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Computational Methods in Cardiovascular Mechanics
Published in Michel R. Labrosse, Cardiovascular Mechanics, 2018
F. Auricchio, M. Conti, A. Lefieux, S. Morganti, A. Reali, G. Rozza, A. Veneziani
Cardiovascular disease is the generic name given to dysfunctions of the cardiovascular system such as atherosclerosis, hypertension, coronary heart disease, heart failure, and stroke. Cardiovascular disease is still the main cause of death in Europe, leading to almost twice as many deaths as cancer across the continent (Townsend et al., 2015). In particular, within the broad family of CVD, we will refer in the following text to focal obstructive lesions or stenosis of the arteries (coronaries, carotid, and limb arteries) and heart valves or the abnormal localized bulging of the aorta called aneurysm. The use of endovascular approaches has revolutionized the treatment of this class of vascular diseases, which used to be treated by combining open surgery with medical management. In fact, in recent decades, endovascular therapy of vascular diseases has broadened its field of applications—from coronary stenting to treat atherosclerotic stenosis to the endovascular replacement of aortic valve. As mentioned earlier, the broadening of indications for endovascular therapy has been supported by improvements in the design and technological content of endovascular devices. Such advancements have been supported by dedicated biomechanical analyses of the artery–device interactions through computational tools, such as structural finite element analysis (FEA) and computational fluid dynamics (CFD), which are nowadays extensively used during the design of devices (Alaimo et al., 2017), for preoperative planning (Morganti et al., 2016, de Jaegere et al., 2016), or in diagnostics (Gasser et al., 2016; Gaur et al., 2017), as discussed in the following text, which deals with different aspects of simulating tissues and structures in cardiovascular mechanics. In particular, we will focus herein on the simulation of endovascular treatments of peripheral arteries (e.g., carotid artery) and the aortic valve, and we will neglect coronary stenting, which deserves a dedicated dissertation, as reported in (Morlacchi et al., 2013).
Competitive Advantage and Market Introduction of PHA Polymers and Potential Use of PHA Monomers
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Konstantina Kourmentza, Vasiliki Kachrimanidou, Olga Psaki, Chrysanthi Pateraki, Dimitrios Ladakis, Apostolos Koutinas
Recent reviews have extensively elaborated on the previous research conducted with respect to applications of PHA, distinguishing them primarily between biomedical and non-medical end uses [41,43]. Biomedical applications include heart valve tissue engineering to improve implications in cardiovascular diseases, bone and cartilage tissue engineering, nerve repair and regeneration, and drug delivery matrices, among others. For instance, tissue-engineered autologous aortic grafts using copolymers including PHA were prepared and evaluated as vascular substitutes. It is believed that PHA vascular tissue engineering will enable the tailored design of heart valves to replace conventional synthetic prosthetic valves, with enhanced durability. Recent progress on tissue engineering and stem cells are anticipated to provide solutions for patients with brain damage but also for the regeneration of injured or damaged nerve cells, through the utilization of PHA, e.g., P(3HB) and P(4HB), for nerve guide conduit formulation [41]. Significant research has been also performed to evaluate the exploitation of PHA as drug delivery carrier systems. Biocompatibility and biodegradability of PHA, which can be tailored using manifold approaches to include specific monomeric units, have enabled the administration of bioactive compounds (antibiotics, antitumor, and anticancer drugs) in specific sites of actions. Both scl-PHA and mcl-PHA have been successful for drug delivery that is correlated with their crystallinity, hydrophobicity, and melting behavior [81,82]. It has been generally indicated that P(3HB), P(3HB-co-3HV), P(4HB), P(3HB-co-3HHx), and PHO have been implemented to generate sutures, repair devices and compartments, cardiovascular grafts, orthopedic pins, guided tissue repair, cartilage repair devices, etc. [83]. A broad spectrum of biomedical applications has been evidenced so far and the exquisite advantages of biodegradability and biocompatibility along with the potential to produced tailor-made PHA by fine tuning of the monomeric units has led to research to alleviate several health issues.
Cyclopeptide-β-cyclodextrin/γ-glycerol methoxytrimethoxysilane film for potential vascular tissue engineering scaffolds
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Heyi Mao, Yidan Zhang, Lei Wang, Anduo Zhou, Shanfeng Zhang, Jing Cao, Huang Xia
Cardiovascular diseases account for the highest fatality rate worldwide [1] and are estimated to reach 23.3 million deaths by 2030 [2,3]. Common clinical treatments for cardiovascular diseases include decellularized stent implantation, drug therapy, and vascular bypass transplantation [4]. Drug treatment and decellularized stent implantation cannot fundamentally solve the problem and are prone to immune rejection [5,6]. Although vascular bypass transplantation is currently an effective treatment, the lack of autologous vessels has led to the use of vascular allografts and synthetic grafts, including polyethylene terephthalate and expanded polytetrafluoroethylene grafts for the treatment of cardiovascular diseases. These grafts can replace large-diameter blood vessels [7,8]. However, artificial blood vessels prepared from synthetic materials generally have shortcomings such as low biocompatibility and poor endothelial cell adhesion on the surface of the material. They manifest as small-diameter artificial vascular grafts as very easy activation of coagulation reactions to form thrombosis after the surface of a vessel comes into contact with blood, resulting in unsatisfactory long-term patency [9], because of the high incidence of thrombosis, stenosis, and infection, the currently available vascular prostheses cannot effectively solve the problem of small-diameter (<6 mm) vascular transplants [10]. Tissue engineering provides new avenues for solving the problems of small-diameter blood vessels.
Role of the left coronary artery geometry configuration in atherosusceptibility: CFD simulations considering sPTT model for blood
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
E. Miranda, L.C. Sousa, C.C. António, C.F. Castro, S.I.S. Pinto
The motivation of this hemodynamic study is related to the quantification of atherosclerotic disease development in left coronary arteries (LCA) of apparently healthy patients. Thus, numerical simulations describing the hemodynamics very close to the reality of each patient, such as the deformability of blood vessels and the viscoelastic property of blood, should be performed. Determining the tendency of atherosclerosis appearance in an apparently healthy patient, through computational processes, helps in prevention, diagnosis and treatment of these pathologies. With the early detection of atherosclerosis, medicine combined with engineering becomes a strong ally in reducing the mortality rate caused by cardiovascular diseases, especially coronary artery diseases. Therefore, the hemorheology, the blood flow modelling and the discretization of blood vessels stand out in this study.
An Effective Method for Online Disease Risk Monitoring
Published in Technometrics, 2020
Many diseases (e.g., chronic diseases) can be prevented or treated if they can be detected early. Disease early detection and prevention (DEDAP) is thus a critically important research problem in public health and medical research. To this end, past medical research has discovered major risk factors for many different diseases. For instance, the discovered major risk factors of cardiovascular diseases (CVDs) include high blood pressure, high cholesterol level, obesity, tobacco use, lack of physical activity, diabetes, unhealthy diet, age, family history, and more (e.g., Mendis, Puska, and Norrving 2011). After the major risk factors of a disease are found, medical doctors/researchers can use them for disease prediction and diagnostics. Most current methods for this purpose compare the readings of the risk factors of a given patient collected at a given time point cross-sectionally with those of a properly chosen healthy population. These methods, however, have not made use of all history data of the given patient. This article aims to develop a novel and effective new statistical method for DEDAP, which effectively combines cross-sectional comparisons between the given patient and the healthy population and sequential monitoring over time of a properly quantified risk to a disease in question of the given patient. Thus, both the data collected at the current time point and all history data are used in the new method; consequently, the disease can be detected effectively.