Towards an understanding of the mechanics underlying aortic dissection

Abstract

Acute aortic dissection and associated aortic catastrophes are among the most devastating forms of cardiovascular disease, with a remarkably high morbidity and mortality despite current medical and surgical treatment. The mechanics underlying aortic dissection are incompletely understood, and a further understanding of the relevant fluid and solid mechanics may yield not only a better appreciation of its pathogenesis, but also the development of improved diagnostic and therapeutic strategies. After illustrating some of the inadequacies with respect to the extant work on the mechanics of aortic dissection, we alternatively postulate that the clinical hemodynamic disturbances that render the aorta susceptible to the initiation of dissection are principally elevated maximum systolic and mean aortic blood pressure, whereas the hemodynamic disturbances that facilitate propagation of dissection are principally elevated pulse pressure and heart rate. Furthermore, abnormal aortic mechanical properties and/or geometry are requisite for dissection to occur. Specifically, we propose that the degree of anisotropy will directly influence the probability of future aortic dissection. Imaging of the aorta may provide information regarding aortic anisotropy and geometry, and in combination with a hemodynamic risk assessment, has the potential to be able to prospectively identify patients at high risk for future aortic dissection thereby facilitating prophylactic intervention. The aim of the paper is to identify the main mechanical issues that have a bearing on aortic dissection, and to suggest an appropriate mathematical model for describing the problem.

Differential distribution of structural components and hydration in aortic and pulmonary heart valve conduits: Impact of detergent-based cell removal

“…The former is considered to be congenital, while in the second case why such an intimal tear should often occur in the absence of any connective tissue or local disease is not always clear. In a recent report factors in the initiation and propagation of rupture have been related to the inhomogeneity and anisotropy of the aorta, which locally determine the stresses [63]. Accordingly, we speculate that the asymmetric higher concentration of elastin in the ascending aorta might also be considered a structural inhomogeneity of the wall, despite being related to local functional requirements, and should very probably be taken into account when investigating the rationale behind the onset of the primary tear in acute aortic syndrome.…”

Efeitos da remoção da túnica adventícia da aorta descendente em suínos

“…There are several factors to be considered, such as hemodynamic disorders and factors related to the mechanical and geometrical properties of the aorta (anisotropy and the structural organization of the aortic wall) 1 .…”

“…There are several factors to be considered, such as hemodynamic disorders and factors related to mechanical and geometrical properties of the aorta 1 . The Vasa Vasorum (VV) have an important role in various diseases, as insufficient blood flow through the aortic wall is involved in the pathophysiology of atherosclerosis and may contribute to necrosis of the aortic tunica media.…”

Computational Biomechanics in Thoracic Aortic Dissection: Today’s Approaches and Tomorrow’s Opportunities

“…Subsequent propagation of the dissection is thought to be influenced by pulse pressure and cycle frequency. 70 The most common symptom of AoD is severe acute chest and thoracic back pain. This may be associated with either hypertension, or in the event of aortic rupture, hypotension.…”