Radiologist variability in assessing the position of the cavoatrial junction on chest radiographs

Objectives: To assess the variability in identifying the cavo-atrial junction (CAJ) on chest x-rays amongst radiologists. Methods: Twenty-three radiologists (13 consultants and 10 trainees) assessed 25 postero-anterior erect chest x-rays (including eight duplicates) and marked the positions of the CAJ. Differences in the CAJ position both within and between observers were evaluated and reported as limits of agreement, repeatability coefficients, intra-class correlation coefficients and displayed graphically with Bland- Altman plots. Results: The mean difference for within observer assessments was -0.2 cm (95% limits of agreement, -1.5 to +1.1 cm) and between observers was -0.3 cm (95% limits of agreement, -2.5 to +1.8 cm). Intra-observer repeatability coefficients (RC) were marginally lower for consultants when compared to trainees (1.1 versus 1.5). RCs between observers were comparable (2.1 versus 2.2) for for consultants and trainees, respectively. Conclusions: This study detected a large inter-observer variability of the CAJ position (up to 4.3 cm). This is a significant finding considering that the length of the SVC is reported to be approximately 7cm. We conclude that there is poor consensus regarding the CAJ position amongst radiologists. Advances in knowledge: No comparisons exist between radiologists in determining CAJ position from chest X-rays. This report provides evidence of the large observer variability amongst radiologists and adds to the discussion regarding the use of chest X-rays in validating catheter tip location systems

Observations on surveillance imaging after endovascular sealing of abdominal aortic aneurysms with the Nellix system

Purpose: To describe and interpret the findings of computed tomography images acquired before and after endovascular aneurysm sealing (EVAS) with the Nellix endoprosthesis and consider the potential implications of these findings on EVAS planning and performance. Methods: A retrospective review was performed of perioperative imaging from 30 consecutive patients (median age 79 years; 19 men) undergoing elective EVAS at our center between December 2013 and November 2014. The images were systematically reviewed specifically looking for endobag collapse, aortic thrombus compression, and aortic wall disruption according to definitions set a priori. Results: There was no perioperative mortality or endoleak after the EVAS procedure. Endobag collapse, which could potentially result in type II endoleak if occurring near a patent side branch, was seen in the endobags of 12 patients. Aortic thrombus compression, which affects the accuracy of preoperative volume measurements in predicting the amount of polymer needed to perform EVAS, was seen in 15 patients. There was one aortic wall disruption, which could potentially result in intraoperative hemorrhage, though this did not occur in this case. Conclusion: These observations and their potential implications should help clinicians in planning and performing EVAS, as well as in interpreting postoperative imaging

Abdominal aortic aneurysms and endovascular sealing: deformation and dynamic response

Endovascular sealing is a new technique for the repair of abdominal aortic aneurysms. Commercially available in Europe since~2013, it takes a revolutionary approach to aneurysm repair through minimally invasive techniques. Although aneurysm sealing may be thought as more stable than conventional endovascular stent graft repairs, post-implantation movement of the endoprosthesis has been described, potentially leading to late complications. The paper presents for the first time a model, which explains the nature of forces, in static and dynamic regimes, acting on sealed abdominal aortic aneurysms, with references to real case studies. It is shown that elastic deformation of the aorta and of the endoprosthesis induced by static forces and vibrations during daily activities can potentially promote undesired movements of the endovascular sealing structure

Development of HomeSTEAD's physical activity and screen time physical environment inventory

BACKGROUND: The home environment has a significant influence on children's physical activity, sedentary behavior, dietary intake, and risk for obesity and chronic disease. Our understanding of the most influential factors and how they interact and impact child behavior is limited by current measurement tools, specifically the lack of a comprehensive instrument. HomeSTEAD (the Home Self-administered Tool for Environmental assessment of Activity and Diet) was designed to address this gap. This new tool contains four sections: home physical activity and media equipment inventory, family physical activity and screen time practices, home food inventory, and family food practices. This paper will describe HomeSTEAD's development and present reliability and validity evidence for the first section. METHODS: The ANGELO framework guided instrument development, and systematic literature reviews helped identify existing items or scales for possible inclusion. Refinement of items was based on expert review and cognitive interviews. Parents of children ages 3-12 years (n = 125) completed the HomeSTEAD survey on three separate occasions over 12-18 days (Time 1, 2, and 3). The Time 1 survey also collected demographic information and parent report of child behaviors. Between Time 1 and 2, staff conducted an in-home observation and measured parent and child BMI. Kappa and intra-class correlations were used to examine reliability (test-retest) and validity (criterion and construct). RESULTS: Reliability and validity was strong for most items (97% having ICC > 0.60 and 72% having r > 0.50, respectively). Items with lower reliability generally had low variation between people. Lower validity estimates (r < 0.30) were more common for items that assessed usability and accessibility, with observers generally rating usability and accessibility lower than parents. Small to moderate, but meaningful, correlations between physical environment factors and BMI, outside time, and screen time were observed (e.g., amount of child portable play equipment in good condition and easy to access was significantly associated with child BMI: r = -0.23), providing evidence of construct validity. CONCLUSIONS: The HomeSTEAD instrument represents a clear advancement in the measurement of factors in the home environment related to child weight and weight-related behaviors. HomeSTEAD, in its entirety, represents a useful tool for researchers from which they can draw particular scales of greatest interest and highest relevance to their research questions

Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR)

Background In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre. Methods A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels. Results Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7–5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush. Conclusion Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located

Intra-abdominal pectus bar migration – a rare clinical entity: case report

We present the case of a 20-year-old male who underwent successful surgical correction of pectus excavatum with the Highly Modified Ravitch Repair (HMRR). At 29 months the attempted operative removal of the Ravitch bar was unsuccessful despite the impression of adequate bar location on chest x-ray. Subsequent imaging with computed tomography was unclear in determining whether the bar was supra or infra-diaphragmatic due to the tissue distortion subsequent to initial surgery. Video assisted thoracoscopic surgery (VATS) successfully retrieved the bar and revealed that it was not in the thorax, but had migrated to the intra-abdominal bare area of the liver, with no evidence of associated diaphragmatic defect or hernia. Intra-abdominal pectus bar migration is a rare clinical entity, and safe removal can be facilitated by the use of the VATS technique

Standard of Practice for the Endovascular Treatment of Thoracic Aortic Aneurysms and Type B Dissections

Thoracic endovascular aortic repair (TEVAR) represents a minimally invasive technique alternative to conventional open surgical reconstruction for the treatment of thoracic aortic pathologies. Rapid advances in endovascular technology and procedural breakthroughs have contributed to a dramatic transformation of the entire field of thoracic aortic surgery. TEVAR procedures can be challenging and, at times, extraordinarily difficult. They require seasoned endovascular experience and refined skills. Of all endovascular procedures, meticulous assessment of anatomy and preoperative procedure planning are absolutely paramount to produce optimal outcomes. These guidelines are intended for use in quality-improvement programs that assess the standard of care expected from all physicians who perform TEVAR procedures

Direct measurement of thermal conductivity in solid iron at planetary core conditions

The conduction of heat through minerals and melts at extreme pressures and temperatures is of central importance to the evolution and dynamics of planets. In the cooling Earth’s core, the thermal conductivity of iron alloys defines the adiabatic heat flux and therefore the thermal and compositional energy available to support the production of Earth’s magnetic field via dynamo action1, 2, 3. Attempts to describe thermal transport in Earth’s core have been problematic, with predictions of high thermal conductivity4, 5, 6, 7 at odds with traditional geophysical models and direct evidence for a primordial magnetic field in the rock record8, 9, 10. Measurements of core heat transport are needed to resolve this difference. Here we present direct measurements of the thermal conductivity of solid iron at pressure and temperature conditions relevant to the cores of Mercury-sized to Earth-sized planets, using a dynamically laser-heated diamond-anvil cell11, 12. Our measurements place the thermal conductivity of Earth’s core near the low end of previous estimates, at 18–44 watts per metre per kelvin. The result is in agreement with palaeomagnetic measurements10 indicating that Earth’s geodynamo has persisted since the beginning of Earth’s history, and allows for a solid inner core as old as the dynamo

The genetic epidemiology of joint shape and the development of osteoarthritis

Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed