猪冠状动脉内金属支架蛋白涂层的生物相容性研究

The Biocompatibility of Protein Coating Applied to Metallic Stent

目的：评估蛋白涂层金属支架植入冠状动脉的生物相容性和致血栓性，并通过造影及病理学检查以确定其对动脉壁的影响。方法：金属支架由３１６Ｌ医用不锈钢丝编织而成，将该支架浸入含有交联剂的明胶溶液一定时间后，经干燥制成蛋白涂层。将蛋白涂层支架固定在３．０ｍｍ经皮冠状动脉腔内成形术（ＰＴＣＡ）球囊上，通过８Ｆ大腔引导导管植入１３只小型猪冠状动脉前降支中段。结果：１１只动物支架被成功植入前降支中段，２只动物支架植入前死于心室颤动。支架植入后３天及７天造影证实管腔通畅，无血栓形成、充盈缺损、夹层、栓塞、支架移位或血管痉挛。扫描电镜显示３天时有少量血小板沉积和纤维蛋白形成，且部分内皮化。７天时完全内皮化。４只动物在２８天造影时管腔通畅。支架植入节段的所有管腔狭窄直径均＜５０．０％，平均狭窄直径为（３０．０±７．２）％，无闭塞发生。组织病理学检查显示：所有支架植入节段完全内皮化，有不同程度的新生内膜增生，无异物巨细胞聚集，局部管壁完整，无中层坏死。平均新生内膜厚度为０．３３±０．１７ｍｍ，平均新生内膜面积为０．４１±０．３１ｍｍ２，平均百分狭窄面积为（３２．０±２１．０）％。结论：在小型猪冠状动脉模型中，通过球囊导管系统植入蛋?

Objective:To assess the biocompatibility and thrombogenicity of crosslinked protein coating of the metallic stent. Methods:Metallic stent was woven by 316 L medical stainless steel.The coating of metallic stent was made by immersing the stent in gelatin solution containing crosslinker and then air dried.The coated stents mounted on 3.0 mm percutaneous transluminal coronary angioplasty balloon and implanted in the left anterior descending (LAD) of coronary arteries through 8F guiding catheter in 13 mini swine. Results:The stents were successfully implanted into the middle segment of LAD in 11 animals.Two animals died of ventricular fibrillation before stenting.Angiography revealed that the vessels were patent 3( n =3)and 7( n =4)days after stent implantation,without evidence of thrombosis,filling defects,dissection,embolization,stent migration or vessel spasm.At the 3rd day,scanning electron microscope and histopathologic examination showed minimal platelet deposition,fibrin formation and partial endothelialization on the stent,at the 7th day complete endothelialization developed.At the 28th day coronary angiography( n =4) demonstrated vessel patency and diameter stenosis <50.0%[mean diameter stenosis was (30.0±7.2)%],without occlusion,histopathologic examination revealed complete endothelialization at the site of stent implantation and a variable degree of neointimal proliferation.There were no large collection of foreign body giant cells,no medial necrosis,local vascular integrity was maintained. Mean neointimal thickness and neointimal areas were 0.33±0.17 mm and 0.41±0.31mm 2,respectively.Mean percentage area stenosis was (32.0±21.0)%. Conclusion:In the mini swine model,protein coated stent can be easily implanted into coronary artery by balloon catheter. There was no serious local vascular tissue reaction.The coating of the stent has good biocompatibility without thrombogenesis.