Ex vivo regional mechanical characterization of porcine pulmonary arteries

Yükleniyor...
Küçük Resim

Tarih

2021

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Springer

Erişim Hakkı

info:eu-repo/semantics/openAccess

Özet

Background: Regional mechanical characterization of pulmonary arteries can be useful in the development of computational models of pulmonary arterial mechanics. Objective: We performed a biomechanical and microstructural characterization study of porcine pulmonary arteries, inclusive of the main, left, and right pulmonary arteries (MPA, LPA, and RPA, respectively). Methods: The specimens were initially stored at ?20 °C and allowed to thaw for 12–24 h prior to testing. Each artery was further subdivided into proximal, middle, and distal regions, leading to ten location-based experimental groups. Planar equibiaxial tensile testing was performed to evaluate the mechanical behavior of the specimens, from which we calculated the stress at the maximum strain (S55), tensile modulus (TM), anisotropy index (AI), and strain energy in terms of area under the stress-strain curve (AUC). Histological quantification was performed to evaluate the area fraction of elastin and collagen content, intima-media thickness (IMT), and adventitial thickness (AT). The constitutive material behavior of each group was represented by a five-constant Holzapfel-Gasser-Ogden model. Results: The specimens exhibited non-linear stress-strain characteristics across all groups. The MPA exhibited the highest mean wall stress and TM in the longitudinal and circumferential directions, while the bifurcation region yielded the highest values of AI and AUC. All regions revealed a higher stiffness in the longitudinal direction compared to the circumferential direction, suggesting a degree of anisotropy that is believed to be within the margin of experimental uncertainty. Collagen content was found to be the highest in the MPA and decreased significantly at the bifurcation, LPA and RPA. Elastin content did not yield such significant differences amongst the ten groups. The MPA had the highest IMT, which decreased concomitantly to the distal LPA and RPA. No significant differences were found in the AT amongst the ten groups. Conclusion: The mechanical properties of porcine pulmonary arteries exhibit strong regional dissimilarities, which can be used to inform future studies of high fidelity finite element models.

Açıklama

Anahtar Kelimeler

Constitutive Modeling, Histology, Planar Biaxial Tension, Pulmonary Arterial Mechanics, Pulmonary Hypertension

Kaynak

Experimental Mechanics

WoS Q Değeri

Q2

Scopus Q Değeri

Q2

Cilt

Sayı

Künye

Pillalamarri, N. R., Patnaik, S. S., Piskin, S., Gueldner, P., & Finol, E. A. Ex Vivo Regional Mechanical Characterization of Porcine Pulmonary Arteries. Experimental Mechanics, 1-19.