Structural parameters defining distribution of collagen fiber directions in human carotid arteries

Structural parameters defining distribution of collagen fiber directions in human carotid arteries

Článek WoS

Collagen fiber arrangement is decisive for constitutive description of anisotropic mechanical response of arterial wall. In this study, their orientation in human common carotid artery was investigated using polarized light microscopy and an automated algorithm giving more than 4 sdot; 10 6 fiber angles per slice. In total 113 slices acquired from 18 arteries taken from 14 cadavers were used for fiber orientation in the circumferential-axial plane. All histograms were approximated with unimodal von Mises distribution to evaluate dominant direction of fibers and their concentration parameter. 10 specimens were analyzed also in circumferential-radial and axial -radial planes (2-4 slices per specimen in each plane); the portion of radially oriented fibers was found insignificant. In the circumferential-axial plane, most specimens showed a pronounced unimodal distribution with angle to circumferential direction mu = 0.7 degrees +/- 9.4 degrees and concentration parameter b = 3.4 +/- 1.9. Suitability of the unimodal fit was confirmed by high values of coefficient of determination (mean R 2 = 0.97, median R 2 = 0.99). Differences between media and adventitia layers were not found statistically significant. The results are directly applicable as structural parameters in the GOH constitutive model of arterial wall if the postulated two fiber families are unified into one with circumferential orientation.

Collagen fiber arrangement is decisive for constitutive description of anisotropic mechanical response of arterial wall. In this study, their orientation in human common carotid artery was investigated using polarized light microscopy and an automated algorithm giving more than 4 sdot; 10 6 fiber angles per slice. In total 113 slices acquired from 18 arteries taken from 14 cadavers were used for fiber orientation in the circumferential-axial plane. All histograms were approximated with unimodal von Mises distribution to evaluate dominant direction of fibers and their concentration parameter. 10 specimens were analyzed also in circumferential-radial and axial -radial planes (2-4 slices per specimen in each plane); the portion of radially oriented fibers was found insignificant. In the circumferential-axial plane, most specimens showed a pronounced unimodal distribution with angle to circumferential direction mu = 0.7 degrees +/- 9.4 degrees and concentration parameter b = 3.4 +/- 1.9. Suitability of the unimodal fit was confirmed by high values of coefficient of determination (mean R 2 = 0.97, median R 2 = 0.99). Differences between media and adventitia layers were not found statistically significant. The results are directly applicable as structural parameters in the GOH constitutive model of arterial wall if the postulated two fiber families are unified into one with circumferential orientation.

Arterial wall; Carotid artery; Collagen fiber direction; Polarized light microscopy; Histogram

Arterial wall; Carotid artery; Collagen fiber direction; Polarized light microscopy; Histogram

FISCHER, J.; HEIDROVÁ, A.; HERMANOVÁ, M.; BEDNAŘÍK, Z.; JOUKAL, M.; BURŠA, J.

2025

02.03.2024

ELSEVIER

AMSTERDAM

1751-6161

Journal of the Mechanical Behavior of Biomedical Materials

153

5

Nizozemsko

106494-1

106494-9

9

https://www.sciencedirect.com/science/article/pii/S1751616124001267