TY - JOUR
T1 - Evaluation of Rupture Properties of Thoracic Aortic Aneurysms in a Pressure-Imposed Test for Rupture Risk Estimation
AU - Sugita, Shukei
AU - Matsumoto, Takeo
AU - Ohashi, Toshiro
AU - Kumagai, Kiichiro
AU - Akimoto, Hiroji
AU - Tabayashi, Koichi
AU - Sato, Masaaki
N1 - Funding Information:
The authors thank patients who allowed us to use their aneurysm specimens. The present study was supported in part by Grants-in-Aid for Young Scientists (B) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan (No. 22700467) and the Science and Technology Promotion Adjustment Cost Program from the Japan Science and Technology Agency.
PY - 2012/3
Y1 - 2012/3
N2 - Rupture properties of thoracic aortic aneurysms (TAAs) were measured in vitro in a pressure-imposed test to predict the ultimate stress of TAAs from their mechanical behavior in a physiological pressure range. Each quadrilateral (ca. 20 × 20 mm2) specimen of TAAs or porcine thoracic aortas (PTAs) was pressurized from the inner wall until rupture or up to 4500 mmHg, while its deformation was being monitored. In-plane stress σ and strain ε of the specimen were calculated using Laplace's law and deformations of the markers drawn on the specimen surface, respectively. Ultimate stress σmax and tangent elastic modulus H were determined from the σ-ε curve as its maximum stress and slope, respectively. The tangent elastic modulus H of PTA specimens tended to increase with the increase in σ, while that of TAA specimens tended to reach a plateau in a low-σ region. This tendency was confirmed by fitting a function H = Cσ(1 - exp(-σ/τσ)) to the H-σ relation of specimens: The yielding parameter τσ was significantly lower in TAAs than PTAs. Furthermore, the logarithm of the parameter τσ correlated significantly with σmax, for all specimens. These results may indicate that τσ is one of the candidate indices for rupture risk estimation.
AB - Rupture properties of thoracic aortic aneurysms (TAAs) were measured in vitro in a pressure-imposed test to predict the ultimate stress of TAAs from their mechanical behavior in a physiological pressure range. Each quadrilateral (ca. 20 × 20 mm2) specimen of TAAs or porcine thoracic aortas (PTAs) was pressurized from the inner wall until rupture or up to 4500 mmHg, while its deformation was being monitored. In-plane stress σ and strain ε of the specimen were calculated using Laplace's law and deformations of the markers drawn on the specimen surface, respectively. Ultimate stress σmax and tangent elastic modulus H were determined from the σ-ε curve as its maximum stress and slope, respectively. The tangent elastic modulus H of PTA specimens tended to increase with the increase in σ, while that of TAA specimens tended to reach a plateau in a low-σ region. This tendency was confirmed by fitting a function H = Cσ(1 - exp(-σ/τσ)) to the H-σ relation of specimens: The yielding parameter τσ was significantly lower in TAAs than PTAs. Furthermore, the logarithm of the parameter τσ correlated significantly with σmax, for all specimens. These results may indicate that τσ is one of the candidate indices for rupture risk estimation.
KW - Mechanical property
KW - Pressure-imposed test
KW - Rupture estimation
KW - Tangent elastic modulus
KW - Thoracic aortic aneurysm
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U2 - 10.1007/s13239-011-0067-1
DO - 10.1007/s13239-011-0067-1
M3 - Article
AN - SCOPUS:84857934763
VL - 3
SP - 41
EP - 51
JO - Cardiovascular Engineering and Technology
JF - Cardiovascular Engineering and Technology
SN - 1869-408X
IS - 1
ER -