低孔率球囊扩张支架对犬颈总动脉瘤腔压力的影响

Effect of novel balloon-expandable low porosity stents on blood flow-pressure in common carotid artery aneurysm in canines

目的观察低孔率球囊扩张支架对犬颈总动脉瘤腔压力的影响。方法自行设计中央部分网孔加密而两端与普通类型支架相同（正常孔率区）的低孔率支架，据中央网孔密度高低分为A、B、C三型。取10只犬，于每只犬的双侧颈总动脉建立3个侧壁宽颈动脉瘤模型。将24个成功的动脉瘤按平衡不完全随机设计分为4组：置入A型支架组、B型支架组、C型支架组和空白对照组（仅测压，不置人支架）。采用微导管尾端连接的生物信号分析仪记录瘤腔内和载瘤动脉内的压力变化。结果①18个动脉瘤成功置入支架。置入后即刻造影显示，支架中央低孔率区完全覆盖动脉瘤瘤颈，支架贴壁良好，载瘤动脉血流通畅。所有动脉瘤内血流减慢，其中12个（66．7％）瘤体减小。置入支架组均无血栓形成及支架移位。②3个支架组支架置入前、置入后动脉瘤内的压力差异均无统计学意义，与空白对照组比较差异亦无统计学意义。在支架置人过程中，3个支架组动脉瘤内压力均比对照组及自身置入前、置入后升高（P〈0．05，P〈0．01）；而3个支架组间差异无统计学意义（P〉0．05）。③支架置入后载瘤动脉内压力，3个支架组间比较差异无统计学意义，与空白对照组比较，差异亦无统计学意义。支架置入后，各组自身比较，动脉瘤内压力与载瘤动脉内压力差异亦无统计学意义。结论低孔率支架置入后，可使动脉瘤内血流速度减慢，血液流空时间延长。不影响动脉瘤和载瘤动脉内压力的变化，仅在支架释放的过程中可引起动脉瘤腔内压力的短暂性升高。

Objective To observe the effect of novel balloon-expandable low porosity stents on blood flow-pressure in common carotid artery （ CCA ） aneurysm in canines. Methods Three types of novel stents with low porosity in the central part and normal porosity at the two ends were designed and made, and they were divided into type A, B, and C according to their porosity in the central part. Ten dogs were selected, and three lateral wall wide-necked aneurysm models were established at the bilateral carotid artery of each dog. According to the balance and incomplete random design, 24 successful aneurysm models were divided into 4 groups： type A, B, C stent and control （only measuring pressure, and no stenting） groups. The changes of blood flow pressure in aneurismal cavities and parent arteries were recorded with a biological signal analyzer that was connected by the end of microcatheters. Results （1）Stents were implanted successfully in 18 aneurysms. Immediately after the procedure, angiography showed that the aneurysmal necks were completely covered by the central low porosity area of the stents, and there was no stent malapposition and no obstruction of the parent arteries. The blood flow velocity in all the aneurysms were decreased, and 12 aneurysms （66.7%） decreased in size. （2）There were no statistically significant differences among the 4 groups in the blood flow pressure in aneurysms before and after the stenting. During the stent implantation, the pressure in aneurysms in all the 3 groups were higher than that in the control group and themselves before and after the stenting （P 〈 0.05, P 〈 0.01 ） ; however, there were no significant differences among the 3 stent groups （ P 〉 0.05 ）. （3）There were no significant differences among the 4 groups in the blood flow pressure in aneurysms after the stent implantation. After the stent implantation, there were no significant differences between the pressures in aneurysms and parent arteries compared to each group. Conclusion After implantation of the novel low porosity stent, it may decrease the blood flow velocity in aneurysms, and prolong the time of blood flow void. It does not influence the changes of blood flow pressure in aneurysms and parent arteries ; however, it only causes a transient rise of blood flow pressure in aneu .rysms during the stent implantation.