Update on covered endovascular reconstruction of the aortic bifurcation

Vascular ◽  
2020 ◽  
Vol 28 (3) ◽  
pp. 225-232
Author(s):  
Michel MPJ Reijnen

Objective The covered endovascular reconstruction of the aortic bifurcation (CERAB) technique was introduced in 2009 in order to provide an anatomically and physiologically optimal endovascular reconstruction of the aortic bifurcation. Method In the current review, all available evidence on this technique was summarized. Results In vitro studies have shown a more favorable geometry of CERAB compared to kissing stents, leading to better local flow conditions. The results of CERAB are at least as good as those achieved with kissing stents in a more complex group of treated patients. The mid-term patency rates approach those of surgical reconstruction. Initial data show that the technique can also be used in combination with chimney grafts in order to preserve side branches. Conclusion CERAB has proven to be the most optimal endovascular treatment option for aorto-iliac occlusive disease with regard to geometry and flow and is related to promising clinical outcomes. Prospective and comparative trials are necessary to elucidate the most optimal treatment algorithm for patients with aorto-iliac occlusive disease.

2019 ◽  
Vol 19 (2) ◽  
pp. 681-692
Author(s):  
P. S. Zun ◽  
A. J. Narracott ◽  
P. C. Evans ◽  
B. J. M. van Rooij ◽  
A. G. Hoekstra

Abstract Endothelial cells (ECs) play a major role in the healing process following angioplasty to inhibit excessive neointima. This makes the process of EC healing after injury, in particular EC migration in a stented vessel, important for recovery of normal vessel function. In that context, we present a novel particle-based model of EC migration and validate it against in vitro experimental data. We have developed a particle-based model of EC migration under flow conditions in an in vitro vessel with obstacles. Cell movement in the model is a combination of random walks and directed movement along the local flow velocity vector. For model calibration, a set of experimental data for cell migration in a similarly shaped channel has been used. We have calibrated the model for a baseline case of a channel with no obstacles and then applied it to the case of a channel with ridges on the bottom surface, representative of stent strut geometry. We were able to closely reproduce the cell migration speed and angular distribution of their movement relative to the flow direction reported in vitro. The model also reproduces qualitative aspects of EC migration, such as entrapment of cells downstream from the flow-disturbing ridge. The model has the potential, after more extensive in vitro validation, to study the effect of variation in strut spacing and shape, through modification of the local flow, on EC migration. The results of this study support the hypothesis that EC migration is strongly affected by the direction and magnitude of local wall shear stress.


Biomolecules ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 99 ◽  
Author(s):  
Danja J. Den Hartogh ◽  
Evangelia Tsiani

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by insulin resistance and hyperglycemia and is associated with personal health and global economic burdens. Current strategies/approaches of insulin resistance and T2DM prevention and treatment are lacking in efficacy resulting in the need for new preventative and targeted therapies. In recent years, epidemiological studies have suggested that diets rich in vegetables and fruits are associated with health benefits including protection against insulin resistance and T2DM. Naringenin, a citrus flavanone, has been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, immunomodulatory and antidiabetic properties. The current review summarizes the existing in vitro and in vivo animal studies examining the anti-diabetic effects of naringenin.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1207
Author(s):  
Andrea Vítečková Wünschová ◽  
Adam Novobilský ◽  
Jana Hložková ◽  
Peter Scheer ◽  
Hana Petroková ◽  
...  

Diseases with the highest burden for society such as stroke, myocardial infarction, pulmonary embolism, and others are due to blood clots. Preclinical and clinical techniques to study blood clots are important tools for translational research of new diagnostic and therapeutic modalities that target blood clots. In this study, we employed a three-dimensional (3D) printed middle cerebral artery model to image clots under flow conditions using preclinical imaging techniques including fluorescent whole-body imaging, magnetic resonance imaging (MRI), and computed X-ray microtomography (microCT). Both liposome-based, fibrin-targeted, and non-targeted contrast agents were proven to provide a sufficient signal for clot imaging within the model under flow conditions. The application of the model for clot targeting studies and thrombolytic studies using preclinical imaging techniques is shown here. For the first time, a novel method of thrombus labeling utilizing barium sulphate (Micropaque®) is presented here as an example of successfully employed contrast agents for in vitro experiments evaluating the time-course of thrombolysis and thus the efficacy of a thrombolytic drug, recombinant tissue plasminogen activator (rtPA). Finally, the proof-of-concept of in vivo clot imaging in a middle cerebral artery occlusion (MCAO) rat model using barium sulphate-labelled clots is presented, confirming the great potential of such an approach to make experiments comparable between in vitro and in vivo models, finally leading to a reduction in animals needed.


2010 ◽  
Vol 8 (7) ◽  
pp. 516
Author(s):  
Alexander Rolls ◽  
Robert S.M. Davies ◽  
Andrew W. Bradbury ◽  
Donald J. Adam

2015 ◽  
Vol 129 (5) ◽  
pp. 410-415 ◽  
Author(s):  
I Syed ◽  
V S Sunkaraneni

AbstractBackground:There are currently no guidelines in the UK for the specific management of hereditary haemorrhagic telangiectasia related epistaxis. The authors aimed to review the literature and provide an algorithm for the management of hereditary haemorrhagic telangiectasia related epistaxis.Method:The Medline and Embase databases were interrogated on 15 November 2013 using the search items ‘hereditary haemorrhagic telangiectasia’ (title), ‘epistaxis’ (title) and ‘treatment’ (title and abstract), and limiting the search to articles published in English.Results:A total of 46 publications were identified, comprising 1 systematic review, 2 randomised, controlled trials, 27 case series, 9 case reports, 4 questionnaire studies and 3in vitrostudies.Conclusion:There is a lack of high-level evidence for the use of many of the available treatments for the specific management of epistaxis in hereditary haemorrhagic telangiectasia. Current management should be based on a multidisciplinary team approach involving both a hereditary haemorrhagic telangiectasia physician and an ENT surgeon, especially when systemic therapy is being considered. The suggested treatment algorithm considers that the severity of epistaxis merits intervention at different levels of the treatment ladder. The patient should be assessed using a reproducible validated assessment tool, for example an epistaxis severity score, to guide treatment. More research is required, particularly in the investigation of topical agents targeting the development and fragility of telangiectasiae in hereditary haemorrhagic telangiectasia.


2021 ◽  
Author(s):  
Marco Testaguzza ◽  
Mehdi Benhassine ◽  
Haroun Frid ◽  
Laurence Gebhart ◽  
Karim Zouaoui Boudjeltia ◽  
...  

Abstract Ischemic Stroke is the most frequent type of stroke and is subject to many studies investigating prevention means. Avoiding the difficulties and ethical problems of experimental in-vivo research, in-vitro testing is a convenient way of studying in controlled conditions the morphological impact and mechanical aspects of emboli dynamics. This in-vitro study was performed with two realistic silicone aortic-arch phantoms submitted to physiological pulsatile flow conditions. In the in-vitro test bed, using automatic image tracking and analysis, it was made possible detecting and tracking artificial spherical emboli candidates circulating in the anatomic aortic-arch models under a realistic based-patient blood flow profile. The emboli trajectories as well as their repartition in the different supra-aortic branches are presented for the two aortic-arch geometries obtained from CT scans. Through a statistical analysis performed with several artificial emboli sizes, the experimental study shows that the repartition percentages of the emboli closely follow the flowrate repartition percentages for both aortic-arch models, suggesting that higher flowrates lead to higher concentrations of emboli in a given artery. Sets of human thrombi were also injected and the repartition percentages have been established, giving the same trend as for artificial emboli.


Author(s):  
Luis Fernando García ◽  
Juan Carlos Gómez-Rodríguez ◽  
Luis Felipe Cabrera-Vargas ◽  
Martin Contreras ◽  
Ivan David Lozada-Martínez ◽  
...  

2016 ◽  
Vol 40 (3) ◽  
pp. 746-761 ◽  
Author(s):  
Weiling Liu ◽  
Chao Tan ◽  
Feng Dong

Two-phase flow widely exists in many industries. Understanding local characteristics of two-phase flow under different flow conditions in piping systems is important to design and optimize the industrial process for higher productivity and lower cost. Air–water two-phase flow experiments were conducted with a 16×16 conductivity wire-mesh sensor (WMS) in a horizontal pipe of a multiphase flow facility. The cross-sectional void fraction time series was analysed by the probability density function (PDF), which described the void fraction fluctuation at different flow conditions. The changes and causes of PDFs during a flow regime transition were analysed. The local structure and flow behaviour were characterized by the local flow spectrum energy analysis and the local void fraction distribution (horizontal, vertical and radial direction) analysis. Finally, three-dimensional transient flow fluctuation energy evolution and characteristic scale distribution based on wavelet analysis of air–water two-phase flow were presented, which revealed the structural features of each phase in two-phase flow.


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