血流动力学改变诱导的兔基底动脉顶端动脉瘤模型

目的 尝试采用结扎新西兰大白兔双侧颈总动脉诱导基底动脉顶端动脉瘤生成。方法 新西兰大白兔26只，分别游离双侧颈总动脉，不行结扎（假手术组，n=6）或结扎（实验组，n=20）双侧颈总动脉。分别于结扎前（0 d）、术后1 d、1周、4周经颅多普勒超声测量基底动脉血流速度；术后4周行脑血管造影了解基底动脉变化；术后1周、4周取基底动脉观察动脉形态变化并对分叉部行组织学检查。结果 假手术组动物全部成活，实验组术后存活率为80%（16/20）。实验组术后1 d，基底动脉血流速度直线升高，高于术前226%；术后1周仍在持续升高；术后4周血流速度处于稳定状态。实验组术后1周，基底动脉增粗，明显迂曲；而假手术组无明显变化。实验组基底动脉分叉部中膜厚度变薄；内弹力层部分消失、断裂或变薄。结论 双侧颈总动脉结扎所致血流动力学改变可诱导兔基底动脉顶端出现新生动脉瘤样改变。

Basilar terminus aneurysm model of rabbit induced by hemodynamic changes

Objective To use bilateral common carotid artery ligation for creating an aneurysm model of the basilar terminus in New Zealand white rabbits. Methods Twenty-six adult New Zealand white rabbits were subjected to sham operation or bilateral common carotid artery ligation to increase basilar artery flow. Basilar artery flow velocity was monitored by transcranial Doppler before the operation, and 1 d, 1 week, and 4 weeks after surgery. Cerebral angiography was performed 4 weeks after surgery to observe the changes of basilar arteries. The basilar arteries were harvested to observe the morphological changes of the arteries and the histological characteristics of the bifurcation tissues 1 week and 4 weeks after the surgery. Results All animals survived in the sham group, and 80% (16/20) of the animals survived in the experimental group. The basilar artery flow velocity increased sharply one day after operation (increased by 226%) in the experimental group, and it kept increasing 1 week after the operation until reaching a stable state 4 weeks after operation. The basal arteries were dilated obviously and displayed tortuous formation after one week in the experimental group, but there was no such change in the sham group. All rabbits in the experimental group presented with thinned media and absent, disrupted or thinned internal elastic lamina near the basilar terminus. Conclusion Blood flow increase at the basilar bifurcation caused by ligation of the bilateral common carotid arteries can lead to aneurysmal change at the basilar terminus of New Zealand white rabbits.