Τίτλος:
Identification of regional/layer differences in failure properties and thickness as important biomechanical factors responsible for the initiation of aortic dissections
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Thoracic aortic dissections involving the ascending aorta represent one of the most dramatic and lethal emergencies in cardiovascular surgery. It is therefore critical to identify the mechanisms driving them and biomechanical analyses hold great clinical promise, since rupture/dissection occur when aortic wall strength is unable to withstand hemodynamic stresses. Although several studies have been done on the biomechanical properties of thoracic aortic aneurysms, few data are available about thoracic aortic dissections. Detailed mechanical tests with measurement of tissue thickness and failure properties were performed with a tensile-testing device on 445 standardized specimens, corresponding to 19 measurement sites per inner (intima with most of media)/outer layer (leftover media with adventitia); harvested from twelve patients undergoing emergent surgical repair for type A dissection. Our data suggested inherent differences in tissue properties between the origin of dissection and distal locations, i.e. thinner and stiffer inner layers that might render them more vulnerable to tearing despite their increased strength. The strength of tissue circumferentially was greater than that longitudinally, likely determining the direction of tear. The relative strengths of the inner: ∼{65,40}N/cm2 and outer layer: ∼{350,270}N/cm2 in the two principal directions of dissected tissue were differentiated from the intima: ∼{100,75}N/cm2, media: ∼{150,55}N/cm2, and adventitia: ∼{270,190}N/cm2 of non-dissected ascending aortic aneurysms (Sokolis et al., 2012), in favor of weaker inner and stronger outer layers, allowing an explanation as to why the presently-studied tissue suffered dissection, i.e. tear of the inner layers, and not rupture, i.e. full tearing across the entire wall thickness. © 2018 Elsevier Ltd
Συγγραφείς:
Manopoulos, C.
Karathanasis, I.
Kouerinis, I.
Angouras, D.C.
Lazaris, A.
Tsangaris, S.
Sokolis, D.P.
Περιοδικό:
JOURNAL OF BIOMECHANICS
Εκδότης:
Elsevier Ireland Ltd
Λέξεις-κλειδιά:
Biomechanics; Blood vessels; Cardiovascular surgery; Dissection; Failure (mechanical); Tensile testing, Intimal tear; Layered wall; Strength; Thickness; Uniaxial tensions, Tissue, adult; adventitia; aged; aortic dissection; aortic reconstruction; artery wall; Article; biomechanics; clinical article; controlled study; female; hemodynamic stress; human; human tissue; male; middle aged; priority journal; tensile strength; thickness; thoracic aorta; aorta; biomechanics; dissecting aneurysm; intima; mechanical stress; pathophysiology; physiology; thoracic aorta aneurysm, Adult; Adventitia; Aged; Aneurysm, Dissecting; Aorta; Aortic Aneurysm, Thoracic; Biomechanical Phenomena; Female; Humans; Male; Middle Aged; Stress, Mechanical; Tensile Strength; Tunica Intima
DOI:
10.1016/j.jbiomech.2018.08.024
