P.08 Biomechanical Characterization of Ascending Thoracic Aortic Aneurysms in Humans: A Continuum Approach to in vivo Deformations
- 10.2991/artres.k.201209.022How to use a DOI?
- Aneurysm; in vivo; characterisation
Background: Dysfunctional cellular mechanosensing appears central to aneurysm formation . We aimed to derive material parameters of aneurysm tissue from in vivo deformations, which may increase insight into the underlying structural integrity of the pathological tissue.
Methods: Videos of tracking markers (example Video in supplement, screenshot in Figure) placed on ascending aortic segments were captured alongside radial arterial blood pressure in patients undergoing open-thorax ascending thoracic aorta aneurysm (ATAA) repair (n = 5) and coronary bypass (controls; n = 2). Normalised cross-correlation was used to determine marker displacements, resulting in estimates of systolic/diastolic diameters, distensibility, and cyclic axial engineering strain. A thin-walled, cylindrical geometry was assumed, with amorphous (Neo-Hookean) and fibrous (two-family) constitutive contributions . This framework was fitted to individual patient measurements, by varying parameters c (amorphous material constant), k1 and k2 (fiber stiffness and strain stiffening parameter), β (fiber angle w.r.t. circumferential direction), unloaded intact length (L), and internal radius (Ri).
Results: Axial strain tended to be lower (expected) and distensibility larger (unexpected) in aneurysm than controls (Figure). However, the intrinsic pressure-dependence of distensibility must be considered when drawing conclusions related to differences in structural stiffness between both groups . Material stiffness parameters (c and k1) appeared higher in aneurysm patients than in controls which is in line with previous studies in mice .
Conclusion: We are developing a method to determine ATAA material properties from in vivo deformations and observed increased material stiffness in ATAA.
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- This is an open access article distributed under the CC BY-NC 4.0 license (http://creativecommons.org/licenses/by-nc/4.0/).
Cite this article
TY - JOUR AU - Shaiv Parikh AU - Bart Spronck AU - Gijs Debeij AU - Berta Ganizada AU - Mitch Ramaekers AU - Simon Schalla AU - Ehsan Natour AU - Jos Maessen AU - Tammo Delhaas AU - Wouter Huberts AU - Elham Bidar AU - Koen Reesink PY - 2020 DA - 2020/12/31 TI - P.08 Biomechanical Characterization of Ascending Thoracic Aortic Aneurysms in Humans: A Continuum Approach to in vivo Deformations JO - Artery Research SP - S28 EP - S29 VL - 26 IS - Supplement 1 SN - 1876-4401 UR - https://doi.org/10.2991/artres.k.201209.022 DO - 10.2991/artres.k.201209.022 ID - Parikh2020 ER -