Geometry of the Carotid Artery and Its Association With Pathologic Changes in a Chinese Population

Figures

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  FIGURE 1. Definition of geometric parameters. (A) Schematic representation of geometric parameters, including carotid bifurcation angle, internal carotid angle, and related laminar shear stress, angle of the internal carotid angle with respect to the common carotid artery, hereafter termed “internal carotid angle.” (B) Computed tomography angiography (CTA) image illustrating the method of measuring carotid bifurcation angle and internal carotid angle (red line). (C) CTA image illustrating measurement of carotid bifurcation angle height relative to the cervical spine. (D) Ultrasonography illustrating measurement of blood flow rate and the diameter of the blood vessels.

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  FIGURE 2. Carotid bifurcation, internal carotid angle, and laminar shear stress in asymptomatic and symptomatic groups. (A) Comparison of carotid bifurcation angle and internal carotid angle. (B) Comparison of laminar shear stress. (C) Correlation of carotid bifurcation angle and internal carotid angle, interaction between asymptomatic and symptomatic groups. (D) Correlation of carotid bifurcation angle and laminar shear stress, interaction between asymptomatic and symptomatic groups. (E) Correlation of internal carotid angle and laminar shear stress, interaction between asymptomatic and symptomatic groups. Error bars represent standard error of mean (SEM). ∗P < 0.05, ∗∗∗P < 0.001.

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  FIGURE 3. Morphometric analysis data for HE and Movat staining. (A) Representative HE and Movat-stained sections of carotid atherosclerotic plaque in asymptomatic and symptomatic groups (bar = 200 μm). (B) Average fibrous cap thickness and narrowest thickness of fibrous cap thickness in asymptomatic and symptomatic groups. (C) Quantification of collagen and proteoglycan in both groups. Error bars represent standard error of mean (SEM). ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001.

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  FIGURE 4. Correlation between carotid bifurcation angle and plaque pathology. (A) Linear regression model of fibrous cap thickness and carotid bifurcation angle (asymptomatic: P < 0.001, R2 = 0.48; symptomatic: P < 0.001, R2 = 0.42); interaction between two groups had statistical significance (P < 0.01). (B) Linear regression model of narrowest thickness of fibrous cap and carotid bifurcation angle (asymptomatic: P < 0.001, R2 = 0.57; symptomatic: P < 0.001, R2 = 0.61); interaction between two groups had statistical significance (P < 0.01). (C) Linear regression model of collagen and carotid bifurcation angle (asymptomatic: P < 0.001, R2 = 0.11; symptomatic: P < 0.001, R2 = 0.07); interaction between two groups had no statistical significance (P = 0.09). (D) Linear regression model of proteoglycan and carotid bifurcation angle (asymptomatic: P > 0.05; symptomatic P < 0.001, R2 = 0.16); interaction between two groups had statistical significance (P < 0.01).

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  FIGURE 5. Correlation between internal carotid angle and plaque pathology. (A) Linear regression model of fibrous cap thickness and internal carotid angle (asymptomatic: P < 0.001, R2 = 0.18; symptomatic: P < 0.001, R2 = 0.44); interaction between two groups had statistical significance (P < 0.001). (B) Linear regression model of narrowest thickness of fibrous cap and internal carotid angle (asymptomatic: P < 0.001, R2 = 0.18; symptomatic: P < 0.001, R2 = 0.58); interaction between two groups had statistical significance (P < 0.001). (C) Linear regression model of thickness of collagen and internal carotid angle (asymptomatic: P > 0.05; symptomatic: P < 0.001, R2 = 0.08); interaction between two groups had no statistical significance (P = 0.15). (D) Linear regression model of proteoglycan and internal carotid angle (asymptomatic: P > 0.05; symptomatic: P < 0.01, R2 = 0.15); interaction between two groups had statistical significance (P < 0.001).

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  FIGURE 6. Correlation between laminar shear stress and plaque pathology. (A) Linear regression model of fibrous cap thickness and laminar shear stress (asymptomatic: P < 0.001, R2 = 0.51; symptomatic: P < 0.001, R2 = 0.29); interaction between two groups had statistical significance (P < 0.01). (B) Linear regression model of narrowest thickness of fibrous cap and laminar shear stress (asymptomatic: P < 0.001, R2 = 0.51; symptomatic: P < 0.001, R2 = 0.50); interaction between two groups had statistical significance (P < 0.001). (C) Linear regression model of collagen and laminar shear stress (asymptomatic: P < 0.001, R2 = 0.14; symptomatic: P > 0.05); interaction between two groups had no statistical significance (P = 0.15). (D) Linear regression model of proteoglycan and laminar shear stress (asymptomatic: P > 0.05; symptomatic: P < 0.01, R2 = 0.14); interaction between two groups had statistical significance (P < 0.001).

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  FIGURE 7. Immunohistochemical staining of YAP in carotid atherosclerotic plaque. (A) Representative immunochemical results of yes-associated protein (YAP) expression in asymptomatic patients and symptomatic patients (bar = 100 μm). (B) Quantification of IOD of YAP in asymptomatic patients and symptomatic patients. Error bars represent standard error of mean (SEM). ∗∗∗P < 0.001. (C) Linear regression model of carotid bifurcation angle and YAP expression (asymptomatic: P > 0.05; symptomatic: P < 0.001, R2 = 0.68); interaction between two groups had statistical significance (P < 0.05). (D) Linear regression model of internal carotid angle and YAP expression (asymptomatic: P > 0.05; symptomatic: P < 0.001, R2 = 0.74); interaction between two groups had statistical significance (P < 0.05). (E) Linear regression model of laminar shear stress and YAP expression (asymptomatic: P > 0.05; symptomatic: P > 0.05); interaction between two groups had statistical significance (P < 0.001).