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目的 :了解聚—消旋乳酸—乙醇酸 (PLGA)涂层支架置入冠状动脉后损伤处的愈合过程。方法 :用摩尔比 60∶40的消旋乳酸与乙醇酸共混聚合浸涂Dragon支架制成PLGA涂层支架作为涂层组 ,Dragon支架作为对照组 ,支架置入小型猪冠状动脉 ,7日期与 1个月期各 8只猪 ,每只置入两枚支架。支架置入前、后、终点时行冠状动脉造影 ,处死动物后分离取出支架置入段冠状动脉 ,固定并制备标本行扫描电子显微镜 (SEM )观察与组织学检查。结果 :7日期 1只于支架置入右冠状动脉后 3h、左冠状动脉前降支后 1 5h时死亡 ,组织学示损伤后 1 5h已经有血细胞附着 ,3h见到纤维素附着。所有支架置入成功。SEM示 7日期两组均完全内皮化 ,制备标本时撕裂处见内皮下为纤维素。组织学示 7日期对照组 2支、涂层组 1支支架血管段形成血栓 ;7日期内膜组织成份主要为附着的纤维素 ,偶见到平滑肌细胞、纤维母细胞 ,表面为一层内皮细胞 ,两组间无差异 ;1个月期内膜组分主要为纤维素样肌性组织及细胞外基质 ,内膜增生的程度两组间无差异。各组 1个月期内膜均较 7日期的明显增厚。结论 :冠状动脉损伤 +支架置入后的愈合过程为 ,血小板附着于损伤处→纤维素附着→内皮细胞与中层平滑肌细胞移行、增生 ,内膜增生。纤维素附着可能是内皮化的基础。猪
OBJECTIVE: To investigate the healing process of poly (D, L-lactide-co-glycolide) (PLGA) -coated stents after implantation into the coronary artery. Methods: The PLA stent was coated with Dragon scaffolds by dipolymerization of glycolic acid and racemic lactic acid with a molar ratio of 60:40 to form a coating group. The Dragon scaffold was used as a control group. The scaffolds were implanted into miniature pig coronary arteries. One month each of eight pigs, each placed in two stents. Coronary angiography was performed before, after, and at the end of stent placement. The animals were sacrificed and the stent-graft coronary arteries were removed. The specimens were fixed and prepared for scanning electron microscopy (SEM) and histological examination. Results: On the 7th day, only 3h after the stent was inserted into the right coronary artery and 15h after the left descending anterior descending coronary artery, the histology showed that the blood cells were attached 15h after the injury and the cellulose attachment was seen in 3h. All stents inserted successfully. The SEM showed complete endothelialization in both groups on day 7, and cellulose under the endothelium at the tear site when preparing the specimen. Tissue showed 7 days in the control group 2, the coating group a stent blood vessel thrombosis; 7 days the main component of the membrane tissue attached to the cellulose, and occasionally see the smooth muscle cells, fibroblasts, the surface of a layer of endothelial cells , There was no difference between the two groups; within 1 month, the main component of the membrane-like muscle-like tissue and extracellular matrix, the degree of intimal hyperplasia was no difference between the two groups. Each group within 1 month of the membrane were significantly thicker than the 7th. CONCLUSION: The healing process after coronary artery injury and stent implantation is that the platelets attach to the lesion site, the attachment of cellulose, the migration of endothelial cells and middle smooth muscle cells, hyperplasia and intimal hyperplasia. Cellulose attachment may be the basis of endothelialization. pig