Simple model to incorporate statistical noise based on a modified hodgkin-huxley approach for external electrical field driven neural responses

Noise activity is known to affect neural networks, enhance the system response to weak external signals, and lead to stochastic resonance phenomenon that can effectively amplify signals in nonlinear systems. In most treatments, channel noise has been modeled based on multi-state Markov descriptions or the use stochastic differential equation models. Here we probe a computationally simple approach based on a minor modification of the traditional Hodgkin-Huxley approach to embed noise in neural response. Results obtained from numerous simulations with different excitation frequencies and noise amplitudes for the action potential firing show very good agreement with output obtained from well-established models. Furthermore, results from the Mann-Whitney U test reveal a statistically insignificant difference. The distribution of the time interval between successive potential spikes obtained from this simple approach compared very well with the results of complicated Pu-Thomas type methods at much reduced computational cost. This present method could also possibly be applied to the analysis of spatial variations and/or differences in characteristics of random incident electromagnetic signals.

Upper Esophageal Sphincter Dysfunction in Children with Type 1 Laryngeal Cleft after Failed Primary Cleft Repair

Changes in pharyngeal and upper-esophageal-sphincter (UES) motor dynamics contribute to swallowing dysfunction. Children with type 1 laryngeal clefts can present with swallowing dysfunction and associated symptoms which may persist even after the initial endoscopic intervention. This study sought to characterize pharyngeal and esophageal motor function in children with type 1 laryngeal clefts who had persistent presenting symptoms after their initial therapeutic intervention. We retrospectively analyzed high-resolution esophageal manometry studies of children ≤ 18 years old with type 1 laryngeal clefts who had an esophageal manometry study performed for persistent symptoms after an initial repair. A total of 16 children were found to have significantly increased UES resting pressure, UES pre- and post-swallow maximum pressures, and duration of UES contraction during swallows in comparison to nine age-matched controls of children without pharyngeal anatomical abnormalities. There was no difference between UES residual pressures or pharyngeal dynamics between the two groups. UES resting and residual pressures did not correlate with VFFS in penetration and aspiration scores of children with type 1 laryngeal clefts status post repair. Our study is the first to identify specific changes in UES motor function in patients with type 1 laryngeal cleft post initial repair.

Multiple staging investigations may not change management in patients with high-grade dysplasia or early esophageal adenocarcinoma

The clinical value of multiple staging investigations for high-grade dysplasia or early adenocarcinoma of the esophagus is unclear. A single-center prospective cohort of patients treated for early esophageal cancer between 2000 and 2019 was analyzed. This coincided with a transition period from esophagectomy to endoscopic mucosal resection (EMR) as the treatment of choice. Patients were staged with computed tomography (CT), endoscopic ultrasound (EUS) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography(PET)/CT. The aim of this study was to assess their accuracy and impact on clinical management. 297 patients with high-grade dysplasia or early adenocarcinoma were included (endoscopic therapy/EMR n = 184; esophagectomy n = 113 [of which a 'combined' group had surgery preceded by endoscopic therapy n = 23]). Staging accuracy was low (accurate staging EMR: CT 40.1%, EUS 29.6%, FDG-PET/CT 11.0%; Esophagectomy: CT 43.3%, EUS 59.7%, FDG-PET/CT 29.6%; Combined: CT 28.6%, EUS46.2%, FDG-PET/CT 30.0%). Staging inaccuracies across all groups that could have changed management by missing T2 disease were CT 12%, EUS 12% and FDG-PET/CT 1.6%. The sensitivity of all techniques for detecting nodal disease was low (CT 12.5%, EUS 12.5%, FDG-PET/CT0.0%). Overall, FDG-PET/CT and EUS changed decision-making in only 3.2% of patients with an early cancer on CT and low-risk histology. The accuracy of staging with EUS, CT and FDG-PET/CT in patients with high-grade dysplasia or early adenocarcinoma of the esophagus is low. EUS and FDG-PET/CT added relevant staging information over standard CT in very few cases, and therefore, these investigations should be used selectively. Factors predicting the need for esophagectomy are predominantly obtained from EMR histology rather than staging investigations.

A278 SEX DIFFERENCES IN THE EFFECT OF THE MICROBIOTA FROM IRRITABLE BOWEL SYNDROME PATIENTS ON ABDOMINAL PAIN

Background

Irritable bowel syndrome (IBS) is a chronic abdominal pain disorder that affects women twice as often as men. The gut microbiota has been implicated as a key player in the modulation of abdominal pain in IBS. Given this, we hypothesised that the production of pro-nociceptive mediators within the gut lumen are increased in females, and this contributes to the female predominance of IBS.

Purpose

Compare the effects of FS from male and female IBS patients on abdominal pain pathways and identify the impact of female mouse estrous cycle on abdominal pain.

Method

Fecal supernatants (FS) were perfused through murine colonic preparations while performing extracellular colonic afferent nerve recordings to measure changes in action potential frequency in response to colonic distension. Phase of estrous cycle in female mice was determined through vaginal swabs. FS from male and female IBS patients reporting low, moderate, and high levels of abdominal pain were used.

Result(s)

FS from female IBS patients (N=6) increased afferent nerve discharge (p < 0.05) whereas FS from male IBS patients has no effect (N=4). However, single unit analysis of nociceptive axons revealed that male IBS FS increased nociceptor activity in female mice taken during the proestrus/estrus stage (p < 0.05), but not female mice taken during the metestrus/diestrus stage or male mice. Further investigation found that IBS FS from female patients with high abdominal pain (N=6), but not patients with moderate (N=5) or low pain (N=3), increased visceral afferent nerve discharge by 70%. Single unit analysis of nociceptive axons showed that their activation was increased by almost 50% following FS perfusion from high abdominal pain patients only (p < 0.05). Histamine concentrations and proteolytic activity are increased in FS from female IBS patients with high abdominal pain compared to male IBS patients.

Conclusion(s)

This work suggests that luminal mediators that impact abdominal pain are increased in female IBS patients compared to male IBS patients, and females appear to be more sensitive to their pro-nociceptive effects. Together, these sex differences may contribute to the female predominance of IBS.

Disclosure of Interest

None Declared

A279 EVIDENCE OF TRANSIENT RECEPTOR POTENTIAL MELASTATIN 3 (TRPM3) CHANNEL SENSITIZATION IN A MOUSE MODEL OF COLITIS

Background

Abdominal pain is a primary symptom of inflammatory bowel disease (IBD). Opioids provide relief from IBD-associated pain, but they are addictive and associated with excess mortality in IBD patients. Thus, there is a need to develop novel therapeutics for IBD-associated pain. The mechanosensitive ion channel, transient receptor potential melastatin 3 (TRPM3) is upregulated in sensory neurons innervating inflamed tissue and contributes to pain from inflamed joints and cystitis. However, TRPM3’s role in abdominal pain has not been investigated.

Purpose

To evaluate whether TRPM3 contributes to abdominal pain using a mouse model of colitis.

Method

We used ratiometric Ca²⁺ imaging and extracellular afferent nerve recording to determine the effects of pharmacological activation or inhibition of TRPM3 on T13-L5 dorsal root ganglia (DRG) neurons and lumbar splanchnic nerves, respectively. Increased intracellular Ca²⁺ indicates neuronal excitation. Furthermore, the effects of TRPM3 activation in neurons and nerves from healthy mice and mice with dextran sulphate sodium-induced colitis were compared.

Result(s)

The TRPM3 agonists, CIM-0216 (0.1-10µM) and pregnenolone sulphate sodium (PSS; 1-300µM), concentration-dependently increased intracellular Ca²⁺ concentration in mouse DRG neurons and this was blocked using the TRPM3 inhibitor isosakuranetin (5µM; p<0.0001, Mann-Whitney Test). CIM-0216 (5µM)-induced increases in intracellular Ca²⁺ were significantly larger in neurons from mice with colitis (326±16% of baseline) compared to neurons from healthy mice (257±13% of baseline; p<0.01, Kruskal-Wallis with Dunn’s Multiple Comparison Test). The percentage of neurons responding to CIM-0216 was significantly increased in mice with colitis compared to healthy mice (79% vs 62%; p<0.001, Fischer’s Exact Test). Similarly, the percentage of neurons responding to PSS from mice with colitis was increased compared to healthy mice; however, this did not reach statistical significance (75% vs 70%, p=0.351, Fischer’s Exact Test). Furthermore, CIM-0216 (20µM)-induced change in the basal firing of lumbar splanchnic nerves was significantly increased in mice with colitis (1.23±0.24Hz) compared to healthy mice (0.60±0.14Hz, p<0.05, unpaired t-test).

Conclusion(s)

TRPM3 activation excited DRG neurons and lumbar splanchnic nerves and these excitatory effects were augmented in mice with colitis.

Disclosure of Interest

None Declared

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

Exploring dimensions of quality-of-life in survivors of stroke with communication disabilities - a brief report

BACKGROUND

People with communication disabilities post-stroke have poor quality-of-life.

OBJECTIVES

We aimed to explore the association of self-reported communication disabilities with different dimensions of quality-of-life between 90 and 180 days post-stroke.

METHODS

Cross-sectional survey data were obtained between 90 and 180 days post-stroke from registrants in the Australian Stroke Clinical Registry recruited from three hospitals in Queensland. The usual follow-up survey included the EQ5D-3L. Responses to the Hospital Anxiety and Depression Scale, and extra questions (e.g. communication disabilities) were also collected. We used χ² statistics to determine differences.

RESULTS

Overall, 244/647 survivors completed the survey. Respondents with communication disabilities (n = 72) more often reported moderate to extreme problems in all EQ5D-3L dimensions, than those without communication disabilities (n = 172): anxiety or depression (74% vs 40%, p < .001), pain or discomfort (58% vs 39%, p = .006), self-care (46% vs 18%, p < .001), usual activities (77% vs 49%, p < .001), and mobility (68% vs 35%, p < .001). Respondents with communication disabilities reported less fatigue (66% vs 89%, p < .001), poorer cognitive skills (thinking) (16% vs 1%, p < .001) and lower social participation (31% vs 6%, p < .001) than those without communication disabilities.

CONCLUSIONS

Survivors of stroke with communication disabilities are more negatively impacted across different dimensions of quality-of-life (as reported between 90 and 180 days post-stroke) compared to those without communication disabilities. This highlights the need for timely and on-going comprehensive multidisciplinary person-centered support.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Prevalence and Characteristics of Avoidant/Restrictive Food Intake Disorder in Pediatric Neurogastroenterology Patients

ABSTRACT

Recent reports document avoidant/restrictive food intake disorder (ARFID) symptoms among 13-40% of adults presenting to neurogastroenterology clinics, but ARFID in pediatrics is understudied. We conducted a retrospective review of charts from 129 consecutive referrals (ages 6-18 years; 57% female) for pediatric neurogastroenterology examination, from January 2016 through December 2018. Eleven cases (8%) met the full criteria for ARFID by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition and 19 cases (15%) had clinically significant avoidant/ restrictive eating behaviors with insufficient information for a definitive ARFID diagnosis. Of patients with ARFID symptoms (n = 30), 20 (67%) cited fear of gastrointestinal symptoms as motivation for their avoidant/ restrictive eating. Compared to patients without ARFID symptoms, patients with ARFID symptoms were older (P  < .001), more likely to be female (51% vs 79%, P  = 0.014), and more frequently presented with eating/weight-related complaints (15% vs 33%, P  = 0.026). This pilot retrospective study showed ARFID symptoms present in 23% of pediatric neurogastroenterology patients; further research is needed to understand risk and maintenance factors of ARFID in the neurogastroenterology setting.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Designing a Framework for Remote Cancer Care Through Community Co-design: Participatory Development Study

BACKGROUND

Recent shifts to telemedicine and remote patient monitoring demonstrate the potential for new technology to transform health systems; yet, methods to design for inclusion and resilience are lacking.

OBJECTIVE

The aim of this study is to design and implement a participatory framework to produce effective health care solutions through co-design with diverse stakeholders.

METHODS

We developed a design framework to cocreate solutions to locally prioritized health and communication problems focused on cancer care. The framework is premised on the framing and discovery of problems through community engagement and lead-user innovation with the hypothesis that diversity and inclusion in the co-design process generate more innovative and resilient solutions. Discovery, design, and development were implemented through structured phases with design studios at various locations in urban and rural Kentucky, including Appalachia, each building from prior work. In the final design studio, working prototypes were developed and tested. Outputs were assessed using the System Usability Scale as well as semistructured user feedback.

RESULTS

We co-designed, developed, and tested a mobile app (myPath) and service model for distress surveillance and cancer care coordination following the LAUNCH (Linking and Amplifying User-Centered Networks through Connected Health) framework. The problem of awareness, navigation, and communication through cancer care was selected by the community after framing areas for opportunity based on significant geographic disparities in cancer and health burden resource and broadband access. The codeveloped digital myPath app showed the highest perceived combined usability (mean 81.9, SD 15.2) compared with the current gold standard of distress management for patients with cancer, the paper-based National Comprehensive Cancer Network Distress Thermometer (mean 74.2, SD 15.8). Testing of the System Usability Scale subscales showed that the myPath app had significantly better usability than the paper Distress Thermometer (t63=2.611; P=.01), whereas learnability did not differ between the instruments (t63=-0.311; P=.76). Notable differences by patient and provider scoring and feedback were found.

CONCLUSIONS

Participatory problem definition and community-based co-design, design-with methods, may produce more acceptable and effective solutions than traditional design-for approaches.

Mapping the movement for climate change and health in England: a descriptive review and theory of change analysis

Aims:

There are a growing number of organisations working to address the connections between climate change and health. This article introduces the concept of ‘theories of change’ – the methodology by which organisations or movements hope to bring about social change – and applies it to the current climate change and health movement in England. Through movement mapping, the article describes and offers reflections on the climate change and health ecosystems in England.

Methods:

Organisations working on climate change and health in England were identified and publicly available information was collated to map movement characteristics, target stakeholders and methodologies deployed, using an inductive, iterative approach.

Results:

A total of 98 organisations working on health and climate change (and/or sustainability) were initially identified, of which 70 met the inclusion criteria. Most organisations target two or more stakeholders, with healthcare workers, management structures, and government being most commonly cited. Methodological approaches identified include Formal education programmes; Awareness-raising; Purchasing-procurement power; Advocacy; Financial; Media-messaging; Networking; Knowledge generation; and Policy making, of which education, awareness-raising, and advocacy are most commonly used.

Conclusion:

There is a tendency for climate change and health organisations in England to focus on individual level and sectoral change over system change. More could be made of the potential for the healthcare professions’ voice and messaging for the wider climate movement. Given the rapid boom of climate change and health organisations in recent years, a mind-set shift that recognises different players as part of a cohesive ecosystem with better coordination and collaboration may reduce unnecessary work, and facilitate more cohesive outcomes.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

Human myelomeningocele risk and ultra-rare deleterious variants in genes associated with cilium, WNT-signaling, ECM, cytoskeleton and cell migration

Myelomeningocele (MMC) affects one in 1000 newborns annually worldwide and each surviving child faces tremendous lifetime medical and caregiving burdens. Both genetic and environmental factors contribute to disease risk but the mechanism is unclear. This study examined 506 MMC subjects for ultra-rare deleterious variants (URDVs, absent in gnomAD v2.1.1 controls that have Combined Annotation Dependent Depletion score ≥ 20) in candidate genes either known to cause abnormal neural tube closure in animals or previously associated with human MMC in the current study cohort. Approximately 70% of the study subjects carried one to nine URDVs among 302 candidate genes. Half of the study subjects carried heterozygous URDVs in multiple genes involved in the structure and/or function of cilium, cytoskeleton, extracellular matrix, WNT signaling, and/or cell migration. Another 20% of the study subjects carried heterozygous URDVs in candidate genes associated with gene transcription regulation, folate metabolism, or glucose metabolism. Presence of URDVs in the candidate genes involving these biological function groups may elevate the risk of developing myelomeningocele in the study cohort.

Pan-enteric neuropathy and dysmotility are present in a mouse model of short-segment Hirschsprung disease and may contribute to post-pullthrough morbidity

PURPOSE

Hirschsprung disease (HSCR) is characterized by distal intestinal aganglionosis. While surgery is lifesaving, gastrointestinal (GI) motility disorders persist in many patients. Our objective was to determine whether enteric nervous system (ENS) abnormalities exist in the ganglionated portions of the GI tract far proximal to the aganglionic region and whether these are associated with GI dysmotility.

METHODS

Using Ednrb-null mice, a model of HSCR, immunohistochemical analysis was performed to evaluate quantitatively ENS structure in proximal colon, small intestine, and stomach. Gastric emptying and intestinal transit were measured in vivo and small and large bowel contractility was assessed by spatiotemporal mapping ex vivo.

RESULTS

Proximal colon of HSCR mice had smaller ganglia and decreased neuronal fiber density, along with a marked reduction in migrating motor complexes. The distal small intestine exhibited significantly fewer ganglia and decreased neuronal fiber density, and this was associated with delayed small intestinal transit time. Finally, in the stomach of HSCR mice, enteric neuronal packing density was increased and gastric emptying was faster.

CONCLUSIONS

ENS abnormalities and motility defects are present throughout the ganglionated portions of the GI tract in Ednrb-deficient mice. This may explain the GI morbidity that often occurs following pull-through surgery for HSCR.

Sexual Risk Behaviors Associated with Sexually Transmitted Infections in a US Military Population Living with HIV After the Repeal of "Don't Ask, Don't Tell"

Risk behaviors associated with sexually transmitted infections (STIs) among people living with HIV (PLWH) have not been well characterized in the US military. We identified risk behaviors associated with a new STI in this population after the repeal of "Don't Ask, Don't Tell." US Military HIV Natural History Study participants who completed the risk behavior questionnaire (RBQ) between 2014 and 2017 and had at least 1 year of follow-up were included (n = 1589). Logistic regression identified behaviors associated with incident STI in the year following RBQ completion. Overall, 18.9% acquired an STI and 52.7% reported condom use at last sexual encounter. Compared with those with no new sex partners, participants with between one and four or five or more new partners were 1.71 [1.25-2.35] and 6.12 [3.47-10.79] times more likely to get an STI, respectively. Individuals reporting low or medium/high perceived risk of STI were 1.83 [1.23-2.72] and 2.65 [1.70-4.15] times more likely to acquire a new STI than those reporting no perceived risk, respectively. Participants who preferred not to answer about sexual preference, number of new partners, or perceived STI risk were also more likely to acquire a new STI. Our study illustrates that despite regular access to health care and accurate perceptions of risk, rates of STI among PLWH remain high in the US military setting, as in others. Given the potential individual and public health consequences of STI coinfection after HIV, more work is needed to assess interventions aimed at sexual behavior change for PLWH.

Faire face au COVID-19, mise en place de novo d’une unité mutualisée « COVID-19 non réanimatoire » : organisation et résultats

Introduction

La pandémie à COVID-19 a touché presque tous les pays du monde, dont la France. Tous les départements français ont ouvert des unités dédiées pour la gestion de la phase aiguë de l’épidémie. Au sein de notre site, notre structure a été la seule à accueillir une unité pour gérer des patients confirmés COVID-19 positifs. En l’absence de soins intensifs sur place, ces patients étaient triés au SAU et ne venaient que les patients sans indication de soins intensifs en raison du bénéfice/risque attendu (âge, comorbidités). Pour activer cette unité, une équipe mutualisée a été mise en place que ce soit au niveau du personnel médical PM (seniors, internes, externes) que personnel non médical (PNM) détachés des services de médecine interne, pédiatrie, médecine du sport, consultation, endocrinologie, hépatologie de notre CHU. Un support psychologique a été proposé aux soignants et aux familles par une équipe mobile de psychiatrie. L’activité quotidienne a été réorganisée après la création de plusieurs binômes junior-senior, en service de 8 h à 19 h, 7 j/7. La continuité des soins a été assurée chaque jour par 3 staffs pour permettre respectivement les transmissions de la nuit entre PM et PNM ; l’état des lieux après la visite du matin ; les projets pour le lendemain. Tous les patients ont été réévalués chaque jour et réorientés selon une échelle de gravité structurée par 5 codes-couleurs. Les externes ont eu pour mission de contacter les familles du fait de la limitation des visites, ainsi que les médecins traitants afin d’améliorer la gestion après le RAD. Les patients ont été traités par oxygénothérapie et protocoles d’antibiothérapie et morphine.

Matériels et méthodes

Analyse descriptive des données personnelles, de la mortalité brute et des issues de l’hospitalisation.

Résultats

Entre le 13 mars et le 19 mai, 147 patients, 56 % d’eux de sexe féminin, ont été hospitalisés dans cette unité d’une capacité maximale de 25 lits. L’âge moyen était de 69 ans [18 ; 97]. La durée moyenne du séjour a été de 5 jours [0 : 29]. La mortalité totale était du 20,4 %, dont 51 % des patients sont rentrés vers leur domicile ou vers des EHPAD. Ensuite, 14,3 % des patients ont été transférés vers un autre service de médecine aiguë, et 12,2 % des patients a poursuit les soins dans un SSR.

Conclusion

L’organisation de ce service montre comme une équipe de PM et PNM avec fonds de travail différentes peut être rapidement mise en place pendant une période de crise. La présence d’un service dédié à la gestion des cas de COVID-19 sans indication à soins intensifs peut soulager des autres services au sein d‘un groupe hospitalier qui travaille en coordination. La mortalité des patients hospitalisés dans ce service reste baisse considérant les comorbidités et l’âge des patients. La durée courte du séjour a permis d’accueillir un grand nombre de patients et de garantir de places en médecine aiguë standard au sein du GH.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Antenatal testing for anaemia, HIV and syphilis in Indonesia - a health systems analysis of low coverage

BACKGROUND

Adverse pregnancy outcomes can be prevented through the early detection and treatment of anaemia, HIV and syphilis during the antenatal period. Rates of testing for anaemia, HIV and syphilis among women attending antenatal services in Indonesia are low, despite its mandate in national guidelines and international policy.

METHODS

Midwife-held antenatal care records for 2015 from 8 villages in 2 sub-districts within Cianjur district were reviewed, alongside the available sub-district Puskesmas (Community Health Centre) maternity and laboratory records. We conducted four focus group discussions with kaders (community health workers) (n = 16) and midwives (n = 9), and 13 semi-structured interviews with laboratory and counselling, public sector maternity and HIV management and relevant non-governmental organisation staff. Participants were recruited from village, sub-district, district and national level as relevant to role.

RESULTS

We were unable to find a single recorded result of antenatal testing for HIV, syphilis or anaemia in the village (566 women) or Puskesmas records (2816 women) for 2015. Laboratory records did not specifically identify antenatal women. Participants described conducting and reporting testing in a largely ad hoc manner; relying on referral to health facilities based on clinical suspicion or separate non-maternity voluntary counselling and testing programs. Participants recognized significant systematic challenges with key differences between the more acceptable (and reportedly more often implemented) haemoglobin testing and the less acceptable (and barely implemented) HIV and syphilis testing. However, a clear need for leadership and accountability emerged as an important factor for prioritizing antenatal testing and addressing these testing gaps.

CONCLUSIONS

Practical solutions such as revised registers, availability of point-of-care tests and capacity building of field staff will therefore need to be accompanied by both funding and political will to coordinate, prioritize and be accountable for testing in pregnancy.

Variation in esophageal anastomosis technique-the role of collaborative learning

Centralization of care has improved outcomes in esophagogastric (EG) cancer surgery. However, specialist surgical centers often work within clinical silos, with little transfer of knowledge and experience. Although variation exists in multiple dimensions of perioperative care, the differences in operative technique are rarely studied. An esophageal anastomosis workshop was held to identify areas of common and differing practice within the operative technique. Surgeons showed videos of their anastomosis technique by open and minimally invasive surgery. Each video was followed by a discussion. Surgeons from 10 different EG cancer centers attended. Eight key technical differences and learning points were identified and discussed: the optimum diameter of the gastric conduit; avoiding ischemia in the gastric conduit; minimizing esophageal trauma; the use of an esophageal mucosal collar; omental wrapping; intraoperative leak testing; ideal diameter of the circular stapler and the growing use of linear stapled anastomoses. The workshop received positive feedback from participants and on 2 years follow-up, 40% stated that they believed that the learning of tips and techniques during the workshop has contributed to lowering their anastomotic leak rate. Many differences exist in surgical technique. The reasons for, and crucially the significance of, these differences must be discussed and examined. Workshops provide a forum for peer-to-peer collaborative learning to reflect on one's own practice and improve surgical technique. These changes can, in turn, generate incremental improvements in patient care and postoperative outcomes.

Hypoganglionosis in the gastric antrum causes delayed gastric emptying

BACKGROUND

Enteric nervous system (ENS) abnormalities have been implicated in delayed gastric emptying but studies exploring potential treatment options are limited by the lack of an experimental animal model. We examined the ENS abnormalities in the mouse stomach associated with aging, developed a novel model of gastroparesis, and established a new approach to measure gastric emptying.

METHODS

A modified gastric emptying assay was developed, validated in nNOS ^-/- mice, and tested in mice at multiple ages. Age-related changes in ENS structure were analyzed by immunohistochemistry. Gastric aganglionosis was generated in Wnt1-iDTR mice using focal administration of diphtheria toxin (DT) into the anterior antral wall.

KEY RESULTS

Older mice (>5 months) exhibit hypoganglionosis in the gastric antrum and a decreased proportion of nNOS neurons as compared to younger mice (age 5-7 weeks). This was associated with a significant age-dependent decrease in liquid and solid gastric emptying. A novel model of gastric antrum hypoganglionosis was established using neural crest-specific expression of diphtheria toxin receptor. In this model, a significant reduction in liquid and solid gastric emptying is observed.

CONCLUSIONS & INFERENCES

Older mice exhibit delayed gastric emptying associated with hypoganglionosis and a reduction in nNOS-expressing neurons in the antrum. The causal relationship between antral hypoganglionosis and delayed gastric emptying was verified using a novel experimental model of ENS ablation. This study provides new information regarding the pathogenesis of delayed gastric emptying and provides a robust model system to study this disease and develop novel treatments.

Barn-Raising on the Digital Frontier: The L.A.U.N.C.H. Collaborative

A meta-analysis of oncology papers from around the world revealed that cancer patients who lived more than 50 miles away from hospital centers routinely presented with more advanced stages of disease at diagnosis, exhibited lower adherence to prescribed treatments, presented with poorer diagnoses, and reported a lower quality of life than patients who lived nearer to care facilities. Connected health approaches-or the use of broadband and telecommunications technologies to evaluate, diagnose, and monitor patients beyond the clinic-are becoming an indispensable tool in medicine to overcome the obstacle of distance.

Enteric neuronal cell therapy reverses architectural changes in a novel diphtheria toxin-mediated model of colonic aganglionosis

Hirschsprung disease (HSCR) is characterized by absence of the enteric nervous system (ENS) in the distal bowel. Despite removal of the aganglionic segment, gastrointestinal (GI) problems persist. Cell therapy offers potential treatment but use of genetic models is limited by their poor survival. We have developed a novel model of aganglionosis in which enteric neural crest-derived cells (ENCDCs) express diphtheria toxin (DT) receptor. Local DT injection into the colon wall results in focal, specific, and sustained ENS ablation without altering GI transit or colonic contractility, allowing improved survival over other aganglionosis models. Focal ENS ablation leads to increased smooth muscle and mucosal thickness, and localized inflammation. Transplantation of ENCDCs into this region leads to engraftment, migration, and differentiation of enteric neurons and glial cells, with restoration of normal architecture of the colonic epithelium and muscle, reduction in inflammation, and improved survival.

P3346Validation of obesity coding among newly-treated nonvalvular atrial fibrillation patients using an integrated electronic medical record and claims database

Background

Obesity is prevalent among patients with non-valvular atrial fibrillation (NVAF). Administrative claims databases offer the opportunity to evaluate obesity and morbid obesity in this patient population. However, there is limited information about the use and accuracy of diagnosis codes in claims data to identify obesity and morbid obesity among patients with NVAF.

Purpose

To evaluate the use and accuracy of diagnosis codes in claims data for identifying obesity and morbid obesity among newly-treated NVAF patients using a large geographically-diverse US database.

Methods

This retrospective study used Optum's de-identified integrated electronic medical record (EMR) and claims database (1/1/2013–3/31/2018). Adult (≥18 years) patients with ≥1 claim for an oral anticoagulant (OAC) from 1/1/2014–9/30/2017 were identified (treatment date as index date). Patients were required to have ≥1 atrial fibrillation diagnosis prior to the index date and were excluded if they had evidence of OAC use or valvular disease during the 12 months prior to the index date. Patients were required to have ≥12 months of continuous enrollment prior to and ≥6 months after the index date as well as ≥1 BMI measurement in the EMR data during the 6 months before or after the index date. Based on the World Health Organization's definition, patients were classified as obese if their BMI was ≥30 kg/m2 and morbidly obese if their BMI was ≥40 kg/m2. Sensitivity, specificity, and positive predictive value (PPV) were calculated to assess the accuracy of diagnosis codes for obesity (ICD-9 diagnosis codes: 278.00, 278.01, 278.03, V85.30-V85.39, V85.41-V85.45; ICD-10 diagnosis codes: E66.01, E66.09, E66.2, E66.8, E66.9, Z68.30-Z68.39, Z68.41-Z68.45) and morbid obesity (ICD-9 diagnosis codes: 278.01, V85.41-V85.45; ICD-10 diagnosis codes: E66.01, E66.2, Z68.41-Z68.45) commonly used in claims database research.

Results

There were 7,501 patients included in the newly-treated NVAF cohort (mean [±SD] age=72.4 [±10.7] years, 55% male, 90% white, and mean [±SD] Quan-Charlson Comorbidity Index =2.10 [±2.08]). Forty-six percent of these patients had BMI≥30 kg/m2, of whom about one-quarter (11% of the overall sample) had a BMI≥40 kg/m2. In contrast, 25% and 10% of patients had a diagnosis code for obesity or morbid obesity, respectively. For obesity diagnosis codes, sensitivity, specificity, and PPV were 49% (95% CI: 47%-50%), 95% (95%-96%), and 90% (88%-91%), respectively. For morbid obesity diagnosis codes, sensitivity, specificity, and PPV were 63% (59%-63%), 96% (96%-97%) and 68% (64%-71%), respectively.

Conclusion

Among newly-treated NVAF patients, obesity diagnosis codes in the claims database had high PPV, high specificity, and modest sensitivity. Morbid obesity diagnosis codes also had high specificity but modest PPV and sensitivity. These findings have implications for both case selection and control for obesity as a confounder in observational studies using a claims database.

Acknowledgement/Funding

The funding for the research project was provided by Pfizer Inc.

Evidence-Based Guideline on Laparoscopy in Pregnancy: Commissioned by the British Society for Gynaecological Endoscopy (BSGE) Endorsed by the Royal College of Obstetricians & Gynaecologists (RCOG)

Laparoscopy is widely utilised to diagnose and treat acute and chronic, gynaecological and general surgical conditions. It has only been in recent years that laparoscopy has become an acceptable surgical alternative to open surgery in pregnancy. To date there is little clinical guidance pertaining to laparoscopic surgery in pregnancy. This is why the BSGE commissioned this guideline. MEDLINE, EMBASE, CINAHL and the Cochrane library were searched up to February 2017 and evidence was collated and graded following the NICE-approved process. The conditions included in this guideline are laparoscopic management of acute appendicitis, acute gall bladder disease and symptomatic benign adnexal tumours in pregnancy. The intended audience for this guideline is obstetricians and gynaecologists in secondary and tertiary care, general surgeons and anaesthetists. However, only laparoscopists who have adequate laparoscopic skills and who perform complex laparoscopic surgery regularly should undertake laparoscopy in pregnant women, since much of the evidence stems from specialised centres.

Evaluating societal outcomes of orthognathic surgery: an innovative application of the Social Return on Investment methodology to patients after orthognathic treatment

Outcomes after orthognathic treatment are complex, and include improvements to mental and physical health, and psychosocial adjustments. The Social Return on Investment (SROI), a framework that is recognised by the government, explores the wider social value of interventions, but has not yet, to our knowledge, been used to measure the value of surgical procedures. To test its feasibility in a surgical setting and to begin to understand the wider nature of the changes experienced by patients after orthognathic surgery, we designed a pilot study that focused on the first two stages of the six-stage model. We collected data from 16 participants about their perceptions and experiences of the short, medium, and longer term outcomes of their treatment during two qualitative storyboard workshops. A grounded theory-SROI method was used to explore their experiences through a process of constant comparison by which data were analysed for concepts and organised into distinct themes. This produced a theory of change that clearly expressed the short to medium-term and longer term outcomes of orthognathic treatment, and provided an initial framework for the approach. The theory captured several outcomes and showed that the framework can be used effectively to investigate the wider psychosocial changes after orthognathic treatment. It therefore provides a basis on which to develop potential indicators for the assessment and valuation of these outcomes over time. The application of these findings to the selection of patients, engagement, and postoperative care, is briefly discussed.