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Predicting the Biomechanics of the Aorta Using Ultrasound
Published in Ayman El-Baz, Jasjit S. Suri, Cardiovascular Imaging and Image Analysis, 2018
Mansour AlOmran, Alexander Emmott, Richard L. Leask, Kevin Lachapelle
Thoracic aortic disease continues to be associated with a significant burden of morbidity and mortality in the general population. Disease of the thoracic aorta is due to aneurysm and/or dissection. An aneurysm is by definition an aortic diameter twice the normal size. This can lead to frank rupture or dissection then rupture. A dissection is a tearing of the inner lumen of the aorta such that the layers of the media separate and blood flows into a false lumen as well as the true lumen. An aortic rupture and an ascending aortic dissection (Type A) are considered surgical emergencies. The mortality is high and generally over 50% are dead without surgical treatment within two weeks. Despite improvement in diagnostics and advanced surgical techniques, mortality rates following surgery for acute aortic syndromes such as a rupture or type A aortic dissection continue to be associated with an overall mortality of 20–25% and significant morbidity such as stroke [1–5]. This high mortality following acute life-saving surgery is contrasted by the much lower risk of mortality (1.5–2.5%) when the ascending aortic aneurysm is repaired electively [3, 4, 6, 7]. This comparison illustrates the critical importance of early detection of individuals at risk for acute aortic syndromes such as dissection and rupture. Currently, most aortic aneurysms are detected incidentally when undergoing imaging for an unrelated issue, as aortic disease is generally asymptomatic until a first presentation of catastrophic dissection or even sudden death [9].
Adhesive Biomaterials for Tissue Repair and Reconstruction
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
Migration and embolization of the albumin–glutaraldehyde polymer can also cause serious complications. Albumin–glutaraldehyde glue can leak through suture holes in aortic tissue and vascular grafts [182], and migrate to block distal blood vessels. In one clinical report, embolization of the glue led to blockage of the right and left coronary arteries, resulting in a fatal right ventricular heart attack [183]. In another report, two patients experienced acute loss of blood perfusion to the limbs, due to embolization of albumin–glutaraldehyde polymer after aortic dissection repair [184]. One patient required surgery to restore blood flow to the leg, and the other patient required surgery to restore blood flow to the arm. In addition, migration of the glue has resulted in cardiac valve malfunction. In one case report, one patient experienced blockage of a mechanical mitral valve leaflet following albumin–glutaraldehyde glue application [185], and in another case, one patient experienced malfunction of a prosthetic aortic valve due to albumin–glutaraldhehyde adhesive [186].
Experimental Methods in Cardiovascular Mechanics
Published in Michel R. Labrosse, Cardiovascular Mechanics, 2018
The study of tear propagation is especially relevant to aortic dissection, wherein blood infiltrates an initial injury of the inner layer of the aorta, causing the inner and middle layers of the aorta to separate (dissect). If the blood-filled channel ruptures through the outer layer of the aorta, aortic dissection can be fatal. Usual tensile or inflation tests induce unstable dynamic failures, in which controlled tear propagation cannot be achieved. Therefore, these methods are poorly suited to quantify the fracture properties of soft biological tissue. Several other approaches have been developed instead.
CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Shankar Narayan S., Anuradha Bhattacharjee, Sunanda Saha
The human aorta contains three layers: the inner layer (intima), the middle layer (media), and the outer layer, which can be more than an inch broad in certain locations (adventitia). The aorta can develop issues that endanger the heart and the blood flow to the rest of the body (Witmer 2008; Oomens et al. 2017; Gasser 2017). An aortic aneurysm is a weak spot or bulge on the aorta’s wall that can develop anywhere along the vessel’s length. Two issues can result from aortic aneurysms. A hole, known as a rupture, might form in the weaker or inflated region, allowing blood to leak into the body. The layers of the artery wall can be separated by the blood that is forced through the aorta, enabling blood to accumulate there and further dividing the arterial wall. Aortic dissections occur when the layers of the aorta, which carry blood from the heart, separate. This may result in aortic rupture or reduced blood supply to organs (ischemia).
Flow analysis of aortic dissection: comparison of inflow boundary conditions for computational models based on 4D PCMRI and Doppler ultrasound
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Zhenfeng Li, Shichao Liang, Huanming Xu, Minjia Zhu, Yuqian Mei, Jiang Xiong, Duanduan Chen
Aortic dissection (AD) is a life-threatening cardiovascular disease which has a 80% mortality rate within two weeks (type-A) and 10% or higher mortality rate within 30 days (type-B) (Criado 2011). The weakened inner wall of the aorta develops a tear resulting in the separation of the aortic wall layers into true and false lumens due to the continuous invasion of the blood flow within the aortic wall. This disease may lead to complex complications such as hypotension/shock, end organ ischemia, aortic rupture and ultimately death if left untreated (Tse et al. 2011). AD is classified into Stanford type-A, in which the dissection involves the ascending aorta, and Stanford type-B, where the dissection only affects the descending aorta and the distal region (Daily et al. 1970). In general, type-A dissection is a medical emergency that requires urgent surgical repair; while type-B dissection is less lethal, most of which could be treated by endovascular repair (Doyle and Norman 2016), giving time for modelling-based treatment plan.
Device profile of the Zenith Dissection Endovascular System for aortic dissection
Published in Expert Review of Medical Devices, 2019
Konstantinos Spanos, Tilo Kölbel
Aortic dissection (AD) is defined as the disruption of the media layer of the aorta with bleeding within and along its wall, resulting in separation of the aortic wall layers [1]. Two primary hypotheses of AD pathogenesis have been proposed, either a consequence of the rupture of vasa vasorum in the medial layer of the aortic wall or the outcome after an intimal entry tear, allowing blood from the aortic lumen to enter the aortic wall, resulting in a secondary intimal rupture [1]. The incidence of acute AD ranges from 2 to 3.5 cases per 100,000 person/years based on population-based studies [2,3]. The International Registry of AD (IRAD) reported a mean age of AD presentation at 63 years [4]. Almost half of the patients with AD die immediately (40%), 1% per hour die thereafter, and between 5% and 20% die during or shortly after the intervention [5].