A Mathematical Model of Maladaptive Inward Eutrophic Remodeling of Muscular Arteries in Hypertension.

We propose a relatively simple two-dimensional mathematical model for maladaptive inward remodeling of resistive arteries in hypertension in terms of vascular solid mechanics. The main premises are: (i) maladaptive inward remodeling manifests as a reduced increase in the arterial mass compared to the case of adaptive remodeling under equivalent hypertensive pressures and (ii) the pressure-induced circumferential stress in the arterial wall is restored to its basal target value as happens in the case of adaptive remodeling. The rationale for these assumptions is the experimental findings that elevated tone in association with sustained hypertensive pressure down-regulate the normal differentiation of vascular smooth muscle cells from contractile to synthetic phenotype and the data for the calculated hoop stress before and after completion of remodeling.

A Two-Dimensional Model of Hypertension-Induced Arterial Remodeling With Account for Stress Interaction Between Elastin and Collagen.

We propose a novel structure-based two-dimensional (2D) mathematical model of hypertension-induced arterial remodeling. The model is built in the framework of the constrained mixture theory and global growth approach, utilizing a recently proposed structure-based constitutive model of arterial tissue that accounts for the individual natural configurations of and stress interaction between elastin and collagen. The basic novel predictive result is that provided remodeling causes a change in the elastin/collagen mass fraction ratio, it leads to a structural reorganization of collagen that manifests as an altered fiber undulation and a change in direction of the helically oriented fibers in the tissue natural state.

A structure-based constitutive model of arterial tissue considering individual natural configurations of elastin and collagen.

The study proposes a novel theoretical-experimental approach for structure-based constitutive modeling of the passive mechanical properties of arterial tissue. The major novelty is accounting for the existence of individual natural configurations of elastin and collagen and their mechanical interaction in terms of the constituents' individual prestretches in the tissue natural state. The structure-based modeling of collagen allows accounting for effects of change in constituents' prestretch in terms of the change in feasible microstructural parameters, such as range of collagen recruitment stretch, mode of collagen mass fraction intensity function, and fiber directions.

Mechanical and geometrical determinants of wall stress in abdominal aortic aneurysms: A computational study.

An aortic aneurysm (AA) is a focal dilatation of the aortic wall. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. The decision to surgically intervene prior to AA rupture is made with recognition of significant procedural risks, and is primarily based on the maximal diameter and/or growth rate of the AA.

The perivascular environment along the vertebral artery governs segment-specific structural and mechanical properties.

Unlabelled: The vertebral arteries (VAs) are anatomically divided into four segments (V-V), which cumulatively transport blood flow through neck and ultimately form the posterior circulation of the brain. The vital physiological function of these conduit vessels depends on their geometry, composition and mechanical properties, all of which may vary among the defined arterial segments. Despite their significant role in blood circulation and susceptibility to injury, few studies have focused on characterizing the mechanical properties of VAs, and none have investigated the potential for segmental variation that could arise due to distinct perivascular environments.