彩色多普勒超声评价兔颈总动脉结扎后基底动脉的重构

Assessment of rabbits' basilar artery remodeling after common carotid artery ligation by color Doppler ultrasound

目的应用彩色多普勒超声评价兔颈总动脉结扎后基底动脉的重构情况。方法建立兔颈总动脉结扎模型20只,应用彩色多普勒超声分别于结扎术前、术后即刻,以及术后2 d、7 d、30 d观察实验兔基底动脉的走行,测量其内径,记录基底动脉的血流动力学参数,包括:收缩期峰值流速(Vs)、舒张末期流速(Vd)、平均速度(Vm)、阻力指数及搏动指数,计算血流量。结果兔双侧颈总动脉结扎后,基底动脉血流量增多,于术后2 d达到峰值;基底动脉内径增宽,走行扭曲,扭曲程度随时间的延长逐渐加重;术后30 d内径明显增宽,与术前比较差异有统计学意义(P<0.01)。术后2 d的Vs、Vd及Vm到达峰值,随后逐渐减小;阻力指数和搏动指数降低,随后逐渐增加。结论兔双侧颈总动脉结扎后基底动脉在血流量增加的阈值范围内扩张重构,超过阈值则出现明显的弯曲重构,血流量的改变导致其形态学改变,发生重构。

Objective To evaluate the basiliar artery（BA）remodelling after common cartid artery（CCA）ligation in rabbit by color Doppler ultrasound. Methods Twenty healthy rabbits which bilateral CCA were ligatured. The BA of rabbits were examined before operation,and immediately right,2 d,7 d and 30 d after operation respectively by color Doppler ultrasound. The shape and course of BA were observed,the diameters of BA were measured,the hemodynamic parameters such as systole peak velocity（Vs）,diastole velocity（Vd）,mean velocity（Vm）,the pulsatility index（PI） and resistance index（RI） were recorded,the blood flow of BA was computed according to the equation. Results After bilateral carotid artery ligation,the blood flow of BA increased and reached a peak at the 2 nd day after operation,the shape of BA twisted and became severely with time expand,the diameter of BA widened significantly at the 30 th day after operation,there was significant difference compared with that before operation（P 0. 01）. Vs,Vd and Vm reached a peak at the 2 nd day after operation,then began to slow down gradually. Conclusion Increased BA flow results in adaptive BA remodeling following bilateral CCA ligation if it existed in flowincrease threshold,when surpassed,it would result in significant tortuosity. Morphological changes ocured rapidly after flow changed.