镁合金支架植入兔腹主动脉后降解时间及血管内膜增生观察

The degradation time and the intimal hyperplasia of biodegradable magnesium alloy stent implanted in the abdominal aorta of experimental rabbits

目的观察新型可降解镁合金支架——MPM植入兔腹主动脉后降解时间及血管内膜增生。方法 24只新西兰大白兔随机分为4组,每组6只,分别于距左肾动脉水平下1 cm腹主动脉处植入MPM支架各1枚。术后30、60、90、180 d分别复查腹主动脉造影,分离支架段血管进行观察。采用SPSS20.0软件对数据进行分析。结果 24只实验兔在随访期间存活良好。植入支架逐渐降解,180 d时基本降解;血管内膜增生,90 d时达峰值,整个降解过程血管通畅。结论可降解镁合金支架MPM完全降解时间为182 d,可满足血管正性重塑。

Objective To observe the degradation time and the intimal hyperplasia of biodegradable magnesium alloy stent （MPM） implanted in the abdominal aorta of experimental rabbits. Methods A total of 24 New Zealand white rabbits were randomly divided into four groups （30 d, 60 d, 90 d and 180 d） with 6 rabbits in each group. In each rabbit one MPM stent was implanted in the abdominal aorta at the level of one cm below the left renal artery. Reexamination of abdominal aortography with DSA was separately performed at 30, 60, 90 and 180 d after stent implantation to check the stent condition. The rabbits of each group were sacrificed at the corresponding scheduled day, the stenting segment of aorta of each rabbit was removed and the specimen was sent for microscopic examination. The experimental results were analyzed with SPSS20.0 software. Results All the 24 experimental rabbits survived. During the follow-up period the stent showed gradual degradation changes, and basically complete degradation was not observed until to 180 days. Meanwhile, the intimal hyperplasia reached its peak at 90 days after implantation. The abdominal aorta remained unobstructed during the whole process of degradation. Conclusion The time of complete degradation for MPM stent is 182 days, which is long enough to meet the needs of vascular positive remodeling. （J Intervent Radiol, 2017, 26： 443-446）