Significance of Glutamate Racemase for the Viability and Cell Wall Integrity of Streptococcus iniae

Streptococcus iniae is a pathogenic and zoonotic bacterium responsible for human diseases and mortality of many fish species. Recently, this bacterium has demonstrated an increasing trend for antibiotics resistance, which has warranted a search for new approaches to tackle its infection. Glutamate racemase (MurI) is a ubiquitous enzyme of the peptidoglycan synthesis pathway that plays an important role in the cell wall integrity maintenance; however, the significance of this enzyme differs in different species. In this study, we knocked out the MurI gene in S. iniae in order to elucidate the role of glutamate racemase in maintaining cell wall integrity in this bacterial species. We also cloned, expressed, and purified MurI and determined its biochemical characteristics. Biochemical analysis revealed that the MurI gene in S. iniae encodes a functional enzyme with a molecular weight of 30 kDa, temperature optimum at 35°C, and pH optimum at 8.5. Metal ions, such as Cu2+, Mn2+, Co2+ and Zn2+, inhibited the enzyme activity. MurI was found to be essential for the viability and cell wall integrity of S. iniae. The optimal growth of the MurI-deficient S. iniae mutant can be achieved only by adding a high concentration of D-glutamate to the medium. Membrane permeability assay of the mutant showed an increasing extent of the cell wall damage with time upon D-glutamate starvation. Moreover, the mutant lost its virulence when incubated in fish blood. Our results demonstrated that the MurI knockout leads to the generation of S. iniae auxotroph with damaged cell walls.

A80 ADVANCED ENDOSCOPIC RESECTION OF LARGE POLYPS & EARLY NEOPLASIA: OUTCOMES OF ENDOSCOPIC MUCOSAL RESECTION IN BRITISH COLUMBIA

Background

Recent advances have resulted in a new technique termed endoscopic mucosal resection (EMR). This procedure has been successful at removing large or complex polyps and achieving remission rates comparable to surgery. EMR can also be used to remove early, non-metastatic cancer and they are less invasive than surgery. However, they have been associated with their own complications, most serious of which being perforation. This procedure has recently become available in British Columbia for resection of both complex polyps and early established cancers in the colon.

Aims

Here we present patient outcomes of EMR procedures for the resection of colorectal polyps in British Columbia.

Methods

Retrospective data were collected on all EMR procedures done in Vancouver General Hospital and St. Paul’s Hospital (Vancouver, B.C.) from October 2012 (when procedure became available) to July 2019. Inclusion criteria were all adults who had undergone EMR for resection of polyps in the colon. Exclusion criteria were patients younger than 18 or patients who had EMR that resected polyps in the upper GI tract. Patients were referred to one of two endoscopists when one or more polyps suitable for EMR were identified during colonoscopy by other gastroenterologists. Collected data included patient demographics, polyp characteristics, procedure outcome, and complications.

Results

There were 211 EMR procedures performed on 182 patients (48.9% male). Patient age ranged from 27 to 86 (mean = 67.1). A total of 244 colon polyps were removed with an average size of 2.91 cm and ranged from 0.8 cm to 15 cm. Resected polyps had the following distribution: ascending colon (63.5%), transverse colon (10.2%), descending colon (5.7%), sigmoid colon (15.2%), and rectum (5.3%). Of those that reported resection type, 84.2% were piecemeal and 15.8% were en bloc. 40.9% of polyps were tubulovillous adenoma, 33.2% were tubular, 16.2% were sessile serrated, 6.4% were villous, and 3.4% were adenocarcinoma. Patients from 11 of the 211 EMR cases (5.2%) experienced post-procedure bleed and 4 of these 11 patients (36.4%) had been on anti-platelet or anti-coagulants (discontinued before procedure). Overall, patients from 51 (24.2%) EMR cases were on anti-platelet or anti-coagulants. 33 cases (15.6%) had residual polyps at the resection site that required additional endoscopic resection during follow-up and 14 patients (6.6%) required surgery. None of the EMR procedures resulted in perforation.

Conclusions

EMR is an effective minimally-invasive procedures that can be used to remove large, complicated colonic polyps and achieve long-term remission rate. The procedure has an acceptable risk profile, with complication and re-intervention rate similar or less than other procedures used to remove large, complicated polyps.

Funding Agencies

None

A89 IMPLEMENTING ENDOSCOPIC SUBMUCOSAL DISSECTION IN A WESTERN CANADIAN SETTING: OUTCOMES, LEARNING CURVE AND LOGISTICAL CONSIDERATIONS

Background

Endoscopic submucosal dissection (ESD) is an advanced resection technique for large gastrointestinal lesions. ESD was developed in Japan and is popular in countries with gastric cancer screening and a high incidence of gastric cancer. ESD has benefits over endoscopic mucosal resection (EMR) such as increased complete resection, en bloc resection and lower recurrence. However, ESD is a longer procedure and is difficult to master in countries with low incidence of early gastric neoplasia which is the ideal anatomic location for learning. There is increasing interest in using ESD techniques including hybrid ESD/EMR in western centers. Barriers include procedure time, perforation risk and challenges accumulating sufficient experience.

Aims

To present our experience implementing an ESD program in British Columbia including outcomes and logistical considerations of interest.

Methods

All ESD procedures since implementation of the program in May 2015 to July 2019 were included. Descriptive statistics and performance indicators over time are reported. All procedures were performed by a staff endoscopist after specialized training. Procedures were performed at two hospitals in British Columbia. Cases were referred from endoscopists and were assessed with dedicated endoscopy with or without endoscopic ultrasound prior to booking ESD.

Results

40 procedures were performed, though only one procedure was performed in the first year (Mean age 70, 67.5% male). ASA class ranged from 1–4 (mean 2.08). 22 lesions were gastric, 13 were rectal, with the remainder throughout the colon. Mean lesion size was 25mm in maximum dimension (interquartile range 15-30mm). 18 procedures were performed under general anesthesia and the remainder using procedural sedation. Total surgical time ranged from 22 to 398 minutes. Mean surgical time was 104 minutes, or 126 minutes including anesthesia. 50% of procedures were performed using hybrid ESD/EMR technique. R0 resection rate across all cases was 68% (60% for hybrid procedures, 80% for strict ESD). En bloc resection rate was 60%. Recurrence rate was 10%. Complication rate was 7.5% all were post-procedure bleeds requiring hospitalization. No perforations occurred. 3 patients required surgery for incomplete resection or invasive cancer on pathology, 3 required repeat endoscopic resection. Surgical time per cm of lesion improved significantly from the first 10 cases to the last 10 (time per cm resected 75 min to 32 min p&lt;0.006).

Conclusions

ESD is an effective therapy for GI neoplasia. ESD is feasible in a Canadian setting. Hybrid techniques tend to be faster though at the expense of R0 resection. Patient centered outcomes in this sample are favorable and comparable to large ESD series. Monitoring of ESD quality is critical for comparison with standard of care as experience with ESD in Canada grows.

Funding Agencies

None

[Efficacy tubular paraspinal approach and conventional semi-laminar approach in treating lumbar stenosis]

Objective: To analysis of the efficacy of tubular paraspinal approach and conventional semi-laminar approach in treating lumbar stenosis. Methods: Retrospective research of clinical data of 56 lumbar stenosis cases who were operated in neurosurgery department of first center of PLA general hospital from May 2015 to June 2018. Collecting the information of sex, age, operating time, intraoperative blood loss, postoperative duration in bed, as well as length of hospital stay of those patients. The 2 groups of cases, tubular paraspinal approach group (n=35)and semi-laminal approachgroup (n=21), compared by Japanese orthopedic association (JOA) score and visual analogue scale to assess the functional situation of the patients before operation, 1 week after operation, 1 month after operation, 6 months after operation, and the last follow up. Results: The operating time(83.1±7.3 vs 86.1±9.6 min), intraoperative blood loss(18.2±3.9 vs 40.5±13.3 ml), postoperative duration in bed(37.4±7.8 vs 63.7±15.8 h), as well as length of hospital stay (3.8±1.1 vs 6.5±2.0 d)were all obviously better in tubular paraspinal approach group than in traditional semi-laminar approach group(P<0.05). The postoperative 1 week, 1month, and 6 months JOA score (21.8±3.4, 23.6±2.4, 24.2±2.4 vs 19.9±3.7, 21.6±2.8, 22.4±2.1)and VAS (2.2±1.0, 2.0±1.1, 0.4±0.1 vs 3.1±1.2, 2.6±1.3, 0.5±0.1) were better in tubular paraspinal approach group than semi-laminar approach group (P<0.05). While at the last follow up, the JOA score and VAS were similar in the 2 groups (P>0.05) . Conclusions: In non-fusion techniques for treating lumbar stenosis, tubular paraspinal approach demonstrated less blood loss, shorter stay in bed as well as in hospital, and better symptom relief in early postoperative period than traditional semi-laminal approach. While at long term follow up, both approaches achieved satisfactory outcome.