An Animal-Specific FSI Model of the Abdominal Aorta in Anesthetized Mice
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Recent research has revealed that angiotensin II-induced abdominal aortic aneurysm in mice can be related to medial ruptures occurring in the vicinity of abdominal side branches. Nevertheless a thorough understanding of the biomechanics near abdominal side branches in mice is lacking. In the current work we present a mouse-specific fluid–structure interaction (FSI) model of the abdominal aorta in ApoE−/− mice that incorporates in vivo stresses. The aortic geometry was based on contrast-enhanced in vivo micro-CT images, while aortic flow boundary conditions and material model parameters were based on in vivo high-frequency ultrasound. Flow waveforms predicted by FSI simulations corresponded better to in vivo measurements than those from CFD simulations. Peak-systolic principal stresses at the inner and outer aortic wall were locally increased caudal to the celiac and left lateral to the celiac and mesenteric arteries. Interestingly, these were also the locations at which a tear in the tunica media had been observed in previous work on angiotensin II-infused mice. Our preliminary results therefore suggest that local biomechanics play an important role in the pathophysiology of branch-related ruptures in angiotensin-II infused mice. More elaborate follow-up research is needed to demonstrate the role of biomechanics and mechanobiology in a longitudinal setting.
KeywordsFluid–structure interaction Computational fluid dynamics Abdominal aorta Mouse model Mouse-specific High-frequency ultrasound Micro-CT Abdominal aortic aneurysm Dissecting aneurysm
This research was funded by the Special Research Fund of Ghent University under Grant [BOF10/GOA/005] and by internal funds of the Laboratory of Hemodynamics and Cardiovascular Technology, EPFL. B.T. received a travel grant of the Flemish Fund for Scientific Research. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by Ghent University, the Hercules Foundation and the Flemish Government—department EWI.
Conflict of interest
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