Mechanical and geometrical determinants of wall stress in abdominal aortic aneurysms: A computational study

• Published in: PloS one 2018-02, Vol.13 (2), p.e0192032-e0192032
• Main Authors: Azar, Dara, Ohadi, Donya, Rachev, Alexander, Eberth, John F, Uline, Mark J, Shazly, Tarek
• Format: Article
• Language: English
• Subjects: Abdomen; Aged; Aneurysms; Aorta; Aortic aneurysm; Aortic Aneurysm, Abdominal - pathology; Aortic aneurysms; Asymmetry; Atherosclerosis; Biology and Life Sciences; Biomechanics; Biomedical engineering; Biophysics; Chemical engineering; Clinical decision making; Complications and side effects; Computation; Computer applications; Computer Simulation; Coronary vessels; Decision making; Engineering schools; Female; Finite Element Analysis; Finite element method; Fluid-structure interaction; Geometry; Growth rate; Humans; Male; Mathematical models; Mechanical properties; Medical research; Medicine and Health Sciences; Morbidity; Patients; Physical Sciences; Physiological aspects; Risk assessment; Rupture; Rupturing; Sensitivity analysis; Series (mathematics); Set theory; Stress; Stress, Physiological; Stresses; Studies; Tomography
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0192032

An aortic aneurysm (AA) is a focal dilatation of the aortic wall. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. The decision to surgically intervene prior to AA rupture is made with recognition of significant procedural risks, and is primarily based on the maximal diameter and/or growth rate of the AA. Despite established thresholds for intervention, rupture occurs in a notable subset of patients exhibiting sub-critical maximal diameters and/or growth rates. Therefore, a pressing need remains to identify better predictors of rupture risk and ultimately integrate their measurement into clinical decision making. In this study, we use a series of finite element-based computational models that represent a range of plausible AA scenarios, and evaluate the relative sensitivity of wall stress to geometrical and mechanical properties of the aneurysmal tissue. Taken together, our findings encourage an expansion of geometrical parameters considered for rupture risk assessment, and provide perspective on the degree to which tissue mechanical properties may modulate peak stress values within aneurysmal tissue.