In vivo assessment of rapid cerebrovascular morphological adaptation following acute blood flow increase.
In vivo assessment of rapid cerebrovascular morphological adaptation following acute blood flow increase.
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DOI：
10.3171/jns.2008.109.12.1141
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发表时间：
2008-12
影响因子：
4.1
通讯作者：
Mocco J
中科院分区：
文献类型：
--
作者：
Hoi Y;Gao L;Tremmel M;Paluch RA;Siddiqui AH;Meng H;Mocco J
脑血管重塑的病理极端可能导致基底动脉（BA）过度扩张和梭状动脉瘤的发展。调控脑血管重构的因素尚不清楚。为了更好地了解血流动力学对脑血管重塑的影响，我们在动物模型中检测了颈总动脉结扎后的BA重塑。采用假手术（3只）、单侧CCA结扎（3只）、双侧CCA结扎（5只）。在第0、1、4、7、14、28、56、84天，采用经颅多普勒超声和旋转血管造影计算BA流量、直径、壁剪切应力（WSS）和扭曲指数。第84天对基底动脉组织进行染色分析。统计分析采用正交对比分析、重复测量方差分析或重复测量混合回归分析。统计学显著性定义为概率值< 0.05。两组结扎后基底动脉流量和直径均显著增加，但只有双侧CCA结扎组组间差异有统计学意义。只有双侧CCA结扎组动物的壁剪切应力显著增加，并在第28天恢复到基线水平，第7天出现52%的WSS纠正。只有双侧CCA结扎组在结扎后7天内出现明显的BA扭曲。与假手术组和单侧CCA结扎组不同，双侧CCA结扎组动物的组织学染色结果显示大量的内部弹性板碎裂。BA流量增加导致适应性BA重塑，直到WSS恢复到生理基线水平。形态变化在血流改变后迅速发生，不需要慢性损伤就能影响实质性和显著的结构转变。此外，似乎存在一个流量增加阈值，当超过该阈值时，会导致显著的弯曲。
Pathological extremes in cerebrovascular remodeling may contribute to basilar artery (BA) dolichoectasia and fusiform aneurysm development. Factors regulating cerebrovascular remodeling are poorly understood. To better understand hemodynamic influences on cerebrovascular remodeling, we examined BA remodeling following common carotid artery (CCA) ligation in an animal model. Rabbits were subjected to sham surgery (3 animals), unilateral CCA ligation (3 animals), or bilateral CCA ligation (5 animals). Transcranial Doppler ultrasonography and rotational angiography were used to compute BA flow, diameter, wall shear stress (WSS), and a tortuosity index on Days 0, 1, 4, 7, 14, 28, 56, and 84. Basilar artery tissues were stained and analyzed at Day 84. Statistical analysis was performed using orthogonal contrast analysis, repeated measures analysis of variance, or mixed regression analysis of repeated measures. Statistical significance was defined as a probability value < 0.05. Basilar artery flow and diameter increased significantly after the procedure in both ligation groups, but only the bilateral CCA ligation group demonstrated significant differences between groups. Wall shear stress significantly increased only in animals in the bilateral CCA ligation group and returned to baseline by Day 28, with 52% of WSS correction occurring by Day 7. Only the bilateral CCA ligation group developed significant BA tortuosity, occurring within 7 days postligation. Unlike the animals in the sham and unilateral CCA ligation groups, the animals in the bilateral CCA ligation group had histological staining results showing a substantial internal elastic lamina fragmentation. Increased BA flow results in adaptive BA remodeling until WSS returns to physiological baseline levels. Morphological changes occur rapidly following flow alteration and do not require chronic insult to affect substantial and significant structural transformation. Additionally, it appears that there exists a flow-increase threshold that, when surpassed, results in significant tortuosity.