A previous study that assessed ruptured and non-ruptured AA via computed values of the peak wall stress (PWS) demonstrated that incorporation of various levels of geometric complexity derived from computed tomography data could significantly impact obtained results. The results of any FEA-based study are highly dependent on the employed material models and distinct domains in which wall stress is computed. Other studies have also suggested that indices of AA surface curvature and wall thickness impact rupture risk, primarily via correlation of rupture location with geometrical features of the AA. Previous studies have shown that, in addition to maximum AA diameter, centerline tortuosity is a deterministic parameter in AA rupture risk. Therefore, any advancement in terms of assessing the risk of AA rupture would be of high clinical significance.Ĭomputational modeling utilizing finite element analysis (FEA) is a well-established approach to predict wall stresses in the context of AA. Endovascular or surgical repair of AA is not without significant costs and complications. Despite the multiple determinants of wall stress, a set-point point of 5.0–5.5 cm in diameter is the typical threshold for surgical intervention. Intramural stresses generally increase with aneurysm growth and inherently depend on the applied loads, the geometry and location of the AA, and the mechanical properties of the aortic wall. While stimuli for AA genesis and progression can be diverse, wall rupture is ultimately a mechanical failure that occurs when intramural stresses exceed wall strength. Thus, several million patients carry the diagnosis of AA, and unfortunately a significant portion of these patients will either die from rupture or morbidity arising from complex surgical/endovascular repairs. AA can arise in either the thoracic or abdominal sections, with current estimates that over a quarter-million new cases of AA occur each year in the United States alone. Diagnosed using ultrasonography, computed tomography, or magnetic resonance imaging, a segment of the aorta that is found to be greater than 50% larger than that of a healthy individual of the same sex and age is considered aneurysmal. 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.Ī significant manifestation of cardiovascular disease involves a regional dilation of the aorta termed an aortic aneurysm (AA).
#Postview principal curvature series#
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. Therefore, a pressing need remains to identify better predictors of rupture risk and ultimately integrate their measurement into clinical decision making. Despite established thresholds for intervention, rupture occurs in a notable subset of patients exhibiting sub-critical maximal diameters and/or growth rates. 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. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. An aortic aneurysm (AA) is a focal dilatation of the aortic wall.
0 kommentar(er)
