西罗莫司对减轻小口径移植血管材料内膜增生的作用

Effect of Sirolimus on reducing the small diameter of graft intimal hyperplasia of materials

目的:将脱细胞联合肝素处理的小口径异种移植血管进一步结合西罗莫司,以观察术后移植血管内膜增生的情况。方法:将脱细胞联合肝素处理的犬颈动脉进一步结合西罗莫司,并分为A组(对照组,脱细胞并结合肝素)和B组(西罗莫司组,脱细胞并结合肝素+西罗莫司处理)两组。取健康家兔16只,随机分为两组(每组8只),利用兔颈动脉旁路移植模型,分别移植A组和B组的血管进行比较。术后分别于1、2、4、8周采血采用HPLC法检测B组移植血管中西罗莫司的含量。术后3个月超声检测移植血管通畅情况,并取血管样本经免疫组织化学和HE染色观察内膜增生程度。结果:B组8周后仍可检测到西罗莫司,且含量呈逐渐降低趋势。术后3个月超声显示,A组部分血管(2/8)斑块形成、管腔狭窄,B组血管无明显狭窄(P<0.05)。免疫组织化学检测显示,A、B两组血管管壁均可见新生的内皮细胞和平滑肌细胞。HE染色提示,B组内膜增生程度较A组轻[A、B两组内膜/中膜厚度比分别为(1.63±0.04)μm、(0.43±0.04)μm](P<0.05)。结论:在脱细胞结合肝素的小口径异种移植血管上进一步结合西罗莫司可以有效减轻内膜增生。

Objective： To observe the effect of intimal hyperplasia, Sirolimus was integrated in the decellularized and heparinized small-caliber vascular xenograft. Methods： The decellularized and heparinized canine carotid arteries were further integrated with Sirolimus, and were divided into Group A （Control group, deeellularized and heparinized） and Group B （Sirolimus group, decellularized and heparinized ＋ Sirolimus treatment）. Sixteen rabbits were randomly divided into two groups （Group A and B, n=8）. The grafts of two groups were transplanted respectively into the rabbits, using the rabbit carotid artery bypass grafting model. The content of Sirolimus was measured by HPLC at l, 2, 4, and 8 week in Group B, respectively. Results： Sirolimus was found in vascular wall of Group B at 8 week after implantation, and the content of Sirolimus declined during the 8 weeks. After 3 months ultrasound showed that plaque fol^nation and vessel stenosis were found in some blood vessels of Group A （2/8）, while Group B had no significant vessel stenosis （P〈O.05）. Immunohistochem- istry showed endothelial cells and smooth muscle cells were found in Group A and B. HE stain found that the intimal hyperplasia was lighter in Group B than Group A [thickness ratio of intima to media in two groups were （1.63±0.04） p.m, （0.43±0.04） μm] （P〈0.05）. Conclusion： Sirolimus can reduce intimal hyperplasia in the decellularized and heparinized small-caliber vascular xenograft.