新型血管内可吸收镁合金支架的实验研究

目的评估自行设计制作的新型血管内可吸收镁合金支架的生物相容性、有效性和安全性。方法杂种犬35只,每只犬均于冠状动脉和股动脉置入可吸收镁合金支架1枚,分别于术后1、3、5 d和1、2、3、4周,每个时间点5只犬,复查冠状动脉和股动脉,血管造影后取材,分离支架段血管行组织病理观察及计算机图像分析,测量内弹力板面积、管腔面积、内膜增生面积及内膜增生面积百分比。结果 51枚支架成功置入35只犬的冠状动脉和股动脉,各时间点冠状动脉及股动脉造影均证实管腔通畅,无狭窄病变,无血栓形成。组织病理显示,支架置入术后1、3、5 d无内膜增生,仍有支架残留;1周支架完全降解;2周开始出现内膜增生,3周至4周内膜增生相对明显。各时间点均未见明显炎性反应和血栓形成;术后2、3、4周,内膜增生面积分别为(0.04±0.03)mm~2,(0.10±0.03)mm~2,(0.15±0.04)mm~2;内膜增生面积百分比分别为(1.84±1.18)%,(3.72±1.12)%,(6.29±3.36)%,差异有统计学意义(P<0.05)。结论血管内可吸收镁合金支架具有良好的生物相容性,安全有效,易操作,再狭窄程度轻,临床应用前景好。

Experimental novel absorbable magnesium alloy stent

Objective To assess the biocompatibility,efficacy and safty of a self designed and manifactured novel absorbable magnesium alloy stent.Methods An absorbable magnesium alloy stent was implanted into the coronary and femoral artery of 35 hybrid dogs,respectively.The implanted stents were observed by coronary arteriography and femoral arteriography,respectively.The isolated blood vessels in the stent segment were observed by histopathology and their computer images were analyzed on days 1,3,5,7,14,21 and 28 after operation,and five dogs in each group.Results Fifty-one stents were successfully implanted into the coronary and femoral artery of 35 dogs.Coronary and femoral arteriography showed that the stenting vessels were patent with no stenosis and thrombosis.Histopathology showed no intimal hyperplasia but residual stent on days 1,3 and 5 after operation.The stent was completely degraded on day 7 after operation.The intimal hyperplasia was observed on day 14 after operation and became significant on days 21—28.No significant inflammatory reaction and thrombosis were found at different time points after operation. The intimal hyperplasia area was 0.04±0.03 mm~2,0.10±0.03 mm~2 and 0.15±0.04 mm~2,respectively on days 14,21 and 28 after operation,accounting for 1.84%±1.18%,3.72%±1.12% and 6.29%±3.36%,respectively(P<0.05).Conclusion Absorbable magnesium alloy stent is easy to manipulate with a good biocompatibility,efficacy and safety,and is thus of a vast prospect in its clinical application.