聚酯纤维部分覆膜血管内支架兔主动脉内置入及其与主动脉壁间组织学愈合的实验研究

目的 建立小型动物兔主动脉内聚酯纤维部分覆膜支架微创置入的动物模型并研究覆膜支架置入后聚酯纤维覆膜材料与兔主动脉壁间的组织学愈合.方法 应用6F血管长鞘为输送系统,在12只雄性日本大白兔主动脉中分别置入3枚聚酯纤维部分覆膜支架.2周时进行主动脉造影随访支架位置及主动脉通畅情况,然后处死摘取带覆膜支架处主动脉分别进行大体观察和显微镜下组织学观察与分析.结果 部分覆膜聚酯纤维支架兔主动脉内置入术技术成功率为83.3%(10/12).处死后大体观察未见覆膜支架移位,剖开动脉壁可见聚酯纤维部分覆膜支架的金属支架部分及聚酯纤维织物部分均被新生发亮的组织覆盖.血管腔内未见明显的大块血栓形成.显微镜下组织学观察见聚酯纤维覆膜材料与动脉壁间有不连续的新生内膜形成.在新生组织的血管腔侧可见不连续的内皮化.吞噬了聚酯纤维的异物巨细胞和巨噬细胞提示存在与覆膜材料相关的炎症反应.结论 聚酯纤维部分覆膜血管内支架可被安全,成功地应用微创介入技术置入体型较小的兔降主动脉内,聚酯纤维覆膜材料与兔主动脉壁间组织愈合情况良好.

Partially covered stent-graft implantation in the aorta of rabbits for experimental study of the stent-graft healing

Objective To develop a technique of endovascular placement of handmade partially covered polyester stent-grafts in rabbit aorta for experimental study in small animals. At the same time, we investigated graft healing in porous polyester fabric after a short implantation period. Methods A Z-stent with 12 struts 10 mm in length and 7 mm in diameter made from the inner core of a guide wire was partially covered with a polyester graft. Each was delivered in turn with a 6 French sheath in the descending aorta of 12 male Japanese white rabbits. Three stent-grafts were implanted in each rabbit. At 2 weeks, all the implants of the survived rabbits were angiographed and harvested for macroscopy and microscopy. Partially covered stent-graft implantation in the aorta of rabbits for experimental study of the stent-graft healing. Results The procedures were successfully performed in 10 rabbits. The technical success rate was 83.3%. All stent-grafts remained patent and none migrated. Gross luminal examination showed that both the metal parts of the stent and the polyester graft material were completely covered with thin transparent tissue without massive thrombosis. H&E staining revealed incomplete neointima formation between the stent-graft and aorta and incomplete linear endothelial cells on the luminal side of tissue ingrowth into the stent-graft. Foreign body giant cells and macrophages represented inflammatory reactions related to the graft material. EVG staining revealed that the media was compact where the stent struts compressed the aortic wall. Conclusion Partially covered polyester stent-grafts can be placed in relatively small animals safely and potentially used in animal research. Polyester grafts interact with the healthy aortic wall of rabbits reasonably well.