自制被覆聚氨酯膜与非覆膜不锈钢支架在动脉系统应用的实验对照研究

Experimental Contrast Study of Homemade Noncovered and Covered Polyurethane Stent Used in Arterial System

目的 探讨自制覆膜与非覆膜Z型不锈钢支架在动脉系统中应用的可行性。方法 本实验共用 9条健康杂种犬 ,按观察时间随机分为 3组 (3条 /组 )。应用介入放射学方法分别将自制Z SSS支架 9枚和PU SSS支架 11枚置入犬的腹主动脉。实验动物分别于支架置入后 2周、4周、12周行血管造影复查。处死实验动物 ,行组织学检查并进行统计学分析。结果 9枚Z SSS和 10枚PU SSS成功置入靶血管。Z SSS和PU SSS的管腔开通率分别为 :10 0 %和 2 7.2 7% ,两者具有显著的统计学差异 (P =0 .0 0 1)。支架置入 4周时 ,两种支架表面内皮化基本完成。PU SSS引起的局部血栓形成、炎性反应和平滑肌细胞增生明显。 2周、4周、12周时 ,两种支架新生内膜厚度分别为 (3 5 9.2 3± 5 0 .15 ) μm、(4 4 0 .87± 5 8.3 8)μm、(5 81.2 8± 12 1.2 5 ) μm和 (178.49± 14 .67) μm、(12 0 2 .79± 42 1.0 5 ) μm、(14 66.0 6± 463 .19) μm ,两者具有显著差异 (P <0 .0 1)。 4周时 ,平滑肌细胞增殖细胞核抗原 (PCNA)阳性细胞率分别为 :(4 6.0 7± 14 .73 ) %和 (85 .2 3± 18.2 5 ) % ,两者具有显著的差异 (P <0 .0 1)。扫描电镜 :12周时支架表面内皮细胞成熟。置入 12周的支架金属丝表面光洁 ,未见腐蚀现象。结论 ①Z SSS具有良好?

Objective To study the feasibility of two kinds of homemade stent used in arterial system and to spread their clinical application. Methods Nine healthy hybrid canines were included in our study. Twenty prostheses,nine Z type stainless steel stent (Z SSS) and eleven Z type stainless steel stent covered polyurethane (PU SSS) were placed in canines' abdominal aorta. Following up angiography was performed at 2 weeks,4 weeks and 12 weeks respectively after placement to observe the shape of vascular lumen and blood flow of collateral vessel. All animals were sacrificed according to grouping time. Prostheses were removed for histopathological examination. Measurement data was analyzed by t test. Enumeration data was analyzed by χ 2 test. Results All except one stent were placed successfully in target vessels. The patency rates of Z SSS and PU SSS were 100% and 27.27%,respectively,with significant statistical difference ( P =0.001). Two weeks,4 weeks and 12 weeks after the stent placement neointimal thicknesses of Z SSS and PU SSS were (359.23±50.15)μm,(440.87±58.38)μm,(581.28±121.25)μm and (178.49±14.67)μm,(1202.79±421.05)μm,(1466.06±463.19)μm,respectively,with significant statistical difference ( P <0.01). Positive cell rate of proliferating cell nuclear antigen (PCNA) of SMC of both stents was (46.07±14.73)% and (85.23±18.25)%,respectively,at 4 weeks after placement,with significantly statistical difference ( t =6.535, P <0.01). Endothelialization of both stents reached about 100% at 4 weeks after placement. Scanning electron microscopic examination indicated that endothelium on the surface of stents became mature at 12 weeks. Surface erosion of stainless stents struts was not found. Conclusion ①Z SSS compared with PU SSS has better mechanical behavior,physiochemical stability,anticoagulative capability and biocompatibility. It was an ideal intraarterial stent. ②PU SSS is not fit for clinical application at present.