The Effect of Mechanical Overloading on Surface Roughness of the Coronary Arteries

Abstract

Background. Surface roughness can be used to identify disease within biological tissues. Quantifying surface roughness in the coronary arteries aids in developing treatments for coronary heart disease. This study investigates the effect of extreme physiological loading on surface roughness, for example, due to a rupture of an artery. Methods. The porcine left anterior descending (LAD) coronary arteries were dissected ex vivo. Mechanical overloading was applied to the arteries in the longitudinal direction to simulate extreme physiological loading. Surface roughness was calculated from three-dimensional reconstructed images. Surface roughness was measured before and after damage and after chemical processing to dehydrate tissue specimens. Results. Control specimens confirmed that dehydration alone results in an increase of surface roughness in the circumferential direction only. No variation was noted between the hydrated healthy and damaged specimens, in both the longitudinal (0.91±0.26 and 1.05±0.25 μm) and circumferential (1.46±0.38 and 1.47±0.39 μm) directions. After dehydration, an increase in surface roughness was noted for damaged specimens in both the longitudinal (1.28±0.33 μm) and circumferential (1.95±0.56 μm) directions. Conclusions. Mechanical overloading applied in the longitudinal direction did not significantly affect surface roughness. However, when combined with chemical processing, a significant increase in surface roughness was noted in both the circumferential and longitudinal directions. Mechanical overloading causes damage to the internal constituents of the arteries, which is significantly noticeable after dehydration of tissue.

Mathematical Analysis of Heat Transfer in Peristaltic Transport through a Rough Nonuniform Inclined Channel

“…and magnitude of various parameters is taken as a � 0.01 cm, L � λ � 10 cm, K � 0.5(a/L) � 0.0005 [14,15], and ϕ 1 � (b 1 /a); the magnitude of b 1 is from [28]. Figure 2 that, during one period of the wave, an increase in the angle of inclination enhances the pressure rise.…”

“…Evaluation of surface roughness of coronary arteries, in which blood flow takes place through the peristaltic mechanism, helps in developing a remedy for coronary heart disease. Burton and Espino [28] investigated the consequences of intense physiological loading on surface roughness; from the observations, it was revealed that initially, mechanical overloading has no significant effect on roughness; however, when a chemical processing was applied on the surface, an increase in surface roughness was noticed in the longitudinal and circumferential directions.…”

The status and challenges of replicating the mechanical properties of connective tissues using additive manufacturing

“…Tensile strength: 0.4 MPa (Holzapfel et al, 2005) Intima 0.39 MPa (Holzapfel et al, 2005) Media 0.45 MPa (Holzapfel et al, 2005) Adventitia 1.4 MPa (Holzapfel et al, 2005) AORTA (thoracic): 0.8 -5.1 MPa Ascending aorta 1.0-2.2 MPa (Iliopoulos et al, 2009;Jarrahi et al, 2016;Vorp et al, 2003) Descending aorta 0.8 -5.1 MPa (Adham et al, 1996;Groenink et al, 1999;Melvin, 1982, 1983;Stemper et al, 2007) FEMORAL: ≥0.3 MPa (Schulze-Bauer et al, 2002;Syedain et al, 2011) Failure stress does not necessarily mean full 'fracture' and more subtle signs of damage may be noticeable at below failure stress (Burton and Espino, 2019) Longitudinal and transverse samples, rate of loading (Mohan and Melvin, 1982), animal samples or human samples, age, and testing using uniaxial or biaxial set-ups (O'Leary et al, 2014) will lead to different elastic moduli. Some of these points have been highlighted for coronary arteries, along with the difference between low and high stress characterisation (but not for aorta and femoral arteries, to avoid repetition)…”

Effect of Surface Roughness during Peristaltic Movement in a Nonuniform Channel

“…Following parameter values have been used: a � 0.01 cm, L � λ � 10 cm, K � 0.5(a/L) � 0.0005 [5,25], and ϕ 1 � (b 1 /a), where the value of b 1 is taken from [13].…”

“…Knowledge of the effect of surface roughness during transportation of physiological fluids is very useful in understanding various problems related to blood flow in coronary arteries (Park et al [12] and Burton and Espino [13]). Effect on flow due to surface roughness has captured the interest of researchers in chemical engineering to understand the consequence of roughness of walls formed as a result of chemical erosion during transportation of chemicals.…”