Repeated Loading Behavior of Pediatric Porcine Common Carotid Arteries

Abstract

Rapid flexion and extension of the neck may occur during scenarios associated with traumatic brain injury (TBI), and understanding the mechanical response of the common carotid artery (CCA) to longitudinal stretch may enhance understanding of contributing factors that may influence CCA vasospasm and exacerbate ischemic injury associated with TBI. Immature (4-week-old) porcine CCAs were tested under subcatastrophic (1.5 peak stretch ratio) cyclic loading at 3 Hz for 30 s. Under subcatastrophic cyclic longitudinal extension, the immature porcine CCA displays softening behavior. This softening can be represented by decreasing peak stress and increasing corner stretch values with an increasing number of loading cycles. This investigation is an important first step in the exploration of fatiguelike behavior in arterial tissue that may be subjected to repeated longitudinal loads.

Failure and Fatigue Properties of Immature Human and Porcine Parasagittal Bridging Veins

“…and child abuse (shaking or repeated blows to the head) resulting in numerous BV elongations. With exposure to prolonged cyclic elongation to the same subcatastrophic peak displacement, we observe softening of the BVs characterized by decreasing peak stresses (Figures 1–3), and lengthening of the low-stress “toe” region, such that stiffer behavior occurs at increasingly higher stretch ratios (Figure 4), also observed in immature porcine common carotid arteries 43 , and in agreement with findings from a longitudinal over-stretch study of ovine middle cerebral arteries 2 . This softening is also exemplified by significantly smaller low stretch regime moduli and larger corner stretches in post-cyclic failure testing compared to low rate failure testing, performed at similar though significantly lower stretch rates than post-cyclic tests.…”

“…Furthermore, there have been few other studies to measure axial behavior of any blood vessel under cyclic loading 19, 20, 25, 32, 43 , with most focused on the first five cycles 19, 20, 25, 32 . Our study was designed to mimic scenarios of repeated single loads or cyclic head rotations in both sports (e.g.…”

“…A custom device coupling a rotary motor to a gear chain drive, described previously, 43 was used to perform elongation tests. BVs were gripped by flat plate-type grips similar to prior investigations, 12, 30, 31, 38, 40, 41 as cannulation and fluid perfusion risked pre-test damage to the delicate BVs.…”

Development of biomimetic thermoplastic polyurethane/fibroin small‐diameter vascular grafts via a novel electrospinning approach

“…49 Similar to natural soft tissues, the first cycle of the grafts was for stress softening and directional stretching and loosening pulled the fibers apart and reoriented them, making the stress-strain behavior different from the rest of cycles. 54 According to the experimental results, the circumferential cyclic behaviors of all of the TPU/fibroin grafts were in good agreement with that of natural human coronary arteries. The wavy structure created by the assembled rotating collector effectively increased the toe region and showed no structural damage during repeated loadings, providing the grafts with the capacity for long-term usage.…”

“…Figure shows the recorded stress–strain curves of the 1st, 100th, 200th, and 300th cycles for each group, where the scatter data points represent the experimental stress–strain range of human coronary arteries from other research . Similar to natural soft tissues, the first cycle of the grafts was for stress softening and directional stretching and loosening pulled the fibers apart and reoriented them, making the stress–strain behavior different from the rest of cycles . According to the experimental results, the circumferential cyclic behaviors of all of the TPU/fibroin grafts were in good agreement with that of natural human coronary arteries.…”