Neurogenic thoracic outlet syndrome: When to consider the diagnosis and current management options.

BACKGROUND: Thoracic outlet syndrome (TOS) refers to a group of compressive disorders that occur in the thoracic outlet and can affect the brachial plexus, subclavian artery and vein. Neurogenic TOS (nTOS) is the most common form of TOS, accounting for approximately 97% of cases. nTOS and its resulting compressive brachial plexopathy can lead to potentially disabling symptoms and reduced quality of life. OBJECTIVE: This article reviews the current literature on nTOS and summarises the pathophysiology, diagnostic pathways and the management options for nTOS. DISCUSSION: nTOS is an uncommon but disabling disorder with no single 'rule-in' test, often resulting in diagnostic delays and late referral. Initial management is non-operative with targeted physiotherapy. If this is unsuccessful, symptoms can be relieved with scalene botulinum toxin injections and surgical intervention.

MRI-based mechanical analysis of carotid atherosclerotic plaque using a material-property-mapping approach: A material-property-mapping method for plaque stress analysis.

BACKGROUND AND OBJECTIVE: Atherosclerosis is a major underlying cause of cardiovascular conditions. In order to understand the biomechanics involved in the generation and rupture of atherosclerotic plaques, numerical analysis methods have been widely used. However, several factors limit the practical use of this information in a clinical setting. One of the key challenges in finite element analysis (FEA) is the reconstruction of the structure and the generation of a mesh. The complexity of the shapes associated with carotid plaques, including multiple components, makes the generation of meshes for biomechanical computation a difficult and in some cases, an impossible task. To address these challenges, in this study, we propose a novel material-property-mapping method for carotid atherosclerotic plaque stress analysis that aims to simplify the process. METHODS: The different carotid plaque components were identified and segmented using magnetic resonance imaging (MRI). For the mapping method, this information was used in conjunction with an in-house code, which provided the coordinates for each pixel/voxel and tissue type within a predetermined region of interest. These coordinates were utilized to assign specific material properties to each element in the volume mesh which provides a region of transition. The proposed method was subsequently compared to the traditional method, which involves creating a composed mesh for the arterial wall and plaque components, based on its location and size. RESULTS: The comparison between the proposed material-property-mapping method and the traditional method was performed in 2D, 3D structural-only, and fluid-structure interaction (FSI) simulations in terms of stress, wall shear stress (WSS), time-averaged WSS (TAWSS), and oscillatory shear index (OSI). The stress contours from both methods were found to be similar, although the proposed method tended to produce lower local maximum stress values. The WSS contours were also in agreement between the two methods. The velocity contours generated by the proposed method were verified against phase-contrast magnetic resonance imaging (MRI) measurements, for a higher level of confidence. CONCLUSION: This study shows that a material-property-mapping method can effectively be used for analyzing the biomechanics of carotid plaques in a patient-specific manner. This approach has the potential to streamline the process of creating volume meshes for complex biological structures, such as carotid plaques, and to provide a more efficient and less labor-intensive method.

Distalization of the anastomosis: an effective treatment for dialysis access-associated steal syndrome.

Steal syndrome after arteriovenous fistula formation for dialysis access can cause ischemic pain and tissue loss. This is an indication for surgical revision, usually either banding (or ligation) or the distal revascularisation and interval ligation procedure. However, banding is inexact, and distal revascularisation and interval ligation can further compromise the arterial supply to the arm. We report three cases in which an alternative approach of moving the arteriovenous anastomosis distally was used, thereby protecting arterial inflow to the hand. In all three cases, the steal resolved and the fistula remained patent.

A retrospective analysis of the investigative practices of acute limb ischaemia presenting with an unknown aetiology.

BACKGROUND: Acute limb ischaemia (ALI) is a limb and life-threatening condition with significant morbidity. There are currently no consensus recommendations for the investigative practices to determine the aetiology of ALI presenting without a known aetiology. We undertook a detailed analysis of all investigations performed to identify an underlying precipitant in those with unexplained ALI and formulated a suggested diagnostic algorithm for the evaluation of unexplained ALI. METHODS: ALI cases presenting to a tertiary referral centre over a 3-year period were reviewed, and known aetiologies, and investigations undertaken to determine the underlying aetiology of unexplained ALI were obtained. RESULTS: Unexplained ALI was found in 27 of 222 patients (12%), of which 21 (78%) had a cause for ALI established after further investigations. Six patients had no cause identified despite extensive work-up. Most patients with unexplained ALI had a cardioembolic source identified as the underlying cause (62%), and this included atrial fibrillation, infective endocarditis, cardiac myxoma and intra-cardiac thrombus. Other causes of unexplained ALI were detected by computed tomography (CT) imaging and included newly diagnosed significant atherosclerotic disease (19%), embolism from isolated proximal large vessel thrombus (10%) and metastatic malignancy (10%). There were no cases attributed to inherited thrombophilias, myeloproliferative neoplasms or anti-phospholipid syndrome. CONCLUSION: Among patients with unexplained ALI, the majority had a cardioembolic source highlighting the importance of comprehensive cardiac investigations. A subset of patients had alternative causes identified on CT imaging. These data support the use of a collaborative and integrative diagnostic algorithm in the evaluation of unexplained ALI.

Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

The cardiovascular and prognostic significance of the infrarenal aortic diameter.

The normal aortic diameter in adults usually ranges from 16 to 18 mm in women and 19 to 21 mm in men. Individuals with diameters outside this range seem to be at increased risk of other cardiovascular disease. There is a graded association between increasing aortic diameter and both cardiovascular mortality and peripheral arterial disease. The magnitude of increased risk of cardiovascular death seems to be about 4% to 6% per mm increase over a diameter of about 23 mm. To a lesser extent, these outcomes are also increased in individuals with aortic diameters below the normal range. While the threshold of 3 cm is useful in the diagnosis of abdominal aortic aneurysm (AAA), it is arbitrary in terms of the vascular biology and pathophysiology of the abdominal aorta. This review examines the risk factors for aortic enlargement and the cardiovascular implications of this enlargement in patients with and without AAAs. The mechanisms underlying the association between aortic diameter and cardiovascular risk and the relevance to screening are also discussed.

Carotid artery stenosis: An approach to its diagnosis and management.

BACKGROUND: Carotid artery stenosis (CAS) is one of the major causes of acute ischaemic stroke, accounting for approximately 20% of cases. It is not always symptomatic; however, when it is, the neurological vascular territory it commonly affects is the anterior circulation of the brain, causing symptoms such as hemiplegia, dysphasia or vision loss. OBJECTIVE: The aim of this article is to review the current literature on CAS, summarise the main updates and evidence base for surgical management, and discuss when vascular surgical input may be beneficial. DISCUSSION: CAS can be classified as symptomatic or asymptomatic disease. Carotid endarterectomy remains important in the treatment of symptomatic disease because of a strong evidence base for its benefit in the overall reduction of recurrent stroke risk. The benefit of surgery is less clear for asymptomatic disease. Commencement of best medical therapy as well as cardiovascular risk factor modification is a mainstay of treatment for both groups of patients.

Management of primary mycotic aneurysms and prosthetic graft infections: an 8-year experience with in-situ cryopreserved allograft reconstruction.

BACKGROUND: Primary mycotic aneurysms and prosthetic graft infections are traditionally managed by resection of infected vascular tissue and revascularisation with an extra-anatomical bypass. Long-term patency for this method has been reported to be poor with associated high reinfection and limb amputation rates. The aim of this study was to analyse the outcomes of those patients in our department between 2010 and 2018 whom had revascularisation with in-situ arterial reconstruction using cryopreserved allograft as a conduit. METHODS: The data were retrospectively reviewed and 13 patients were identified. There were five patients with primary mycotic aneurysms and eight patients with prosthetic graft infections, three of which were complicated by aortoenteric fistulae (AEF). RESULTS: There were three peri-operative mortalities (23%) with all three mortalities related to graft re-infection and post-implantation haemorrhage; two of these from uncontrolled bile leaks related to the original AEF with persistent graft contamination. The 10 surviving patients were followed up for a mean duration of 15.8 months with an overall primary graft patency of 89% and no incidence of graft re-infection or aneurysmal degeneration. CONCLUSION: Patients that survived the peri-operative period demonstrated acceptable medium-term allograft durability, with the most favourable outcomes observed in those patients who had arterial infections uncomplicated by AEF. The main barrier to more wide-spread use in our state remains inadequate supply of banked cryopreserved tissue.

The impact of a supportive leadership program in a policing organisation from the participants' perspective.

AIM: The aim of this study is to explore the implementation of an organisational level intervention, focussing on Supportive Leadership (SL), in an Australian police organisation from the perspective of supervisors and managers. DESIGN: The impact of the intervention was explored using a qualitative methodology using semi-structured telephone interviews with 44 participants who had attended the Supportive Leadership Workshop, designed to improve awareness of good management practices. Data was subjected to thematic analysis using a social constructivist theoretical orientation. FINDINGS: Findings showed that SL as a concept was generally accepted by a majority of participants and that they had integrated a number of SL strategies into their work practices. The participants also identified the importance of senior personnel role-modelling SL and the negative impact of non-role modelling. RESEARCH LIMITATIONS AND IMPLICATIONS: The major limitation of the study was the non-random sample of voluntary participants. However, the nature of conducting applied studies in police organisations is inherently difficult due to confidentiality and their paramilitary nature. This study highlights the need for future studies in police leadership and occupational stress that directly explore issues from the perspective of the supervisors and managers. PRACTICAL IMPLICATIONS: Interventions such as SL need support and role modelling from senior management to enhance their credibility. ORIGINAL VALUE: This paper reports on an applied intervention that received major support and funding within a police organisation. It is of value to other organizations considering similar interventions because it highlights issues that could be addressed to further enhance the program.

Association between osteopontin and human abdominal aortic aneurysm.

OBJECTIVES: In vitro and animal studies have implicated osteopontin (OPN) in the pathogenesis of aortic aneurysm. The relationship between serum concentration of OPN and variants of the OPN gene with human abdominal aortic aneurysm (AAA) was investigated. METHODS AND RESULTS: OPN genotypes were examined in 4227 subjects in which aortic diameter and clinical risk factors were measured. Serum OPN was measured by ELISA in two cohorts of 665 subjects. The concentration of serum OPN was independently associated with the presence of AAA. Odds ratios (and 95% confidence intervals) for upper compared with lower OPN tertiles in predicting presence of AAA were 2.23 (1.29 to 3.85, P=0.004) for the population cohort and 4.08 (1.67 to 10.00, P=0.002) for the referral cohort after adjusting for other risk factors. In 198 patients with complete follow-up of aortic diameter at 3 years, initial serum OPN predicted AAA growth after adjustment for other risk factors (standardized coefficient 0.24, P=0.001). The concentration of OPN in the aortic wall was greater in patients with small AAAs (30 to 50 mm) than those with aortic occlusive disease alone. There was no association between five single nucleotide polymorphisms or haplotypes of the OPN gene and aortic diameter or AAA expansion. CONCLUSIONS: Serum and tissue concentrations of OPN are associated with human AAA. We found no relationship between variation of the OPN gene and AAA. OPN may be a useful biomarker for AAA presence and growth.

Abdominal aortic aneurysm: pathogenesis and implications for management.

Abdominal aortic aneurysm (AAA) affects approximately 5% of elderly men and is responsible for a significant number of deaths in Western Countries. At present surgery by open or endovascular means is the only widely used therapy for this condition. In this review we examine the risk factors, serum, and genetic associations of AAA. Epidemiology studies suggest that smoking cessation and control of cholesterol and blood pressure should reduce the number of patients developing AAA. Natural history studies suggest that smoking cessation should reduce the rate of progression of AAA. Clear level 1 evidence for drug treatments of AAA are presently lacking; however, animal and human in vitro studies suggest that medication targeted at reducing inflammation and proteolysis are most likely to be beneficial, with limited data to support the use of statins, Angiotensin II inhibitors, and macrolides. Work has commenced in understanding which patients, identified by clinical, serum, and genotype, are more at risk of AAA progression and thus should be selected out for aggressive treatment. Well designed large multicenter randomized controlled trials are required to examine the medical treatment of AAA.

Reduced expansion rate of abdominal aortic aneurysms in patients with diabetes may be related to aberrant monocyte-matrix interactions.

AIMS: Diabetes increases the risk of atherothrombosis, but reduces the risk of abdominal aortic aneurysm (AAA). The reason for this difference is unknown. We examined the role of diabetes and glycation on AAA expansion and extracellular matrix-monocyte interactions. METHODS AND RESULTS: We followed 198 patients (20 with diabetes) who had 30-45 mm AAAs with yearly aortic ultrasound for 3 years. Diabetes was independently associated with reduced AAA growth (beta = -0.17, P = 0.01; OR for expansion above median 0.18, 95% confidence interval 0.06-0.57). In vitro incubation of resting human monocytes with glycated bovine serum albumin or monomeric type I collagen increased matrix metalloproteinase (MMP) secretion. In contrast, exposure of activated monocytes to glycated type I collagen lattices induced a marked reduction in MMP and interleukin-6 secretion. This de-activating effect was also demonstrated in cross-linked non-glycated collagen lattices, healthy decellularized aortic media, and decellularized aortic media from diabetes patients with atherosclerosis. In contrast, decellularized aortic media from patients with atherosclerosis, but no diabetes, induced increased MMP secretion. CONCLUSION: These findings confirm that the progression of AAA is slower in patients with diabetes and suggest a mechanism by which the aortic media may be protected from degradation in these individuals.

Leaving high school: the influence and consequences for psychological well-being and career-related confidence.

This paper examines the well-being and career decision-making self-efficacy (CDMSE) of adolescents before and after leaving school, and tests for the changes in these variables as a result of leaving school. While at high school, 309 students were assessed on levels of school achievement, well-being (psychological distress, self-esteem, life satisfaction) and CDMSE. Nine months after leaving school, 168 of these students completed the above surveys and measures of their access to the latent (e.g. social contact, time structure) and manifest (i.e. financial) benefits of employment, and work commitment. At T2, 21% were full-time students, 35% were full-time students who were also working part-time, 22% were employed in full-time jobs, and 21% were in the labour market but not employed full-time. These groupings were differentiated at T2 on aspects of well-being, self-efficacy, and access to the latent and manifest benefits of work, and at T1 on aspects of well-being and confidence. Leaving school improved well-being and confidence for some. One group was disadvantaged by having poorer well-being while at school, which predisposed them to disadvantage in the labour market. Results are discussed in relation to models of well-being and drift/social causation.