犬外周动脉内植入雷帕霉素-肝素洗脱支架的组织病理学研究

Study on histopathology of the china-made drug-eluting stent with sirolimus-heparin placed in the peripheral artery:an experimental study in dogs

目的探讨国产雷帕霉素-肝素洗脱支架(DES)植入犬外周动脉的组织病理学特点。方法28枚支架(12枚雷帕霉素-肝素支架,8枚雷帕霉素支架和8枚裸支架)分别植入14只犬外周动脉中。30天后对7只犬进行造影观察后处死,另7只犬60天后造影观察后处死,剖开并取出支架段动脉,观察支架段动脉有无血栓形成、出血、坏死及炎性改变,计算支架段动脉内膜厚度、内膜面积、平滑肌细胞分数、纤维蛋白分数和内皮化分数,并对数据进行统计分析。结果30天时雷帕霉素-肝素支架和雷帕霉素支架无内膜增生,含极少量平滑肌细胞,较多量纤维蛋白沉着,无或仅有极少内皮细胞覆盖;裸支架无内膜增生,含多量平滑肌细胞,极少量纤维蛋白,无或极少内皮细胞覆盖;三组之间在平滑肌细胞分数,纤维蛋白分数上有差别,差别有统计学意义(P<0.01)。60天时雷帕霉素-肝素支架无内膜增生,含少量平滑肌细胞,较多量纤维蛋白沉着,无或仅有极少内皮覆盖;雷帕霉素支架无内膜增生,含少量平滑肌细胞,较多量纤维蛋白沉着,无或仅有极少内皮覆盖,2枚支架内大量血栓形成;裸支架内膜增生较重,含大量平滑肌细胞,极少量纤维蛋白,较多内皮细胞覆盖;三组之间在内膜厚度、内膜面积、平滑肌细胞分数、纤维蛋白分数、内皮化分数上有差别,差别有统计学意义(P<0.01)。结论国产雷帕霉素-肝素支架可以抑制内膜增生,具有一定抗凝能力。

Objective To evaluate the histopathological characteristics of the china-made sirolimus-heparin eluting stent placed in the dog＇s peripheral arteries. Methods A total of 28 stents （12 sirolimus-heparin eluting stents, 8 sirolimus stents and 8 bare stents） were implanted into peripheral arteries of 14 dogs. Seven dogs were killed after 30 days, the others were killed after 60 days. The stented-arteries of 14 dogs were dissected and observed focusing on the thrombosis, hemorrhage, necrosis and inflammation, and the neointimal thickness, neoinitial area, intimal endothelialization score, initial fibrin content, initial smooth muscle cell content were calculatedand statistically analyzed. Results At 30 days, the siroli- mus-heparin stent and sirolimus stent had no initial hyperplasia, but small quantity of smooth muscle cells, large quantity of fibrins and a little of endothelial cells. The bare stent had a large quantity of smooth muscle cells, a little fibrins and a little of endothelial cells without initial hyperplasia. At 60 days, the sirolimus-heparin stent had no initial hyperplasia, small quantity of smooth muscle cells, large quantity of fibrins, a little endothelial cells. The sirolimus stent had no initial hyperplasia, while small quantity of smooth muscle cells, large quantity of fibrins, a little of endothelial cells and thrombosis were observed in 2 stents. The bare stent had initial hyperplasia, large quantity of smooth muscle cells and endothelial cells, and a little of fibrins. At 30 days, there were statistic significant differences in initial l fibrin content and initial smooth muscle cell content among sirolimus-heparin stent, sirolimus stent and bare stent （P〈0.01）. At 60 days, significant differences were found among sirolimus-heparin stent, sirolimus stent and bare stent in the neointimal thickness, neointimal area, initial endothelialization score, initial fibrin content and initial smooth muscle cell content （P〈0.01）. Conclusion The china-made peripheral arterial sirolimus-heparin eluting stent may inhibit initial hyperplasia and had the ability of anticoagulation.