Echotracking联合microCT评价可降解支架植入后动脉弹性改变

Study of Artery Elasticity Changes of Rabbits' Abdominal Aorta after Biodegradable JDBM Stent Implanted by Echotracking Combined with Micro CT

目的:通过建立可降解支架植入兔腹主动脉模型,探讨echotracking联合mircoCT在支架降解过程中动态观察动脉弹性改变的价值。方法:24只新西兰大白兔于DSA下在其腹主动脉随机植入一枚可降解镁合金支架(JDBM组,n=12)或镍钛合金支架(BMS组,n=12),分别于术前和植入术后即时、14天、30天、60天行echotracking获得支架处血管硬化参数β,并在术后第14天、30天、60天取材行micro CT评价支架降解情况。结果:(1)观察期间支架无移位或断裂,支架内血流通畅。(2)Micro CT提示BMS支架无明显变化,JDBM支架术后30天起已开始降解,观察期间支架基本保持原始结构,合金丝连续性完整。(3)术前及术后即时、第14天两组间β值无明显统计学差异(P>0.05),随植入时间的增加,JDBM组β值逐渐减小,BMS组β值逐渐增大;术后30天时JDBM组明显小于BMS组(P=0.036);术后60天时BMS组β值因支架处管壁无明显搏动无法获得。结论:Echotracking技术联合mirco CT可用于评价可降解镁合金支架植入后降解过程中血管弹性的改变情况。

Purpose： To determine whether echotracking combined with microCT could be used to assess the artery elasticity during the degradation processes. Methods： Either bare biodegradable magnesium alloy JDBM stent （JDBM group, n=12） or bare nitinol stent （BMS group, n=12） were implanted in New Zealand white rabbits＇ abdominal arteries. Echotracking was performed to obtain the stiffness parameter 13 before operation, immediate post-operation, 14, 30 and 60 days post-operation. The degradation of the stents was analyzed by mirco CT at the 14, 30 and 60 days after operation. Results：① There was no migration or fracture of all the stents,and the blood flow in stent was normal. ②MircoCT showed that the nitinol stents were with no changes. The JDBM stents began to degrade since 30 days afteroperation. But their structures maintained well and the struts were in continuity. ③There was no statistical significant difference of β between each groups before operation, immediate post-operation, or 14 days post-operation （P 〉 0.05）. As the implanted time went by, β of JDBM group was significantly lower than that of BMS group（P =0.036） at 30 days post-operation. However, D of BMS group was immeasurable at the 60 days post-operation because of the undetectable vessel diameter changes. Conclusion： Echotracking combined with microCT could be used to assess the artery elasticity during the degradation processes of JDBM.