Thierry B, Merhi Y, Bilodeau L, Trépanier C, Tabrizian M
Department of Biomedical Engineering, McGill University, Montreal , QC, Canada.
Biomaterials. 2002 Jul;23(14):2997-3005. doi: 10.1016/s0142-9612(02)00030-3.
Acute and subacute stents thrombosis along with thrombus mediating neointimal proliferation within the stent struts remain major concerns in coronary stenting. Up to date, there is an obvious lack of data on the thrombogenicity of stent materials in physiological conditions. This study was performed to compare the relative thrombogenicity of nitinol versus stainless steel stents. Nitinol stents were laser cut to reproduce the exact geometry of the stainless steel Palmaz stents and tested in an ex vivo AV shunt porcine model under controlled conditions. Nitinol stents presented only small amounts of white and/or red thrombus principally located at the strut intersections while Palmaz stents clearly exhibited more thrombus. As a result, 125I-fibrin(ogen) adsorption and (111)I-platelets adhesion were significantly lower on nitinol than on stainless steel devices (36%, p = 0.03 for fibrin(ogen) and 63%, p = 0.01 for platelet). These results were confirmed by scanning electron observations showing different thrombus morphologies for nitinol and stainless steel. Along with the unique mechanical properties of nitinol, its promising haemocompatibility demonstrated in our study may promote their increasing use for both peripheral and coronary revascularization procedures.
急性和亚急性支架血栓形成，以及血栓介导支架小梁内的新生内膜增生，仍然是冠状动脉支架置入术中的主要问题。到目前为止，在生理条件下关于支架材料血栓形成倾向的数据明显不足。本研究旨在比较镍钛合金支架与不锈钢支架的相对血栓形成倾向。将镍钛合金支架进行激光切割，以重现不锈钢Palmaz支架的确切几何形状，并在体外可控条件下的猪动静脉分流模型中进行测试。镍钛合金支架仅出现少量主要位于小梁交叉处的白色和/或红色血栓，而Palmaz支架明显出现更多血栓。结果，镍钛合金上的125I-纤维蛋白（原）吸附和（111）I-血小板黏附显著低于不锈钢装置（纤维蛋白（原）为36%，p = 0.03；血小板为63%，p = 0.01）。扫描电子观察显示镍钛合金和不锈钢的血栓形态不同，证实了这些结果。除了镍钛合金独特的机械性能外，我们的研究中所展示的其良好的血液相容性可能会促进其在周围血管和冠状动脉血运重建手术中越来越多地被使用。
