bFGF及雷帕霉素降解支架对心肌血运重建的实验研究

Experimental Study of Drug-eluting Bioabsorbable Magnesium Stent in Revascularization after Acute Myocardial Infarction

目的探讨镁合金可降解联合bFGF(basic fibroblast growth factor,bFGF)及雷帕霉素(rapamycin)支架对改善心肌缺血区灌注的情况。方法对18只小型猪通过结扎前降支冠状动脉制作急性心肌梗死模型,然后随机分为3组(每组6只),A组为心肌打孔组,B组为心肌打孔+镁合金复合bFGF可降解支架植入组,C组为心肌打孔+镁合金复合雷帕霉素可降解支架植入组。在各组中,于心肌梗死区采用自制高速钻孔器由心外膜打两个直径为2 mm透壁孔道,每个孔道内植入1枚支架。6周后,Image Pro Plus 6.0软件量化各组新生血管密度。于治疗前和治疗后6周SPECT结合软件Emory Cardiac Toolbox分析心肌灌注缺损区域质量百分率,超声学指标左室舒张末直径(LVEDD)、右室收缩末直径(LVESD)、左心室射血分数(LVEF)评价心脏的功能。结果治疗后6周,B组和C组LVEF和心肌灌注质量缺损较A组明显改善(P<0.05);B组和C组中新生血管密度百分率较A组显著改善(P<0.01)。结论镁合金复合bFGF及雷帕霉素可降解支架能够显著增加缺血心肌新生血管密度,改善缺血部位心肌血流灌注,进而提高心脏功能。有望成为一种心肌梗死后再血管化的有效方法。

Objective To investigate the effects of drug-eluting bioabsorbable magnesium alloy stem with basic fibroblast growth factor（bFGF） or rapamycin on myocardial revascularization after acute myocardial infarction. Methods 18 Mini-swines were used to make the animal model by ligation the mid third of left anterior descending（ LAD）, and were randomly divided into transmyocardial drilling revascularization （TMDR） group （ group A, n = 6 ）, transmyocardial drilling revascularization （TMDR） ＋ drug-eluting magnesium alloy stent with bFGF group（ group B, n = 6）, and TMDR ＋ drug-eluting magnesium alloy stent with ra- pamycin group（ C group, n = 6）. In all groups, two transmural channels with 2 mm in diameter were established by using a self- made drilling device, followed by implantation of two stems into the channels. Quantitative analysis of new vessels was performed by Image Pro Plus software six weeks after the operations. The mass defect percent of myocardial perfusion w^is calculated by Em- ory Cardiac Toolbox software. LVEDd, LVEDs and LVEF reflective of cardiac function were measured by echocardiography at pre- treatmem and 6 weeks post-treatment. Results The LVEF and the mass defect percent in group C and group B showed signifi- cant difference as compared with those in A group （ P 〈 0.05 ）. New vessels density was significantly increased in group C and group B than that of group A（P 〈 0.01 ）. Conclusion The drug-eluting bioabsorbable magnesium alloy stent with Heparin and bFGF can increase new vessels density,improve myocardial perfusion and enhance cardiac function, and may be a new method to be widely used in the treatment of revascularization of acute myocardial infarction.