Mechanical wall stress in abdominal aortic aneurysm: Influence of diameter and asymmetry

Vorp, David A.; Raghavan, M.; Webster, Marshall W.

doi:10.1016/s0741-5214(98)70227-7

Cited by 377 publications

(362 citation statements)

References 21 publications

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“…Also, it can lead to an increased rupture risk and aneurysm dilatation with growing systolic and mean pressure after TAVI and the increase in wall stress. 13,14) Likewise, an aneurysm operation in a patient with severe aortic stenosis presents high-risk. Surgical aneurysm repair had a high-risk because of the very severe aortic stenosis in our case as well.…”

Section: Discussionmentioning

confidence: 99%

Simultaneously Successful Transfemoral Aortic Valve Implantation and Endovascular Repair of Thoracic Aortic Saccular Aneurysm

et al. 2014

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SummaryThe prevalence of aortic stenosis (AS) increases in the elderly. They present high surgical risk due to comorbid factors that increase with age. Transcatheter aortic valve implantation (TAVI) is an effective method in patients who present with severe aortic stenosis with a higher surgical risk or who cannot undergo surgical aortic valve replacement (s-AVR). In our case, the presence of saccular thoracic aortic aneurysm with severe AS, which is a vital co-morbidity, requires the treatment of both. The rise in systolic pressure following the TAVI procedure increases the saccular thoracic aneurysm rupture risk and this is why the timing and method of the two treatments become crucial. In this case, which is as far as we know the first and only report in the literature, both TAVI and endovascular thoracic aortic saccular aneurysm repair were applied simultaneously and successfully to the patient via the same transfemoral route. After 1 month, the patient had good functional capacity and there were no complications in control tomography and echocardiography. In this way, we attempted to emphasize with a multidisciplinary study that the patients be assessed carefully before the procedure, and found that even in patients with common peripheral vascular diseases, a transfemoral route could be used together with the proper methods, and that both procedures could be performed simultaneously. (Int Heart J 2014; 55: 459-462) Key words: Transcatheter aortic valve implantation, TEVAR, Aortic aneurysm T he prevalence of aortic stenosis (AS) has increased with the increase in life expectancy. As a result, severe comorbid factors can occur in advanced ages. The surgical replacement of a stenotic aortic valve (s-AVR) can be performed with low operative mortality rates in the absence of serious comorbid conditions. The patients undergoing s-AVR tend to have greater life expectancy and progress in their symptoms. However, 30% of the patients cannot undergo s-AVR due to left ventricular dysfunction, advanced age, and comorbid conditions. 1,2) Performed for the first time on a patient in 2002, transcatheter aortic valve implantation (TAVI) has become the leading treatment option for high risk and inoperable patient groups. One of the comorbid factors that increases the risk in patients is aortic aneurysm. The rupture risk will be increased with the increase in systolic pressure due to the aortic stenosis being treated. Hence, the timing and method of both treatments are of great importance in our high-risk case which was complicated by a thoracic aortic saccular aneurysm and serious aortic stenosis. In this study, thanks to our unique case in the literature, we managed to show that transfemoral aortic valve implantation and endovascular aneurysm repair could be performed simultaneously and successfully using the same femoral route by evaluating them in a detailed multidisciplinary way. Case ReportAn 83 year-old male patient with a history of coronary artery bypass grafting (CABG) and a permanent pacemaker (VVI-R type) follo...

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Section: Discussionmentioning

confidence: 99%

Simultaneously Successful Transfemoral Aortic Valve Implantation and Endovascular Repair of Thoracic Aortic Saccular Aneurysm

et al. 2014

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“…Gijsen et al (1997) suggested a new experimental technique to determine the wall shear stress in vivo. Vorp et al (1998) used a coupled fluid structure interaction model to combine the influence of mechanical stress and wall shear stress and concluded that the arterial diseases are most probably localized in regions of high mechanical stress and low wall shear stress. However, the mechanical stress within the wall cannot easily be extracted unless further development in imaging techniques and image segmentation algorithms are achieved.…”

Section: Article In Pressmentioning

confidence: 99%

“…Although being studied by many authors (e.g. Womersley, 1955;McDonald, 1974;Caro et al, 1978;Ku et al, 1985;Moore et al, 1994a, b;Reneman et al, 1993;Taylor et al, 1996;Gijsen et al, 1997;Vorp et al, 1998;Wootton and Ku, 1999), the relation between flow fields and cardiovascular diseases is still not fully understood, and is currently receiving more and more attention (Botnar et al, 2000;Berthier et al, 2002;Cheng et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Mesoscopic simulations of systolic flow in the human abdominal aorta

Artoli

Hoekstra

Sloot

2006

Journal of Biomechanics

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The complex nature of blood flow in the human arterial system is still gaining more attention, as it has become clear that cardiovascular diseases localize in regions of complex geometry and complex flow fields. In this article, we demonstrate that the lattice Boltzmann method can serve as a mesoscopic computational hemodynamic solver. We argue that it may have benefits over the traditional Navier-Stokes techniques. The accuracy of the method is tested by studying time-dependent systolic flow in a 3D straight rigid tube at typical hemodynamic Reynolds and Womersley numbers as an unsteady flow benchmark. Simulation results of steady and unsteady flow in a model of the human aortic bifurcation reconstructed from magnetic resonance angiography, are presented as a typical hemodynamic application. r

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“…The AAA arises in the infrarenal aorta with a diameter greater than 3 cm and can be up to 9 cm in length [1,2]. Most of the studies on aneurysms have focused on already existing realistic or idealized aneurysms [33][34][35][36][37][38][39][40][41][42][43] with the aim of defining a relevant rupture criterion [4,7,10,19,20,24]. The ratio of the vessel stress to vessel strength is regarded as an alternative tool to conventional diameter criteria, which may be insufficient in small aneurysms.…”

mentioning

confidence: 99%

“…The ratio of the vessel stress to vessel strength is regarded as an alternative tool to conventional diameter criteria, which may be insufficient in small aneurysms. In computational simulations, vessel stress is calculated as a function of the vessel diameter [7,34], wall thickness [36,37], asymmetry [14,18,34,36], tortuosity [21], material property [17,24,29,38], calcification [15,22], intraluminal thrombus (ILT) [5,15,16,33], and blood flow [4, 9, 13, 14, 17, 20, 25, 26, 28-30, 32, 35-41]. Blood vessel strength is measured by ex vivo studies [11,12,23,31,44] or estimated by effective features such as ILT existence, sex, and genetic vulnerability [10].…”

mentioning

confidence: 99%

Investigation of material modeling in fluid–structure interaction analysis of an idealized three-layered abdominal aorta: aneurysm initiation and fully developed aneurysms

Şimşek

Kwon

2015

J Biol Phys

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Different material models for an idealized three-layered abdominal aorta are compared using computational techniques to study aneurysm initiation and fully developed aneurysms. The computational model includes fluid-structure interaction (FSI) between the blood vessel and the blood. In order to model aneurysm initiation, the medial region was degenerated to mimic the medial loss occurring in the inception of an aneurysm. Various cases are considered in order to understand their effects on the initiation of an abdominal aortic aneurysm. The layers of the blood vessel were modeled using either linear elastic materials or Mooney-Rivlin (otherwise known as hyperelastic) type materials. The degenerated medial region was also modeled in either linear elastic or hyperelastic-type materials and assumed to be in the shape of an arc with a thin width or a circular ring with different widths. The blood viscosity effect was also considered in the initiation mechanism. In addition, dynamic analysis of the blood vessel was performed without interaction with the blood flow by applying time-dependent pressure inside the lumen in a three-layered abdominal aorta. The stresses, strains, and displacements were compared for a healthy aorta, an initiated aneurysm and a fully developed aneurysm. The study shows that the material modeling of the vessel has a sizable effect on aneurysm initiation and fully developed aneurysms. Different material modeling of degeneration regions also affects the stressstrain response of aneurysm initiation. Additionally, the structural analysis without considering FSI (called noFSI) overestimates the peak von Mises stress by 52% at the interfaces of the layers.

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Mechanical wall stress in abdominal aortic aneurysm: Influence of diameter and asymmetry

Cited by 377 publications

References 21 publications

Simultaneously Successful Transfemoral Aortic Valve Implantation and Endovascular Repair of Thoracic Aortic Saccular Aneurysm

Simultaneously Successful Transfemoral Aortic Valve Implantation and Endovascular Repair of Thoracic Aortic Saccular Aneurysm

Mesoscopic simulations of systolic flow in the human abdominal aorta

Investigation of material modeling in fluid–structure interaction analysis of an idealized three-layered abdominal aorta: aneurysm initiation and fully developed aneurysms

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