椎动脉闭塞血管重建术改善近、远期后脑区域血供的实验研究

Improvement of blood supplies of hindbrain in short and long term by reconstruction of vertebral artery occluded blood vessel

目的:应用客观,定量评估方法研究椎动脉闭塞后血管重建术后改善小脑血供的近、远期疗效。方法:用23只成年杂种犬经颈部阻断两侧椎动脉和一侧颈总动脉,制成椎基动脉供血不足疾病模型,随后实施同侧椎动脉-颈总动脉端侧吻合术重建椎动脉。以氢清除法测定术后近、远期局部小脑血流量;超声多普勒测定椎动脉血流速度;数字减影血管造影(D)及磁共振SA(M)观察吻合口及小脑结构。RI结果:术后近期局部小脑组织血流量达212.5±77.9)/((μLg·min),较阻断术后增加25%,达阻断术前的81%;椎动脉内血流的最高、最低流速分别为(5.49±2.36),(3.47±0.77)cm/s,均有提高,后者提高显著。3个月后,局部小脑血流量为(253.3±72.2)μL(·/gmin),进一步提高15.86%;数字减影血管造影及磁共振血管成像显示吻合口通畅,颈部血管侧支循环建立;后脑磁共振扫描未见梗死性病变;实验犬均正常存活。结论:椎动脉重建术对恢复椎基底动脉血供,改善后脑供血,近期疗效肯定,远期疗效亦随时间的延长成正性关系。

AIM:To investigate the effect of cerebellar blood supply in short and long term after reconstruction of vertebral artery(VA) occluded blood vessel with objective and quantitative assessment. METHODS:A model of vertebrobasilar artery insufficiency(VBI) was established by interrupting bilateral VA and unilateral common carotid artery(CA) on 23 adult hybrid dogs,then the blood supply of VA was recovered by an end side anastomosis between VA and CA.The local tissue blood(LTB) of cerebellum was monitored with hydrogen clearance method,the blood flow speed of VA was detected by Ultrasonic Doppler and the stoma and constitution of cerebellum were observed by digital subtraction anglography(DSA) and MRI. RESULTS:LTB of cerebellum after VA reconstruction was(212.5±77.9) μL/g per minute,increased by 25% compared with that after interruption, and reached to 81% of the data before interruption;The maximal and minimal blood flow speeds were(5.49±2.36),(3.47±0.77)cm/s respectively,and both of them increased,especially the latter one.LTB of cerebellum was(253.3±72.2) μL/g per minute 3 months later,and it increased by 15.86%.DSA and MRI showed that the stoma was smooth and collateral circulation of cervical blood vessel was formed,no infarct focus was detected by MRI on hind brain,and all experimental dogs lived normally. CONCLUSION:The VA reconstruction can achieve a better short term effect by recovering the blood supply of vertebrobasilar artery and improving the blood flow of hindbrain effectively.The long term effect also has a positive relation with the increasing of time.