Download or read book Biomechanical Assessment of Abdominal Aortic Aneurysm Rupture Risk and Growth Using Clinical Data a Probabilistic Approach written by Lukas Bruder and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of a Comprehensive Modeling Characterization Rupture Risk Assessment and Visualization Pipeline for Abdominal Aortic Aneurysms written by Golnaz Jalalahmadi and published by . This book was released on 2020 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Abdominal aortic aneurysms (AAA) is a dilation of the abdominal aorta, typically within the infra-renal segment of the vessel that cause an expansion of at least 1.5 times the normal vessel diameter. It is becoming a leading cause of death in the United States and around the world, and consequentially, in 2009, the Society for Vascular Surgery (SVS) practice guidelines expressed the critical need to further investigate the factors associated with the risk of AAA rupture, along with potential treatment methods. For decades, the maximum diameter (Dmax) was introduced as the main parameter used to assess AAA behavior and its rupture risk. However, it has been shown that three main categories of parameters including geometrical indices, such as the maximum transverse diameter, biomechanical parameters, such as material properties, and historical clinical parameters, such as age, gender, hereditary history and life-style affect AAA and its rupture risk. Therefore, despite all efforts that have been undertaken to study the relationship among different parameters affecting AAA and its rupture, there are still limitations that require further investigation and modeling; the challenges associated with the traditional, clinical quality images represent one class of these limitations. The other limitation is the use of the homogenous hyper-elastic material property model to study the entire AAA, when, in fact, there is evidence that different degrees of degradation of the elastin and collagen network of the AAA wall lead to different regions of the AAA exhibiting different material properties, which, in turn, affect its biomechanical behavior and rupture. Moreover, the effects of all three main categories of parameters need to be considered simultaneously and collectively when studying the AAAs and their rupture, so once again, the field can further benefit from such studies. Therefore, in this work, we describe a comprehensive pipeline consisting of three main components to overcome some of these existing limitations. The first component of the proposed method focuses on the reconstruction and analysis of both synthetic and human subject-specific 3D models of AAA, accompanied by a full geometric parameter analysis and their effects on wall stress and peak wall stress. The second component investigates the effect of various biomechanical parameters, specifically the use of various homogeneous and heterogeneous material properties to model the behavior of the AAA wall. To this extent, we introduce two different patient-specific regional material property models to better mimic the physiological behavior of the AAA wall. Finally, the third component utilizes machine learning methods to develop a comprehensive predictive model that incorporates the effect of the geometrical, biomechanical and historical clinical data to predict the rupture severity of AAA in a patient-specific manner. This is the first comprehensive semi-automated method developed for the assessment of AAA. Our findings illustrate that using a regional material property model that mimics the realistic heterogeneity of the vessel's wall leads to more reliable and accurate predictions of AAA severity and associated rupture risk. Additionally, our results indicate that using only Dmax as an indicator for the rupture risk is insufficient, while a combination of parameters from different sources along with PWS could serve as a more reliable rupture assessment. These methods can help better characterize the severity of AAAs, better predict their associated rupture risk, and, in turn, help clinicians with earlier, patient-customized diagnosis and patient-customized treatment planning approaches, such as stent grafting."--Abstract.
Download or read book Abdominal Aortic Aneurysm written by Igor Koncar and published by . This book was released on 2019-05-29 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, intended for all physicians who are facing patients with abdominal aortic aneurysms, has been assembled by interested, invited authors and contains important topics from basic research to clinical practice. Experimental studies focus on biomechanical and biochemical factors. In clinical practice, the decision to treat, based on risk-benefit ratio, is very delicate in patients with concomitant malignant diseases. Periprocedural risk is determined by anatomy, while aneurysms causing neck pain are one of the most frequent challenges for both open and endovascular methods. Finally, careful planning is crucial. Postoperative complications are different from post-implantation syndrome, which is still an underestimated problem, toward detection and treatment of endoleaks and eventual conversion.
Download or read book Aneurysm written by Yasuo Murai and published by IntechOpen. This book was released on 2012-08-29 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book's focus is on diagnosis and treatment of intracranial aneurysm, abdominal and thoracic aortic aneurysms. It addresses neurosurgical, vascular and cardiothoracic surgeons and interventional radiologists, but also anyone engaged in vascular medicine. It presents is an effort to collect an up-to-date account of existing knowledge, involving recent developments in this field. Various experts described details of established knowledge or newly recognized advances associated with diagnosis, treatment, perioperative management and mechanism. This is the first book that deals with the whole body aneurysm, such as cerebral aneurysm, abdominal aneurysm, and splenial aneurysm and to learn the latest developments in other fields is always useful. I hope this book will be used worldwide by vascular surgeons and interventionalists enhancing their knowledge and stimulating the advancement of this field.
Download or read book Biomechanic and Hemodynamic Perspectives in Abdominal Aortic Aneurysm Rupture Risk Assessment written by Nikolaos Kontopodis and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abdominal aortic aneurysms (AAAs) pose a significant source of mortality for the elderly, especially if they go on undetected and ultimately rupture. Therefore, elective repair of these lesions is recommended in order to avoid risk of rupture which is associated with high mortality. Currently, the risk of rupture and thus the indication to intervene is evaluated based on the size of the AAA as determined by its maximum diameter. Since AAAs actually present original geometric configurations and unique hemodynamic and biomechanic conditions, it is expected that other variables may affect rupture risk as well. This is the reason why the maximum diameter criterion has often been proven inaccurate. The biomechanical approach considers rupture as a material failure where the stresses exerted on the wall outweigh its strength. Therefore, rupture depends on the pointwise comparison of the stress and strength for every point of the aneurysmal surface. Moreover, AAAs hemodynamics play an essential role in AAAs natural history, progression and rupture. This chapter summarizes advances in AAAs rupture risk estimation beyond the ,Äúone size fits all,Äù maximum diameter criterion.
Download or read book Biomechanics and Mechanobiology of Aneurysms written by Tim McGloughlin and published by Springer Science & Business Media. This book was released on 2011-09-15 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cardiovascular disease is the leading cause of morbidity and premature death of modern era medicine. It is estimated that approximately 81 million people in the United States (US) currently have one or more of the many forms of cardiovascular disease, resulting in 1 in every 2.8 deaths, or 900,000 deaths per year. 40% of all deaths in Europe are a result of cardiovascular disease in people under the age of 75. Aneurysms form a significant portion of these cardiovascular related deaths and are defined as a permanent and irreversible localised dilation of a blood vessel greater than 50% of its normal diameter. Although aneurysms can form in any blood vessel, the more lethal aneurysms develop in the cranial arteries, and in the thoracic aorta and abdominal aorta. Frequently aneurysms are undetected and if left untreated may eventually expand until rupture with very high levels of morbidity and mortality. The biomechanics and mechanobiology of aneursymal diseases are not fully understood and this monograph aims to provide new insights into aneurysm aetiology and behavior based on the most recent biomechanics research related to this important topic. The contributors to this volume bring together a unique blend of expertise in experimental, computational and tissue biomechanics relating to aneurysm behavior and enable the reader to gain a fresh understanding of key factors influencing aneurysm behavior and treatment. Biological risk factors such as tobacco smoking, sex, age, hypertension, family history and mechanobiological risk factors such as aneurysm geometry and shape as well as mechanical properties of the diseased tissues are considered in detail as are many of the diagnostic and treatment options.
Download or read book The Role of Abdominal Aortic Aneurysm Wall Biomechanics in Endovascular Repair Assessment written by Zinan He and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Cardiovascular disease is a leading cause of death around the world. In particular, abdominal aortic aneurysm (AAA) is a top silent killer and even claimed the life of our eminent scientist Albert Einstein. Symptoms often only appear in the late stages, and since AAA involves the main artery carrying blood from the heart to the torso, it may trigger catastrophic events such as rupture and coincides with a mortality up to 90%. The prevalence in western countries is especially high, around 20,000 patients are diagnosed with AAA every year in Canada, and AAA rupture has been ranked the 15th leading cause of death for the past two decades in the United Sates. Endovascular repair (EVAR), a minimally invasive AAA treatment, was introduced in the 90’s and is considered as a promising option compared to the traditional open surgery. Regardless of the significant reduction in surgical risks and recovery time, no difference has been reported for the long-term outcome, mainly due to graft related complications. Therefore, better understanding the biomechanics of AAA, particularly in contact with endovascular devices, will provide an essential path to improve endovascular treatments.Although the biomechanics of AAA has been extensively investigated, efforts have mostly been devoted to the risks of major AAA characteristics associated with vascular rupture, such as stiffened wall, gigantic thrombus and calcification. The roles of those characteristics during the interaction with endovascular devices remain to be elucidated. Moreover, controversial understanding on the role of calcification (Ca) persists, partly due to its complicated nature and morphological variability, often resulting in oversimplification or exclusion from clinical evaluations. The intrinsic property of Ca has always been considered, however the combined effects of Ca shapes and locations have been questioned but not yet addressed. Besides, most studies have focused on major AAA characteristics, but rarely on the surrounding tissues, such as the abdominal fat despite its high prevalence. Hence, further research on the biomechanical response of AAA during EVAR, taking into account both the major AAA characteristics and the surrounding tissues, is sought.Consequently, the main objective of this thesis is to provide insight into the role of AAA wall biomechanics, specifically for the aortic Ca and surrounding tissues, in EVAR assessment. A novel quantitative and qualitative analysis, using 3D models reconstructed from clinical data to describe the extent, shape and location of Ca, has been conducted to investigate the effects of Ca morphological characteristics on EVAR outcomes. In addition, a series of hydrogel-based anthropomorphic mockups simulating the mechanical, anatomical and pathological characteristics of AAA have been developed for the first time, in order to evaluate the biomechanical interaction between endovascular devices and AAA, with and without the presence of surrounding abdominal fat. Results from Ca analysis confirmed that, not only the intrinsic properties but also the morphological characteristics of Ca, can together alter the global behavior of AAA, thus playing an essential role in EVAR assessment. Specifically, including the combined effects from Ca morphological characteristics can lead to very different prediction compared to conventional assessment, where the intrinsic property is merely considered. Furthermore, results from AAA mockup analysis highlighted the indispensable role of surrounding tissues, not only the spine but also the abdominal fat, as to account for realistic interactions with endovascular devices. The discoveries and novel approaches within the scope of this thesis have potential clinical significance which, with future revisions and validation, could improve the current knowledge in AAA biomechanics and EVAR assessment"--
Download or read book Abdominal Aortic Aneurysms written by Barry J. Doyle and published by Nova Science Publishers. This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancements in medical imaging technology over recent years have revolutionised the management and treatment of all aspects of health care. Computed tomography and magnetic resonance imaging have led to the development of reconstruction software that allows internal bodily structures to be easily visualised in 3D. These developments have led to improved surgical planning and treatment. The assessment of abdominal aortic aneurysms (AAA) has benefited greatly from these advancements. There is currently much debate as when to surgically repair these life-threatening dilations of the aorta and 3D reconstructions of AAAs have led to many new diagnostic tools and rupture-prediction indices. This book explores recent developments in this area.
Download or read book Advanced Computer Modeling of Abdominal Aortic Aneurysms to Predict Risk of Rupture written by Omar Altuwaijri and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An abdominal aortic aneurysm (AAA) is an abnormal enlargement of the aorta which is related to weakness of the vessel wall (associated with degradation of connective tissue), and if left untreated will lead to rupture and cause death in 78% to 94% of cases. Approximately 7,000 deaths each year in the United Kingdom are caused by AAA rupture. AAA repair requires surgical intervention but the surgery itself has a mortality rate of about 5% in patients with stable AAA. The decision to undertake the surgery is made depending on the aortic maximum diameter of ≥5 cm. However, it is observed that rupture sometimes occurs in aneurysms with smaller diameter, thereby creating the need for better criteria for surgical intervention. Therefore, (biomechanical) indicators of AAA rupture were introduced as a superior criterion to the maximum diameter for predicting the risk AAA rupture. Several studies that have been conducted on abdominal aortic aneurysms have suggested that peak wall stress may be a more reliable predictor of the risk of AAA rupture. This thesis is a continuation of a previous study undertaken at the University of Hull which investigated a number of biomechanical factors that affect the AAA wall stress magnitude and distribution. Novel results were gained which may help in the understanding of AAA growth and rupture events. For the first time, it is proposed that aspect ratio has an effect on the stress magnitude, location and distribution of the outer wall of AAA. These findings were used to introduce an empirical relationship between the aneurysm aspect ratio and maximum wall stress. This empirical relationship could be used as an additional clinical indicator to predict the location and magnitude of maximum wall stress where a rupture may develop. Analysis of the porosity of the thrombus was introduced for the first time in this work using the simulation of mass transport of blood flow in an AAA, showing novel results for the possible role of blood flow on the site of growth and rupture for AAA. Furthermore, the results of this research may also explain the conflicting views on aneurysm shape and the role of the thrombus as previously reported in the literature. The work carried out in this research used simplified AAA geometries to allow the isolation of specific aneurysm parameters. Clearly, the next stage would include the application of the ideas and results developed here to more complex patient-specific geometries.
Download or read book Changes in Geometric Configuration and Biomechanical Parameters of a Rapidly Growing Abdominal Aortic Aneurysm May Provide Insight in Aneurysms Natural History and Rupture Risk written by Dresden Dresden Press and published by . This book was released on 2016-01-09 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abdominal aortic aneurysms (AAA) are currently being treated based on the maximum diameter criterion which has often been proven insufficient to determine rupture risk in case of every AAA. We analyzed a rare case of an AAA which presented an extremely fast growth focusing on biomechanical determinants that may indicate a high risk profile. The examination of such a case is expected to motivate future research towards patient-specific rupture risk estimations.
Download or read book Biomechanics of the Aorta written by T. Christian Gasser and published by Elsevier. This book was released on 2024-06-18 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics of the Aorta: Modelling for Patient Care is a holistic analysis of the aorta towards its biomechanical description. The book addresses topics such as physiology, clinical imaging, tissue and blood flow modeling, along with knowledge that is needed in diagnostics, aortic rupture prediction, assist surgical planning, and more. It encompasses a wide range of topics from the basic sciences (Vascular biology, Continuum mechanics, Image analysis) to clinical applications, as well as describing and presenting computational studies and experimental benches to mimic, understand and propose the best treatment of aortic pathologies. The book begins with an introduction to the fundamental aspects of the anatomy, biology and physiopathology of the aorta and proceeds to present the main computational fluid dynamic studies and biomechanical and mechanobiological models developed over the last decade. With approaches, methodologies and findings from contributors all over the world, this new volume in the Biomechanics of Living Organs series will increase understanding of aortic function as well as improve the design of medical devices and clinical interventions, including surgical procedures. Represents a comprehensive means for those involved in the aortic research and the related developments in the industry Introduces the most recent imaging technologies to characterize factors, such as aortic geometry, mechanical properties of the aortic tissue, and the local cellular activity in the vessel wall Synthesizes advances in vascular biomechanics, medical imaging and computational finite element fluid and solid models to increase understanding of aorta function
Download or read book Biomedical Technology written by Peter Wriggers and published by Springer. This book was released on 2017-08-29 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of new mathematical models, computational simulations and experimental tests in the field of biomedical technology, and covers a wide range of current research and challenges. The first part focuses on the virtual environment used to study biological systems at different scales and under multiphysics conditions. In turn, the second part is devoted to modeling and computational approaches in the field of cardiovascular medicine, e.g. simulation of turbulence in cardiovascular flow, modeling of artificial textile-reinforced heart valves, and new strategies for reducing the computational cost in the fluid-structure interaction modeling of hemodynamics. The book’s last three parts address experimental observations, numerical tests, computational simulations, and multiscale modeling approaches to dentistry, orthopedics and otology. Written by leading experts, the book reflects the remarkable advances that have been made in the field of medicine, the life sciences, engineering and computational mechanics over the past decade, and summarizes essential tools and methods (such as virtual prototyping of medical devices, advances in medical imaging, high-performance computing and new experimental test devices) to enhance medical decision-making processes and refine implant design. The contents build upon the International Conference on Biomedical Technology 2015 (ICTB 2015), the second ECCOMAS thematic conference on Biomedical Engineering, held in Hannover, Germany in October 2015.
Download or read book Ultrafast Ultrasound Imaging written by Hideyuki Hasegawa and published by MDPI. This book was released on 2018-09-21 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Ultrafast Ultrasound Imaging" that was published in Applied Sciences
Download or read book Aortic Dissection and Related Syndromes written by Ragavendra Baliga and published by Springer Science & Business Media. This book was released on 2007-04-03 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of the-art publication is a result of the combined efforts of participants from the International Registry of Aortic Dissection (IRAD). It is the most comprehensive reference on aortic dissection The book has been divided into sections. Each chapter provides a succinct overview of the current clinical literature and incorporates illustrations for further explanation.
Download or read book Thoracic Aortic Diseases written by Hervé Rousseau and published by Springer Science & Business Media. This book was released on 2006-10-05 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides information on the acquired and genetic basis of aortic diseases as well as giving a global perspective on therapeutic alternatives. The new concept of a team approach with surgeons working together with both interventional radiologists and specialists to repair the aorta is the trademark of this book. New material and new viewpoints are provided to practicing physicians in this modern approach to the treatment of disorders of the aorta.
Download or read book The Cause and Management of Aneurysms written by Roger Malcolm Greenhalgh and published by Thomas Allen Publishers. This book was released on 1990 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work offers detailed reference information on the principal aneurysm sites. It also provides guidance on the mechanism by which aneurysms occur; modern investigative approaches; special features of aneurysmal diseases in different nationalities; and conservation and surgical management.
Download or read book Material Parameter Identification and Inverse Problems in Soft Tissue Biomechanics written by Stéphane Avril and published by Springer. This book was released on 2016-10-12 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles in this book review hybrid experimental-computational methods applied to soft tissues which have been developed by worldwide specialists in the field. People developing computational models of soft tissues and organs will find solutions for calibrating the material parameters of their models; people performing tests on soft tissues will learn what to extract from the data and how to use these data for their models and people worried about the complexity of the biomechanical behavior of soft tissues will find relevant approaches to address this complexity.
