新型地塞米松-肝素双涂层支架在小型猪动脉损伤模型中预防支架内再狭窄的实验研究

Preventive effect of a novel dexamethasone-heparin coated stent on restenosis in a porcine artery injury model

目的:评价新型植物源蛋白包载的地塞米松-肝素双涂层支架在小型猪血管损伤模型中近期抑制支架内再狭窄的有效性和安全性。方法:32只小型猪随机分入A组(裸支架组)、B组(玉米醇溶蛋白zein涂层支架组)、C组(肝素涂层支架组)、D组(地塞米松-肝素双涂层支架组)。各组均包括4周观察终点的猪3只和12周观察终点的猪5只。每只猪于双侧股动脉各置入同种支架1枚。至观察终点时复查血管造影并处死取材,通过形态学方法观察内膜增生及炎症情况。结果:4周时,各组血管损伤平均积分分别为2.10±0.58、2.23±0.52、2.33±0.57和2.25±0.64(P>0.05),损伤相近。管腔面积分别为(2.68±1.28)(、2.59±1.31)、(2.85±0.86)和(3.21±1.09)mm2(P<0.05),D组最大。平均内膜厚度分别为(295±138)、(309±79)、(245±101)、(103±64)μm(P<0.05),D组最小。炎症积分D组较其他3组明显降低(P<0.05)。12周时各组内膜增生均较前加重,D组管腔面积及新生内膜增生仍优于另外3组,其他各指标差异均无统计学意义。结论:采用植物源蛋白包载的地塞米松-肝素双涂层支架可以有效而安全地抑制健康小型猪支架置入术后4周和12周时的内膜增生,预防支架内再狭窄。

Objective:To evaluate the efficacy and safety of a novel corn-protein-zein coated dexamethasone-heparin-eluting stent in preventing in-stent restenosis in a porcine artery injury model.Methods:Thirty two mini-pigs were randomly divided into group A(bare stent group),group B(corn-protein-zein coated stent group),group C(heparin coated stent group) and group D(dexamethasone heparin double coated stent group).Each group contained 3 pigs for 4-week follow-up and 5 pigs for 12-week follow-up.Each pig was implanted two same kinds of stents in the bilateral-femoral artery.Animal underwent angiographic study and histomorphometric analysis at 4 and 12 weeks.Results:At 4th week,mean injury scores were similar in the four goups(2.10±0.58,2.23±0.52,2.33±0.57 and 2.25±0.64,respectively,P>0.05).Goup D had the largest luminal area [(3.21±1.09) mm2,P<0.05] and the least neointimal thickness [(103±64) μm,P<0.05] among all the groups,while there were no statistical differences among groups A,B and C in luminal area [(2.68±1.28) mm2,(2.59±1.31) mm2,and(2.85±0.86) mm2,respectively] and neointimal thickness [(295±138) μm,(309±79) μm,and(245±101) μm,respectively].The inflammation scores in goup D were significanly smaller than those in Goup A,B and C(P<0.05),no statistical differences existed among other groups.At 12th week,the neointimal proliferation was progressing in all groups,but group D still had a clear advantage in luminal area and neointimal thickness.Conclusion:The dexamethasone-heparin coated stent could effectively and safely inhibt neointimal proliferation and prevent in-stent restenosis 4 weeks and 12 weeks after implantation in a porcine artery injury model.