Atherosclerosis and fibrinolysis. A study in human blood vessels

Atherosclerosis is a major cause of morbidity and mortality. The fibrinolytic system may be involved with several aspects of human atherosclerotic disease by regulating cellular migration, matrix remodelling and local thrombogenicity. The aim of the present investigation was to test the hypotheses: -Local expression of fibrinolytic factors is determined by inflammatory activity.-Macrophages and fibrinolytic factors are heterogeneously distributed in human atherosclerotic vessels.-Fibrinolytic factors are altered in aneurysmatic arteries. Immunohistochemistry was used to characterise the distribution of tissue plasminogen activator (t-PA), urokinase plasminogen activator (u-PA), plasminogen activator inhibitors type 1 and 2 (PAI-1 and PAI-2), tumour necrosis factor alpha (TNF), tissue factor (TF) and macrophages in vascular sections from patients with peripheral atherosclerotic disease. Co-localisation of fibrinolytic factors with macrophages was calculated using computer assisted image analysis of circumferential serial sections. Heterogeneity was evaluated by calculating the representativity of random samples concerning the expression of antigens as a function of sample size. Tissue extraction and immunosorbant assay was used to compare antigen and activity levels of fibrinolytic factors in aneurysmatic versus normal aortic tissue. The expression of fibrinolytic factors, especially u-PA and PAI-2, was different in atherosclerotic vessels compared to healthy controls and clearly related to the presence of macrophages. u-PA co-localised with an activated subpopulation of macrophages. Macrophages, fibrinolytic factors, TNF and TF were heterogeneously distributed in atherosclerotic vessels and the representativity of small vascular samples was poor. u-PA antigen concentration was increased and t-PA activity was decreased in aneurysmatic aortas. The results of the present study indicate that inflammatory reactions in human atherosclerotic vessels may be modulated by the fibrinolytic system, in particular by u-PA and PAI-2. Inflammatory activation and proteolytic activation may be interrelated via the u-PA-plasmin pathway. Atherosclerotic vessels are heterogeneous with respect to various important factors and results based on small vascular samples should be carefully evaluated. Furthermore, the value of small vascular samples in a clinical situation is likely to be low. Increased u-PA concentration in aortic aneurysms may promote proteolytic degradation of the vessel wall and decreased t-PA activity may contribute to mural thrombosis in the aneurysmal sac

Aligning Video-And Structured Data for Imaging Optimisation

Imaging optimisation can benefit from combining structured data with qualitative data in the form of audio and video recordings. Since video is complex to work with, there is a need to find a workable solution that minimises the additional time investment. The purpose of the paper is to outline a general workflow that can begin to address this issue. What is described is a data management process comprising the three steps of collection, mining and contextualisation. This process offers a way to work systematically and at a large scale without succumbing to the context loss of statistical methods. The proposed workflow effectively combines the video and structured data to enable a new level of insights in the optimisation process

Is EVAR a durable solution: indications for re-interventions

Indications for re-interventions after endovascular aneurysm repair (EVAR), as well as their occurrence in number and time, are important to establish in order to optimize patient selection, post-procedure surveillance and also to guide improvements in endograft designs. The aim of this report was to present an overview of current data on re-interventions after elective EVAR. Qualitative review of studies reporting on re-interventions after elective EVAR, identified by a systematic literature search in MEDLINE, EMBASE and the Cochrane Library for publications from 2010 to 13th of November 2017. Twenty-three studies reporting on 83,307 patients met the inclusion criteria. Index procedures were performed between 1996-2014. There was wide heterogeneity in reporting standards. Type I endoleaks were reported in 0.6%-13% and type III endoleaks in 0.9%-2.1% with a significant improvement for newer devices. Migration rates varied between 0%-4%. Endoleak type II was the most common indication for re-intervention ranging from 14%-25.3% although the majority resolved without intervention. Rupture rates ranged from 0%-5.4% and carried a high mortality (60%-67%). Ruptures occurred at any time after the index procedure. Limb ischemia rates were reported at 0.4%-11.9% with re-intervention rates between 0.06%-11.9%. Wound related complications and related re-interventions were the indication in 0.5%-14% and 0.3%-6.5%, respectively. Endograft infection carried a high risk of mortality and was described in 0.3%-3.6%, often related to graft-enteric fistula and the majority had an open explantation of the endograft. This review showed that the rates of complications and techniques for re-intervention developed over time with a tendency towards better outcomes considering the aneurysm related indications. Significant factors that led to subsequent secondary interventions were migration, rupture, infections and type I and II endoleaks. Patients treated with earlier generation endografts are still alive and need continued surveillance to detect these severe complications before they lead to ruptur

Results After Open and Endovascular Repair of Popliteal Aneurysm : A Matched Comparison Within a Population Based Cohort

Objective To identify factors affecting the outcome after open surgical (OSR) and endovascular (ER) repair of popliteal artery aneurysm (PA) in comparable cohorts. Methods A matched comparison in a national, population based cohort of 592 legs treated for PA (2008 – 2012), with long term follow up. Registry data from 899 PA patients treated in 2014 – 2018 were analysed for time trends. The 77 legs treated by ER were matched, by indication, with 154 legs treated with OSR. Medical records and imaging were collected. Analysed risk factors were anatomy, comorbidities, and medication. Elongation and angulations were examined in a core lab. The main outcome was occlusion. Results Patients in the ER group were older (73 vs. 68 years, p = .001), had more lung disease (p = .012), and were treated with dual antiplatelet therapy or anticoagulants more often (p &lt; .001). The hazard ratio (HR with 95% confidence intervals) for occlusion was 2.69 (1.60 – 4.55, p &lt; .001) for ER, but 3.03 (1.26 – 7.27, p = .013) for poor outflow. For permanent occlusion, the HR after ER was 2.47 (1.35 – 4.50, p = .003), but 4.68 (1.89 – 11.62, p &lt; .001) for poor outflow. In the ER subgroup, occlusion was more common after acute ischaemia (HR 2.94 [1.45 – 5.97], p = .003; and poor outflow HR 14.39 [3.46 – 59.92], p &lt; .001). Larger stent graft diameter reduced the risk (HR 0.71 [0.54 – 0.93], p = .014). In Cox regression analysis adjusted for indication and stent graft diameter, elongation increased the risk (HR 1.020 per degree [1.002 – 1.033], p = .030). PAs treated for acute ischaemia had a median stent graft diameter of 6.5 mm, with those for elective procedures being 8 mm (p &lt; .001). Indications and outcomes were similar during both time periods (2008 – 2012 and 2014 – 2018). Conclusion In comparable groups, ER had a 2.7 fold increased risk of any occlusion, and 2.4 fold increased risk of permanent occlusion, despite more aggressive medical therapy. Risk factors associated with occlusion in ER were poor outflow, smaller stent graft diameter, acute ischaemia, and angulation/elongation. An association between indication, acute ischaemia, and small stent graft diameter was identified.De två sista författarna delar sistaförfattarskapet</p

Cost Effectiveness of Primary Stenting in the Superficial Femoral Artery for Intermittent Claudication : Two Year Results of a Randomised Multicentre Trial

Objective: Invasive treatment of intermittent claudication (IC) is commonly performed, despite limited evidence of its cost effectiveness. IC symptoms are mainly caused by atherosclerotic lesions in the superficial femoral artery (SFA), and endovascular treatment is performed frequently. The aim of this study was to investigate its cost effectiveness vs. non-invasive treatment. Methods: One hundred patients with IC due to lesions in the SFA were randomised to treatment with primary stenting, best medical treatment (BMT) and exercise advice (stent group), or to BMT and exercise advice alone (control group). Patients were recruited at seven hospitals in Sweden. For this analysis of cost effectiveness after 24 months, 84 patients with data on quality adjusted life years (QALY; based on the EuroQol Five Dimensions EQ-5D 3L™ questionnaire) were analysed. Patient registry and imputed cost data were used for accumulated costs regarding hospitalisation and outpatient visits. Results: The mean cost per patient was €11 060 in the stent group and €4 787 in the control group, resulting in a difference of €6 273 per patient between the groups. The difference in mean QALYs between the groups was 0.26, in favour of the stent group, which resulted in an incremental cost effectiveness ratio (ICER) of € 23 785 per QALY. Conclusion: The costs associated with primary stenting in the SFA for the treatment of IC were higher than for exercise advice and BMT alone. With concurrent improvement in health related quality of life, primary stenting was a cost effective treatment option according to the Swedish national guidelines (ICER < €50 000 – €70 000) and approaching the UK's National Institute for Health and Care Excellence threshold for willingness to pay (ICER < £20 000 – £30 000). From a cost effectiveness standpoint, primary stenting of the SFA can, in many countries, be used as an adjunct to exercise training advice, but it must be considered that successful implementation of structured exercise programmes and longer follow up may alter these findings

Performance of a feature-based algorithm for 3D-3D registration of CT angiography to cone-beam CT for endovascular repair of complex abdominal aortic aneurysms

Background: A crucial step in image fusion for intraoperative guidance during endovascular procedures is the registration of preoperative computed tomography angiography (CTA) with intraoperative Cone Beam CT (CBCT). Automatic tools for image registration facilitate the 3D image guidance workflow. However their performance is not always satisfactory. The aim of this study is to assess the accuracy of a new fully automatic, feature-based algorithm for 3D3D registration of CTA to CBCT. Methods: The feature-based algorithm was tested on clinical image datasets from 14 patients undergoing complex endovascular aortic repair. Deviations in Euclidian distances between vascular as well as bony landmarks were measured and compared to an intensity-based, normalized mutual information algorithm. Results: The results for the feature-based algorithm showed that the median 3D registration error between the anatomical landmarks of CBCT and CT images was less than 3mm. The feature-based algorithm showed significantly better accuracy compared to the intensity-based algorithm (p<0.001). Conclusion: A feature-based algorithm for 3D image registration is presented