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Coupled hemodynamics and mechanics of the repaired human carotid artery
Restenosis is a major complication of the existing surgical techniques used to treat atherosclerosis of the carotid artery. Recently, atherosclerosis has been linked to certain mechanical factors. The objective of this work was to develop a comprehensive model of a reconstructed human carotid and to use it to study relevant mechanical characteristics as functions of repair technique and material.^ Three-dimensional geometry of the blood vessel was constructed using computerized tomography data. The observed geometry was more tortuous and with less bifurcation angle than it had been commonly assumed before. Mechanical properties of the carotid artery wall and common repair materials were evaluated by biaxial mechanical testing. It was found that the behavior of tissues is highly non-linear and anisotropic. All tested patching materials were substantially stiffer than the carotid walls. Hemodynamics of the blood flow at the boundaries of the carotid artery was studied using duplex ultrasound method. It was found that velocity profiles in the carotid artery are not symmetric. A comprehensive finite element model of a patched carotid was developed that takes into account the interaction between the blood flow and the arterial wall, non-linear anisotropic mechanical properties of the wall, complex three-dimensional vessel geometry, real pulsatile blood velocity profiles, non-Newtonian blood rheology, and closure with suture. ^ Analysis of the results of modeling showed that certain techniques and materials have advantages and some have shortcomings. It was found that increase in the patch width had negative effect on the behavior of the artery. Lateral placement of the patch decreased stresses in the arterial wall but at the same time broadened the low wall shear stress region and boosted the cyclic strain. Patch material had significant effect on behavior of the repaired artery. Overall, analysis of the existing repair techniques showed that the ideal patch and/or repair method are yet to be found. The developed model can be used to study and optimize the results of surgical interventions and can help develop improved repair techniques and materials.^
Engineering, Mechanical|Biophysics, Biomechanics
Kamenskiy, Alexey, "Coupled hemodynamics and mechanics of the repaired human carotid artery" (2009). ETD collection for University of Nebraska - Lincoln. AAI3386755.