The Effects of Arterial Tissue Reorganization on the Geometrical Outputs of Pressure- and Flow-Induced Remodeling: A Theoretical Study

Arterial remodeling in response to sustained alterations in blood pressure and/or flow induces changes in vessel geometry, structure, and composition. In conditions of hypertension and elevated blood flow, remodeling results in increased vessel mass that is distributed in a manner to maintain the local mechanical environment of the vascular cells at a baseline state. A majority of theoretical studies on remodeling have assumed that new mass is formed via a proportional production of load-bearing constituents, namely elastin, collagen, and smooth muscle. Therefore, when the vascular tissue is considered as a constrained mixture of these structural components, their mass fractions do not change as a result of remodeling. However, increased arterial mass is primarily attributed to smooth muscle cell hypertrophy and upregulated collagen production, implying a change in the mass fractions of all constituents and therefore the tissue mechanical properties [1]. Moreover, few papers account for remodeling-induced changes in the configuration and/or orientation of collagen fibers, both of which may also alter tissue mechanical properties. The objective of this study is to build a mathematical model that enables evaluation of the effects of mass redistribution among structural components and changes in collagen fiber configuration on the geometrical outputs of arterial remodeling.