Biomedical Engineering Reference
In-Depth Information
Fig. 11.6
(
A
) Representative SEM images of fracture surfaces of the non-aneurysmal and ATAA
with BAV and TAV in LONG and CIRC direction; (
B
) high magnification image of a CIRC TAV
ATAA for the INT-DEL half showing bundles of broken elastin fibers (
F
) existing between elas-
tic sheets (
E
). The fibers act like a 'bridge' between halves in a fracture modality called 'fiber
bridging' in delamination testing. Taken from Pasta et al. (
2011
)
of AoD have been described (Tiessen and Roach,
1993
), but the onset of dissec-
tion was typically forced in these studies by injecting liquid with a syringe into the
media to separate the aortic lamellae. Additionally, the stresses that lead to AoD are
likely multi-factorial and could be composed of stresses due to blood pressure, shear
stresses due to the blood flow field, torsion due to heart motion or propagation of the
pressure pulse, etc. However, the purpose of this investigation was not to simulate
these forces, but rather to measure the resistance of the tissue to stresses induced by
delamination (i.e., bonding forces between the mural layers of the aortic wall, or the
delamination strength). Future work could be to investigate correlation not observed
in this investigation between tissue strength and aortic diseases as the aortic stenosis
and regurgitation.
