Τίτλος:
Regional and directional variations in the layer-specific resistance to tear propagation in ascending thoracic aortic aneurysms
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Aortic dissection often initiates a few centimeters distal to the coronary ostia in the right lateral wall, with an intimal-medial tear that tends to be transversely directed and occupy half of the aortic circumference, sometimes less, but seldom the entire circumference. To elucidate these clinical observations, tear tests were presently used to determine the layer-specific resistance to tear propagation in ascending thoracic aortic aneurysms, assessing variations over the four circumferential quadrants and two directions. Aneurysmal tissue strips of standardized dimensions from sixteen patients were anatomically separated into layers (seven hundred and twelve) and an incision made along one-third of their length. They underwent tear testing via uniaxial loading and then unloading before crack propagation had proceeded along their complete length. The average tear tension and tear energy per reference area generated were many-fold greater in outer- (adventitial) compared to inner- (intimal with small medial portion) and middle-layer (medial) strips, explaining why the tear is restricted to the inner wall. They were greater in inner- compared to middle-layer strips of the anterior and left lateral quadrants, suggesting that the tear will propagate to the less-resistant media even if initiated in the intima. In most longitudinally-cut middle- and inner-layer strips, the cracks deviated toward the circumferential direction and tore out through the side, justifying the circumferential course of the tear. Both fracture parameters were significantly higher in the right than the left lateral quadrant in outer-layer strips and the anterior quadrant in middle-layer strips, potentially affecting the circumferential extent of the tear. © 2022 Elsevier Ltd
Συγγραφείς:
Kefalidi, E.
Angouras, D.C.
Sokolis, D.P.
Περιοδικό:
JOURNAL OF BIOMECHANICS
Εκδότης:
Elsevier Ireland Ltd
Λέξεις-κλειδιά:
Blood vessels; Cracks; Dissection; Unloading, Aortic aneurysms; Aortic quadrant; Ascending aortic aneurysm; Entry tear; Layered wall; Middle layer; Mode III fractures; Mode-III fracture toughness; Specific resistances; Type A dissection, Fracture toughness, adult; aged; aortic valve; Article; ascending aortic aneurysm; clinical article; clinical assessment; comorbidity; controlled study; female; human; human tissue; male; middle aged; observational study; risk factor; tissue preparation; very elderly; adventitia; aorta; biomechanics; dissecting aneurysm; thoracic aorta aneurysm, Adventitia; Aneurysm, Dissecting; Aorta; Aortic Aneurysm, Thoracic; Biomechanical Phenomena; Humans
DOI:
10.1016/j.jbiomech.2022.111133
