Influence of material property variability on the mechanical behaviour of carotid atherosclerotic plaques: a 3D fluid-structure interaction analysis.
Mechanical analysis has been shown to be complementary to luminal stenosis in assessing atherosclerotic plaque vulnerability. However, patient-specific material properties are not available and the effect of material properties variability has not been fully quantified. Media and fibrous cap (FC) strips from carotid endarterectomy samples were classified into hard, intermediate and soft according to their incremental Young's modulus. Lipid and intraplaque haemorrhage/thrombus strips were classified as hard and soft. Idealised geometry-based 3D fluid-structure interaction analyses were performed to assess the impact of material property variability in predicting maximum principal stress (Stress-P1 ) and stretch (Stretch-P1 ). When FC was thick (1000 or 600 µm), Stress-P1 at the shoulder was insensitive to changes in material stiffness, whereas Stress-P1 at mid FC changed significantly. When FC was thin (200 or 65 µm), high stress concentrations shifted from the shoulder region to mid FC, and Stress-P1 became increasingly sensitive to changes in material properties, in particular at mid FC. Regardless of FC thickness, Stretch-P1 at these locations was sensitive to changes in material properties. Variability in tissue material properties influences both the location and overall stress/stretch value. This variability needs to be accounted for when interpreting the results of mechanical modelling.
Department of Radiology, University of Cambridge, Cambridge, CB2 0QQ, UK.
Jianmin
J
Yuan
Department of Radiology, University of Cambridge, Cambridge, CB2 0QQ, UK.|Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK.
Zhongzhao
Z
Teng
Department of Vascular Surgery, Changhai Hospital, Changhai Road, Shanghai, 200433, China.
Jiaxuan
J
Feng
Department of Radiology, University of Cambridge, Cambridge, CB2 0QQ, UK.|Department of Vascular Surgery, Changhai Hospital, Changhai Road, Shanghai, 200433, China.
Yongxue
Y
Zhang
Division of Cardiovascular Medicine, University of Cambridge, Cambridge, CB2 1TN, UK.
Adam J
AJ
Brown
Department of Radiology, University of Cambridge, Cambridge, CB2 0QQ, UK.
Jonathan H
JH
Gillard
Department of Vascular Surgery, Changhai Hospital, Changhai Road, Shanghai, 200433, China.
Zaiping
Z
Jing
Department of Vascular Surgery, Changhai Hospital, Changhai Road, Shanghai, 200433, China.
Qingsheng
Q
Lu
D050197:Atherosclerosis / Q000378:metabolism / Q000473:pathology; D002339:Carotid Arteries / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional; D008955:Models, Cardiovascular; D058226:Plaque, Atherosclerotic / Q000737:chemistry*; D013314:Stress, Mechanical
atherosclerosis; material property; mechanics; sensitivity; stress; stroke