A theoretical model for fibroblast-control led growth of saccular cerebral aneurysms
A theoretical model for fibroblast-control led growth of saccular cerebral aneurysms
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DOI：
10.1016/j.jtbi.2008.10.021
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发表时间：
2009-03-07
影响因子：
2
通讯作者：
Holzapfel, Gerhard A.
中科院分区：
文献类型：
--
作者：
Kroon, Martin;Holzapfel, Gerhard A.
通过扩展Kroon和Holzapfel [2007 a.]的最新构成框架，提出了一种新的囊状脑动脉瘤生长的理论模型。利用胶原纤维重塑建立囊状脑动脉瘤生长模型。J.西奥。247，775-787]。胶原蛋白的不断更新被认为是细胞生长的驱动机制。胶原蛋白的产生率取决于成纤维细胞的周期性变形的大小，这是由心动周期期间的脉动血压引起的。在整个生长过程中，成纤维细胞在囊性组织中的体积密度是恒定的。通过考虑动脉瘤组织的轴对称膜片的膨胀来评估生长模型，其材料特征代表脑动脉瘤。计算动脉瘤的舒张和收缩状态以及其无负荷状态。事实证明，决定动脉瘤生长速度和稳定性的胶原蛋白预拉伸值至关重要。该模型能够预测临床观察到的具有典型浆果状形状的动脉瘤，并且预测的壁应力与实验获得的这种类型组织的极限应力相关性良好。该模型预测，动脉瘤在达到约1.2-3.6 mm的尺寸时应该失效，这比临床观察到的尺寸要小。然而，经过一些改进，该模型可用于预测诊断出的动脉瘤的未来生长。(C)2008爱思唯尔有限公司版权所有。
A new theoretical model for the growth of saccular cerebral aneurysms is proposed by extending the recent constitutive framework of Kroon and Holzapfel [2007a. A model for saccular cerebral aneurysm growth by collagen fibre remodelling. J. Theor. Biol. 247, 775-787]. The continuous turnover of collagen is taken to be the driving mechanism in aneurysmal growth. The collagen production rate depends on the magnitude of the cyclic deformation of fibroblasts, caused by the pulsating blood pressure during the cardiac cycle. The volume density of fibroblasts in the aneurysmal tissue is taken to be constant throughout the growth process. The growth model is assessed by considering the inflation of an axisymmetric membranous piece of aneurysmal tissue, with material characteristics representative of a cerebral aneurysm. The diastolic and systolic states of the aneurysm are computed, together with its load-free state. It turns out that the value of collagen pre-stretch, that determines growth speed and stability of the aneurysm, is of pivotal importance. The model is able to predict aneurysms with typical berry-like shapes observed clinically, and the predicted wall stresses correlate well with the experimentally obtained ultimate stresses of this type of tissue. The model predicts that aneurysms should fail when reaching a size of about 1.2-3.6 mm, which is smaller than what has been clinically observed. With some refinements, the model may, however, be used to predict future growth of diagnosed aneurysms. (C) 2008 Elsevier Ltd. All rights reserved.