三种不同材质与不同构型静脉内支架的实验研究

Experimental study of three kinds of intravenous stents with different materials and different types

目的 优选一种性能良好的静脉内支架 ,以推广至临床应用。方法 将 3种静脉内支架置入犬体内 ,按分组时限 (置入后 2周、4周、8周、6个月、9个月 )定期处死动物 ,处死前行血管造影 ,处死后取支架区血管行组织学检查 (包括大体病理、光镜、扫描电镜 ) ,观察支架的性能、开通情况及内皮化过程。计量资料用方差分析及q检验 ,计数资料用 χ2 检验 ,半计量资料用Ridit分析。结果不锈钢 (国产Z形支架 )、记忆合金 (国产网状支架 )、镀金支架 (国产Z形支架 )的移位率分别为 :13 3%、13 3 %、7 7% ,差异无显著性意义 (χ2 =0 2 81,P =0 86 9) ;展开不全率分别为 :6 7%、46 7%、0 0 % ,差异具有显著性意义 (χ2 =12 194,P <0 0 1,其中记忆合金支架与不锈钢支架比较 ,χ2c=4 2 6 7,P <0 0 5 ,与镀金支架比较 ,精确检验 ,P =0 0 0 5 4) ;属支静脉开通率分别为 :72 7%、35 7%、5 5 6 % ,差异无显著性意义 (χ2 =3 42 1,P =0 181) ;血栓形成程度经Ridit分析 ,差异无显著性意义 ( R值 95 %可信限分别为 0 30 49～ 0 5 33 8,0 430 6～ 0 72 13,0 370 8～ 0 6 399,P >0 0 5 ) ;开通率分别为 :93 3%、6 6 7%、84 6 % ,差异无显著性意义 (χ2 =3 6 49,P =0 16 1)。支架置入静脉后

Objective To select a kind of stent with better property and spread its clinical application. Methods Three kinds of stents including “Z” type stainless steel stent(SSS), mesh Ni Ti alloy stent(AS), and gild stent(GS) were placed into dogs′ vena cava. Angiography was performed 2 weeks, 4 weeks, 8 weeks, 6 months, and 9 months after stent placements (according to the grouping time), then the animals were sacrificed to get the veins with stents for histopathology examinations (including macro pathology, microscope and scanning electron microscope). Data of displacement rate, expand rate, patency rate of stents, patency rate of tributary veins, endothelial thickness, and course of endothelialization were acquired to indicate stent application property. Measurement data were analyzed by analysis of variance and q test. Enumeration data were analyzed by χ 2 test. Ranked data were analyzed by Ridit analysis. Results The displacement rates of SSS, AS, and GS were 13 3%, 13 3%, and 7 7%, respectively(χ 2=0 281, P =0 869); The incomplete expanding rates of SSS, AS, and GS were 6 7%, 46 7%, and 0.0% respectively. There was statistical difference(χ 2=12 194, P <0 01. AS contrast to SSS,χ 2 c=4 267, P <0 05, contrast to GS, P =0 005 4); Patency rates of tributary vein were 72 7%, 35 7%, and 55 6%, respectively. There was no difference among the patency rates of the tributary veins of the three types of stents(χ 2 =3 421, P =0 181); There was no difference among the thrombosis states of the three types of stents( P >0 05); The patency rates of SSS, AS, and GS were 93 3%, 66 7%, and 84 6%, respectively. There was no statistical difference among the rates(χ 2 =3 649, P =0 161). Endothelialization reached about 100% 4 weeks after the stents placements. Desquamating of GS plating layer was found 4 weeks after stent placement, surface erosion of SSS wire and AS wire was not found in 9 months. Conclusion Z type stainless steel stent has better anticoagulative capability, anticorrosive capability, and biocompatibility, and it is now an ideal intravenous stent.