Abstract

Intracranial aneurysms (ICAs) are focal dilatations that imply a weakening of the brain artery. Incidental rupture of an ICA is increasingly responsible for significant mortality and morbidity in the American’s aging population. Previous studies have quantified the pressure-volume characteristics, uniaxial mechanical properties, and morphological features of human aneurysms. In this pilot study, for the first time, we comprehensively quantified the mechanical, collagen fiber microstructural, and morphological properties of one resected human posterior inferior cerebellar artery aneurysm. The tissue from the dome of a right posterior inferior cerebral aneurysm was first mechanically characterized using biaxial tension and stress relaxation tests. Then, the load-dependent collagen fiber architecture of the aneurysm tissue was quantified using an in-house polarized spatial frequency domain imaging system. Finally, optical coherence tomography and histological procedures were used to quantify the tissue’s microstructural morphology. Mechanically, the tissue was shown to exhibit hysteresis, a nonlinear stress-strain response, and material anisotropy. Moreover, the unloaded collagen fiber architecture of the tissue was predominantly aligned with the testing Y-direction and rotated towards the X-direction under increasing equibiaxial loading. Furthermore, our histological analysis showed a considerable damage to the morphological integrity of the tissue, including lack of elastin, intimal thickening, and calcium deposition. This new unified characterization framework can be extended to better understand the mechanics-microstructure interrelationship of aneurysm tissues at different time points of the formation or growth. Such specimen-specific information is anticipated to provide valuable insight that may improve our current understanding of aneurysm growth and rupture potential.

Details

Title
A pilot study on biaxial mechanical, collagen microstructural, and morphological characterizations of a resected human intracranial aneurysm tissue
Author
Laurence, Devin W 1 ; Homburg, Hannah 2 ; Feng, Yan 3 ; Tang Qinggong 3 ; Kar-Ming, Fung 4 ; Bohnstedt, Bradley N 5 ; Holzapfel, Gerhard A 6 ; Chung-Hao, Lee 7 

 The University of Oklahoma, Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, Norman, USA (GRID:grid.266900.b) (ISNI:0000 0004 0447 0018) 
 The University of Oklahoma Health Sciences Center, Department of Neurosurgery, Oklahoma City, USA (GRID:grid.266902.9) (ISNI:0000 0001 2179 3618) 
 The University of Oklahoma, Biophotonic Imaging Laboratory, Stephenson School of Biomedical Engineering, Norman, USA (GRID:grid.266900.b) (ISNI:0000 0004 0447 0018) 
 The University of Oklahoma Health Sciences Center, Department of Pathology, Oklahoma City, USA (GRID:grid.266902.9) (ISNI:0000 0001 2179 3618); The University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Oklahoma City, USA (GRID:grid.266902.9) (ISNI:0000 0001 2179 3618) 
 Indiana University School of Medicine, Department of Neurological Surgery, Indianapolis, USA (GRID:grid.257413.6) (ISNI:0000 0001 2287 3919) 
 Graz University of Technology, Institute of Biomechanics, Graz, Austria (GRID:grid.410413.3) (ISNI:0000 0001 2294 748X); Norwegian University of Science and Technology, Department of Structural Engineering, Trondheim, Norway (GRID:grid.5947.f) (ISNI:0000 0001 1516 2393) 
 The University of Oklahoma, Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, Norman, USA (GRID:grid.266900.b) (ISNI:0000 0004 0447 0018); The University of Oklahoma, Institute for Biomedical Engineering, Science and Technology, Norman, USA (GRID:grid.266900.b) (ISNI:0000 0004 0447 0018) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2488040650
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.