Aortic Dissection is Determined by Specific Shape and Hemodynamic Interactions

• Published in: Annals of biomedical engineering Vol. 50; no. 12; pp. 1771 - 1786
• Main Authors: Williams, Jessica G., Marlevi, David, Bruse, Jan L., Nezami, Farhad R., Moradi, Hamed, Fortunato, Ronald N., Maiti, Spandan, Billaud, Marie, Edelman, Elazer R., Gleason, Thomas G.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-12-2022; Springer Nature B.V
• Subjects: Angiography; Aorta; Aorta, Thoracic - diagnostic imaging; Aortic aneurysms; Aortic arch; Aortic dissection; Aortic Dissection - diagnostic imaging; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Classical Mechanics; Computational fluid dynamics; Computed tomography; Computer applications; Diameters; Discriminant analysis; Dissection; Feature extraction; Fluid dynamics; Hemodynamics; Humans; Hydrodynamics; Medicin och hälsovetenskap; Original Article; Principal components analysis; Risk assessment; Shear stress; Statistical analysis; Thorax; Tortuosity; Wall shear stresses; Statistical shape analysis; Type A aortic dissection; Aortic aneurysm
• ISSN: 0090-6964; 1573-9686; 1573-9686
• DOI: 10.1007/s10439-022-02979-0

The aim of this study was to determine whether specific three-dimensional aortic shape features, extracted
via
statistical shape analysis (SSA), correlate with the development of thoracic ascending aortic dissection (TAAD) risk and associated aortic hemodynamics. Thirty-one patients followed prospectively with ascending thoracic aortic aneurysm (ATAA), who either did (12 patients) or did not (19 patients) develop TAAD, were included in the study, with aortic arch geometries extracted from computed tomographic angiography (CTA) imaging. Arch geometries were analyzed with SSA, and unsupervised and supervised (linked to dissection outcome) shape features were extracted with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), respectively. We determined PLS-DA to be effective at separating dissection and no-dissection patients (
p
=
0.0010
), with decreased tortuosity and more equal ascending and descending aortic diameters associated with higher dissection risk. In contrast, neither PCA nor traditional morphometric parameters (maximum diameter, tortuosity, or arch volume) were effective at separating dissection and no-dissection patients. The arch shapes associated with higher dissection probability were supported with hemodynamic insight. Computational fluid dynamics (CFD) simulations revealed a correlation between the PLS-DA shape features and wall shear stress (WSS), with higher maximum WSS in the ascending aorta associated with increased risk of dissection occurrence. Our work highlights the potential importance of incorporating higher dimensional geometric assessment of aortic arch anatomy in TAAD risk assessment, and in considering the interdependent influences of arch shape and hemodynamics as mechanistic contributors to TAAD occurrence.