Thrombus within an aortic aneurysm does not reduce pressure on the aneurysmal wall.
ABSTRACT The role of thrombus within an aneurysm in relation to the risk of rupture is controversial. In literature, reports describing reduction and increase of rupture risk can be found. In the era of endovascular treatment of abdominal aortic aneurysms, a possible reduction of risk of rupture by the presence of thrombus within the aneurysmal sac can be important in relation to the location of an endoleak to the aneurysmal wall and in relation to the effect of the thrombosis of the endoleak, either spontaneously or by intervention.
In nine patients who underwent operation for an infrarenal aortic aneurysm by open procedure at the level of the thickest thrombus lining, the pressure within the aneurysmal thrombus (just inside the aneurysmal wall) was measured and compared with the systemic pressure.
Pressure within systemic circulation and aneurysmal thrombus correlated well for the mean pressure (r = 0.90; P <.001) and for pulse pressure (r = 0.74; P <.01) Also, there was agreement between the levels of the mean pressure. Conduction of mean and pulse pressure to the aneurysmal wall was not related to the thickness of the thrombus at the level of the pressure measurement (r = 0.18 and r = 0.08, respectively).
We conclude that thrombus within the aneurysm does not reduce both the mean and the pulse pressure near the aneurysmal wall and thus will not reduce the risk of rupture of the aneurysm.
Article: Biomechanical aspects of Abdominal Aortic Aneurysm (AAA): Fluid Structure Interaction (FSI) studies of AAA behaviorBiomechanics and Mechanobiology of Aneurysms, Ed. McLoughlin, T., "Studies in Mechanobiology, Tissue Engineering and Biomaterials" (Series Editor: Prof. Amit Gefen) Verlag. 01/2011;
Article: Diagnosis and monitoring of abdominal aortic aneurysm: current status and future prospects.[show abstract] [hide abstract]
ABSTRACT: Abdominal aortic aneurysm (AAA) remains an important cause of morbidity and mortality in elderly men, and prevalence is predicted to increase in parallel with a global aging population. AAA is commonly asymptomatic, and in the absence of routine screening, diagnosis is usually incidental when imaging to assess unrelated medical complaints. In the absence of approved diagnostic and prognostic markers, AAAs are monitored conservatively via medical imaging until aortic diameter approaches 50-55 mm and surgical repair is performed. There is currently significant interest in identifying molecular markers of diagnostic and prognostic value for AAA. Here we outline the current guidelines for AAA management and discuss modern scientific techniques currently employed to identify improved diagnostic and prognostic markers.Current problems in cardiology 10/2010; 35(10):512-48. · 3.96 Impact Factor
Article: Review: the role of biomechanical modeling in the rupture risk assessment for abdominal aortic aneurysms.[show abstract] [hide abstract]
ABSTRACT: AAA disease is a serious condition and a multidisciplinary approach including biomechanics is needed to better understand and more effectively treat this disease. A rupture risk assessment is central to the management of AAA patients, and biomechanical simulation is a powerful tool to assist clinical decisions. Central to such a simulation approach is a need for robust and physiologically relevant models. Vascular tissue senses and responds actively to changes in its mechanical environment, a crucial tissue property that might also improve the biomechanical AAA rupture risk assessment. Specifically, constitutive modeling should not only focus on the (passive) interaction of structural components within the vascular wall, but also how cells dynamically maintain such a structure. In this article, after specifying the objectives of an AAA rupture risk assessment, the histology and mechanical properties of AAA tissue, with emphasis on the wall, are reviewed. Then a histomechanical constitutive description of the AAA wall is introduced that specifically accounts for collagen turnover. A test case simulation clearly emphasizes the need for constitutive descriptions that remodels with respect to the mechanical loading state. Finally, remarks regarding modeling of realistic clinical problems and possible future trends conclude the article.Journal of Biomechanical Engineering 02/2013; 135(2):021010. · 1.90 Impact Factor