Comparative mechanics of diverse mammalian carotid arteries

Abstract

The prevalence of diverse animal models as surrogates for human vascular pathologies necessitate a comprehensive understanding of the differences that exist between species. Comparative passive mechanics are presented here for the common carotid arteries taken from bovine, porcine, ovine, leporine, murine-rat, and murine-mouse specimens. Data is generated using a scalable biaxial mechanical testing device following consistent circumferential (pressure-diameter) and axial (force-length) testing protocols. The structural mechanical response of carotids under equivalent loading, quantified by the deformed inner radius, deformed wall thickness, lumen area compliance and axial force, varies significantly among species but generally follows allometric scaling. Conversely, descriptors of the local mechanical response within the deformed arterial wall, including mean circumferential stress, mid-wall circumferential stretch, and mean axial stress, are relatively consistent across species. Unlike the larger animals studied, the diameter distensibility curves of murine specimens are non-monotonic and have a significantly higher value at 100 mmHg. Taken together, our results provide baseline structural and mechanical information for carotid arteries across a broad range of common animal models.

Absence of LTBP-3 attenuates the aneurysmal phenotype but not spinal effects on the aorta in Marfan syndrome

“…Davies et al 2006), we are not aware of a previously validated scaling for mice. Although normalization by body mass may seem to be natural(Chen et al 2017;Guo et al 2018), aortic growth scales allometrically, not isometrically, with body mass(West et al 1997), hence it is prudent to use allometric scaling (d = α ⋅ M β , with α > 0 and β < 1) to compare aortic diameters across different genotypes(Hayashi and Sugimoto 2007;Matsumoto and Hayashi 1994) or species(Goergen et al 2007;Greve et al 2006;Prim et al 2018). Given that the parameter values for allometric scaling of the inner diameter of the ATA may vary with sex, age, and range of body mass (de Simone et al 1997), prior data from n = 21 age-and sexmatched wild-type mice with similar genetic backgrounds and body mass to those of the mice studied here (~17 to 40 g) were used to identify the two model parameters.…”

Resorbable vascular grafts show rapid cellularization and degradation in the ovine carotid

“…The achieved safety factor was 13. Additionally, given ~1 N estimates of the axial loads in the sheep carotid (Prim et al, 2018), we adjusted the fiber alignment of the PCL sheath such that the axial strength was approximately twice the circumferential. An earlier implant attempt using a thinner PCL sheath and a safety factor of 5 had resulted in 3/4 graft ruptures within approximately 10 days, with 3/4 ruptures known to have occurred within minutes of animals distending their necks (data not shown).…”

Small‐diameter artery decellularization: Effects of anionic detergent concentration and treatment duration on porcine internal thoracic arteries

“…where l and L are the suture-to-suture deformed and undeformed lengths, respectively. The average circumferential σ θ and axial σ z stresses were (see also Prim et al 2018):…”

“…,42 Conservation of key biomechanical properties such as mean circumferential stress, mid-wall circumferential stretch, and mean axial stress across several species further supports the use of xenogeneic tissue sources as future grafting scaffolds 42. …”