Contrasting Effects of Varicose Vein Surgery on Endothelial-dependent and -independent Cutaneous Vasodilation in the Perimalleolar Region

AbstractObjectivesTo evaluate the effects of varicose vein surgery on cutaneous microvascular perfusion and vasodilator responses to acetylcholine (Ach) and sodium nitroprusside (SNP) in the gaiter area of patients with great saphenous vein insufficiency.MethodsTwenty-nine patients with isolated great saphenous vein incompetence attended three study mornings (before surgery, and 6–8 weeks and 6 months after sapheno-femoral ligation+partial stripping) during which cutaneous microvascular responses were measured in the supine and standing positions using laser Doppler fluximetry (LDF) combined with incremental-dose iontophoretic administration of endothelial-dependent (Ach) and -independent (SNP) vasodilators.ResultsVaricose vein surgery had no significant effect on baseline cutaneous perfusion or the microvascular response to Ach: e.g. peak vasodilator responses to the 1000μC stimulus were mean 58 SEM 7, 64 SEM 6 and 65 SEM 7PU on the pre-operative, 6–8 weeks and 6 months assessments. In contrast, the corresponding responses to SNP were significantly increased following surgery: e.g. at 2000μC, mean 63 SEM 9, 142 SEM 4 and 157 SEM 9PU (p<0.0001) in the upright position.ConclusionsSapheno-femoral ligation and partial stripping in patients with great saphenous vein insufficiency improves endothelial-independent cutaneous vasodilator function at the gaiter area, which may at least partly explain the benefits of surgery in reducing the risk of venous ulceration

Tool path design system to enhance accuracy during double sided incremental forming: An analytical model to predict compensations for small/large components

Double sided incremental forming (DSIF) has potential to form complex three-dimensional sheet metal components without using component specific tooling. Forming tool deflection and sheet spring-back are significant factors contributing to the geometrical inaccuracy of DSIF components. Numerical prediction and experimental measurement of sheet spring-back is time consuming. In addition, available analytical methods to predict and compensate sheet spring-back uses theory of small deflections by neglecting the membrane effects. With increase in sheet deflection beyond its thickness, membrane forces experienced by the middle plane of sheet due to stretching significantly resists the applied transverse load. In the present work, combination of small deflection and membrane theories are used to predict and compensate sheet deflections, so that a single methodology can be used for small as well as large components. Proposed methodology is validated using experimental and numerical predictions and they are in very good agreement. Two geometries (axisymmetric, free form components) with different component openings are formed to validate the proposed predictive methodology. Results indicate there is significant improvement (maximum error is less than 800 μm) in accuracy of components formed using compensated tool paths developed using proposed model. In addition, support tool maintained contact with component throughout forming (maximum force on the support tool is less than 60 N). © 2020 The Society of Manufacturing Engineer

Effects of lower limb angioplasty on endothelial-dependent and -independent microvascular reactivity

Background: Percutaneous Transluminal Angioplasty (PTA) of the lower limb improves arterial flow and claudication symptoms, but the effects on cutaneous microvascular perfusion and reactivity have not been previously reported. Report: Cutaneous microvascular function in the feet was assessed in 12 patients with intermittent claudication before and after PTA using Laser Doppler Fluximetry (LDF) with transcutaneous iontophoretic administration of acetylcholine and sodium nitroprusside. Maximum vasodilator responses to both endothelial-dependent and independent vasodilators were increased following PTA. Conclusions: Large vessel intervention to improve macrovascular flow has additional benefits on the downstreamcutaneous microcirculation to improve vasodilator responsiveness. These effects may be clinically important to reduce the risk of ischaemic ulceration and tissue breakdown

Protocol on a multicentre statistical and economic modelling study of risk-based stratified and personalised screening for diabetes and its complications in India (SMART India)

INTRODUCTION: The aim of this study is to develop practical and affordable models to (a) diagnose people with diabetes and prediabetes and (b) identify those at risk of diabetes complications so that these models can be applied to the population in low-income and middle-income countries (LMIC) where laboratory tests are unaffordable. METHODS AND ANALYSIS: This statistical and economic modelling study will be done on at least 48 000 prospectively recruited participants aged 40 years or above through community screening across 20 predefined regions in India. Each participant will be tested for capillary random blood glucose (RBG) and complete a detailed health-related questionnaire. People with known diabetes and all participants with predefined levels of RBG will undergo further tests, including point-of-care (POC) glycated haemoglobin (HbA1c), POC lipid profile and POC urine test for microalbuminuria, retinal photography using non-mydriatic hand-held retinal camera, visual acuity assessment in both eyes and complete quality of life questionnaires. The primary aim of the study is to develop a model and assess its diagnostic performance to predict HbA1c diagnosed diabetes from simple tests that can be applied in resource-limited settings; secondary outcomes include RBG cut-off for definition of prediabetes, diagnostic accuracy of cost-effective risk stratification models for diabetic retinopathy and models for identifying those at risk of complications of diabetes. Diagnostic accuracy inter-tests agreement, statistical and economic modelling will be performed, accounting for clustering effects. ETHICS AND DISSEMINATION: The Indian Council of Medical Research/Health Ministry Screening Committee (HMSC/2018–0494 dated 17 December 2018 and institutional ethics committees of all the participating institutions approved the study. Results will be published in peer-reviewed journals and will be presented at national and international conferences. TRIAL REGISTRATION: ISRCTN57962668 V1.0 24/09/2018

Protocol on a multicentre statistical and economic modelling study of risk-based stratified and personalised screening for diabetes and its complications in India (SMART India)

Introduction The aim of this study is to develop practical and affordable models to (a) diagnose people with diabetes and prediabetes and (b) identify those at risk of diabetes complications so that these models can be applied to the population in low-income and middle-income countries (LMIC) where laboratory tests are unaffordable. Methods and analysis This statistical and economic modelling study will be done on at least 48 000 prospectively recruited participants aged 40 years or above through community screening across 20 predefined regions in India. Each participant will be tested for capillary random blood glucose (RBG) and complete a detailed health-related questionnaire. People with known diabetes and all participants with predefined levels of RBG will undergo further tests, including point-of-care (POC) glycated haemoglobin (HbA1c), POC lipid profile and POC urine test for microalbuminuria, retinal photography using non-mydriatic hand-held retinal camera, visual acuity assessment in both eyes and complete quality of life questionnaires. The primary aim of the study is to develop a model and assess its diagnostic performance to predict HbA1c diagnosed diabetes from simple tests that can be applied in resource-limited settings; secondary outcomes include RBG cut-off for definition of prediabetes, diagnostic accuracy of cost-effective risk stratification models for diabetic retinopathy and models for identifying those at risk of complications of diabetes. Diagnostic accuracy inter-tests agreement, statistical and economic modelling will be performed, accounting for clustering effects. Ethics and dissemination The Indian Council of Medical Research/Health Ministry Screening Committee (HMSC/2018–0494 dated 17 December 2018 and institutional ethics committees of all the participating institutions approved the study. Results will be published in peer-reviewed journals and will be presented at national and international conferences. Trial registration number ISRCTN57962668 V1.0 24/09/2018

Effects of posture and venous insufficiency on endothelial-dependent and -independent cutaneous vasodilation in the perimalleolar region

Objectives: To assess the effects of posture, endothelial function and venous insufficiency on cutaneous microvascular vasodilator function in the gaiter area, in particular defining factors which may affect microangiopathy and ulcer formation. Methods: Endothelial-dependent and –independent vasodilator responses to incremental-doses of acetylcholine (Ach) and sodium nitroprusside (SNP) were evaluated in the perimalleolar region in the supine and standing positions in middle-aged patients with isolated superficial venous insufficiency (ISVI) (n=25) and health controls (n=28) using laser Doppler fluximetry (LDF) and iontophoresis of vasodilators. Results: The venoarteriolar reflex (vasoconstriction on standing) was equally present in both groups, and reduced the vasodilator responses to SNP in the upright position (e.g for patients with ISVI, peak SNP response was 82+11 PU [standing] vs 123+15 PU [supine]). The presence of ISVI had no effect on endothelial vasodilator function in the supine position, but on standing cutaneous reactivity to Ach was significantly reduced (e.g peak Ach response 69+8 PU [ISVI] vs 109+11 PU [controls], p<0.003). Conclusions: Upright posture impairs cutaneous endothelial-dependent vasodilation in the gaiter area of patients with ISVI. This may be of clinical and prognostic utility in identifying which patients with uncomplicated ISVI are at highest risk of tissue breakdown and ulcer formation in the gaiter area

Study protocol for a real-world evaluation of an integrated child and family health hub for migrant and refugee women

Introduction Continuity of child and family healthcare is vital for optimal child health and development for developmentally vulnerable children. Migrant and refugee communities are often at-risk of poor health outcomes, facing barriers to health service attendance including cultural, language, limited health literacy, discrimination and unmet psychosocial needs. 'Integrated health-social care hubs' are physical hubs where health and social services are co-located, with shared referral pathways and care navigation. Aim Our study will evaluate the impact, implementation and cost-benefit of the First 2000 Days Care Connect (FDCC) integrated hub model for pregnant migrant and refugee women and their infants. Materials and methods This study has three components. Component 1 is a non-randomised controlled trial to compare the FDCC model of care with usual care. This trial will allocate eligible women to intervention and control groups based on their proximity to the Hub sites. Outcome measures include: the proportion of children attending child and family health (CFH) nurse services and completing their CFH checks to 12 months of age; improved surveillance of growth and development in children up to 12 months, post partum; improved breastfeeding rates; reduced emergency department presentations; and improved maternal well-being. These will be measured using linked medical record data and surveys. Component 2 will involve a mixed-method implementation evaluation to clarify how and why FDCC was implemented within the sites to inform future roll-out. Component 3 is a within-trial economic evaluation from a healthcare perspective to assess the cost-effectiveness of the Hubs relative to usual care and the implementation costs if Hubs were scaled and replicated. Ethics and dissemination Ethical approval was granted by the South Eastern Sydney Local Health District Human Research Ethics Committee in July 2021 (Project ID: 020/ETH03295). Results will be submitted for publication in peer-reviewed journals and presented at relevant conferences. Trial registration number ACTRN12621001088831