镍钛记忆合金支架堵塞动脉血管的实验研究

An experimental study on occluding arterial blood flow with nitinol alloy stent

６只锥形镍钛形状记忆合金支架经自制导管植入２条犬、４头猪的右侧髂动脉。６个月后犬髂动脉支架段血管几乎完全闭塞，中间只留有１ｍｍ左右的腔隙，８个月后猪的髂动脉支架段血管完全闭塞，远端血管萎缩，支架段相邻的上端血管壁内膜光滑，无炎症细胞浸润和巨细胞反应，支架内形成机化血栓。研究提示：镍钛合金支架与血管的生物相容性良好；锥形血管支架可以完全堵塞动脉，为闭塞异常血管通道提供实验资料和参考。

Abstract To evaluate the occlusion of arteries,6 conic intravascular endoprosthetic stents of titanium-nickel alloy were implanted transcatheterly to right external iliac arteries in 2 normal dogs and 4 normal pigs. The stent was characterised by ductility under 40℃ and restoration memory-shape between 40-46℃.The diameter of the larger site of conic stent was 4. 0 mm in dog and 4. 5 mm in pig.The topographic anatomy showed that the external iliac artery was nearly complete occlusion, with a very small lumen(about 1 mm in diameter)residualized in dogs in 6 months, while complete occlusion in pigs in 8 months. The histopathological examination indicated that the arterial intima in the upper stream of stent was smooth,and neither inflammatory cells infiltration nor foreign giant cell reaction was found.The newly formed granulation tissue inside the stent came from emboli organization.These results suggest that shape-memory alloy stent has good biocompatibility,and conic intravascular endoprosthetic stent might completely occlude the arterial blood flow.