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Finite element analysis of mechanics of neovessels with intraplaque hemorrhage in carotid atherosclerosis.

Lu J, Duan W, Qiao A - Biomed Eng Online (2015)

Bottom Line: Different mechanical boundary conditions, i.e. static pressures, were imposed in the carotid lumen and neovessels lumen respectively.With the same distance to the carotid lumen, the longer the perimeter of neovessels is, the larger stress and the deformation of the neovessels will be.Local mechanical conditions may result in the hemorrhage of neovessels and accelerate the rupture of plaque.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Intraplaque hemorrhage is a widely known factor facilitating plaque instability. Neovascularization of plaque can be regarded as a compensatory response to the blood supply in the deep intimal and medial areas of the artery. Due to the physiological function, the deformation of carotid atherosclerotic plaque would happen under the action of blood pressure and blood flow. Neovessels are subject to mechanical loading and likely undergo deformation. The rupture of neovessels may deteriorate the instability of plaque. This study focuses on the local mechanical environments around neovessels and investigates the relationship between the biomechanics and the morphological specificity of neovessels.

Methods: Stress and stretch were used to evaluate the rupture risk of the neovessels in plaque. Computational structural analysis was performed based on two human carotid plaque slice samples. Two-dimensional models containing neovessels and other components were built according to the plaque slice samples. Each component was assumed to be non-linear isotropic, piecewise homogeneous and incompressible. Different mechanical boundary conditions, i.e. static pressures, were imposed in the carotid lumen and neovessels lumen respectively. Finite element method was used to simulate the mechanical conditions in the atherosclerotic plaque.

Results: Those neovessels closer to the carotid lumen undergo larger stress and stretch. With the same distance to the carotid lumen, the longer the perimeter of neovessels is, the larger stress and the deformation of the neovessels will be. Under the same conditions, the neovessels with larger curvature suffer greater stress and stretch. Neovessels surrounded by red blood cells undergo a much larger stretch.

Conclusions: Local mechanical conditions may result in the hemorrhage of neovessels and accelerate the rupture of plaque. The mechanical environments of the neovessel are related to its shape, curvature, distance to the carotid lumen and the material properties of plaque.

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Related in: MedlinePlus

The relationship between critical mechanical conditions around the neovessels and their distance from the main arterial lumen. (a) local maximum principal stress (Stress-P1) at systole when neovessels without red blood cells surrounded; (b) local maximum principal stretch (Stretch-P1) at systole when neovessels without red blood cells surrounded; (c) local maximum principal stress (Stress-P1) at systole when neovessels with red blood cells surrounded; (d) local maximum principal stretch (Stretch-P1) at systole when neovessels with red blood cells surrounded.
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Figure 3: The relationship between critical mechanical conditions around the neovessels and their distance from the main arterial lumen. (a) local maximum principal stress (Stress-P1) at systole when neovessels without red blood cells surrounded; (b) local maximum principal stretch (Stretch-P1) at systole when neovessels without red blood cells surrounded; (c) local maximum principal stress (Stress-P1) at systole when neovessels with red blood cells surrounded; (d) local maximum principal stretch (Stretch-P1) at systole when neovessels with red blood cells surrounded.

Mentions: According to the distance to the lumen of the neovessels, the mechanical situations of neovessels are particularly considered. The analysis of the mechanical conditions of neovessels in plaque will be demonstrated. Two groups of neovessels with similar curvature and similar perimeter are randomly selected. The relationships between the local maximum principal stress Stress-P1 and the local maximum principal stretch Stretch-P1 with the various distances to lumen of each neovessel are shown in Figure 3.


Finite element analysis of mechanics of neovessels with intraplaque hemorrhage in carotid atherosclerosis.

Lu J, Duan W, Qiao A - Biomed Eng Online (2015)

The relationship between critical mechanical conditions around the neovessels and their distance from the main arterial lumen. (a) local maximum principal stress (Stress-P1) at systole when neovessels without red blood cells surrounded; (b) local maximum principal stretch (Stretch-P1) at systole when neovessels without red blood cells surrounded; (c) local maximum principal stress (Stress-P1) at systole when neovessels with red blood cells surrounded; (d) local maximum principal stretch (Stretch-P1) at systole when neovessels with red blood cells surrounded.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4306113&req=5

Figure 3: The relationship between critical mechanical conditions around the neovessels and their distance from the main arterial lumen. (a) local maximum principal stress (Stress-P1) at systole when neovessels without red blood cells surrounded; (b) local maximum principal stretch (Stretch-P1) at systole when neovessels without red blood cells surrounded; (c) local maximum principal stress (Stress-P1) at systole when neovessels with red blood cells surrounded; (d) local maximum principal stretch (Stretch-P1) at systole when neovessels with red blood cells surrounded.
Mentions: According to the distance to the lumen of the neovessels, the mechanical situations of neovessels are particularly considered. The analysis of the mechanical conditions of neovessels in plaque will be demonstrated. Two groups of neovessels with similar curvature and similar perimeter are randomly selected. The relationships between the local maximum principal stress Stress-P1 and the local maximum principal stretch Stretch-P1 with the various distances to lumen of each neovessel are shown in Figure 3.

Bottom Line: Different mechanical boundary conditions, i.e. static pressures, were imposed in the carotid lumen and neovessels lumen respectively.With the same distance to the carotid lumen, the longer the perimeter of neovessels is, the larger stress and the deformation of the neovessels will be.Local mechanical conditions may result in the hemorrhage of neovessels and accelerate the rupture of plaque.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Intraplaque hemorrhage is a widely known factor facilitating plaque instability. Neovascularization of plaque can be regarded as a compensatory response to the blood supply in the deep intimal and medial areas of the artery. Due to the physiological function, the deformation of carotid atherosclerotic plaque would happen under the action of blood pressure and blood flow. Neovessels are subject to mechanical loading and likely undergo deformation. The rupture of neovessels may deteriorate the instability of plaque. This study focuses on the local mechanical environments around neovessels and investigates the relationship between the biomechanics and the morphological specificity of neovessels.

Methods: Stress and stretch were used to evaluate the rupture risk of the neovessels in plaque. Computational structural analysis was performed based on two human carotid plaque slice samples. Two-dimensional models containing neovessels and other components were built according to the plaque slice samples. Each component was assumed to be non-linear isotropic, piecewise homogeneous and incompressible. Different mechanical boundary conditions, i.e. static pressures, were imposed in the carotid lumen and neovessels lumen respectively. Finite element method was used to simulate the mechanical conditions in the atherosclerotic plaque.

Results: Those neovessels closer to the carotid lumen undergo larger stress and stretch. With the same distance to the carotid lumen, the longer the perimeter of neovessels is, the larger stress and the deformation of the neovessels will be. Under the same conditions, the neovessels with larger curvature suffer greater stress and stretch. Neovessels surrounded by red blood cells undergo a much larger stretch.

Conclusions: Local mechanical conditions may result in the hemorrhage of neovessels and accelerate the rupture of plaque. The mechanical environments of the neovessel are related to its shape, curvature, distance to the carotid lumen and the material properties of plaque.

Show MeSH
Related in: MedlinePlus