可降解性聚乙醇酸血管外支架抑制移植静脉内膜的增生

背景：冠状动脉旁路移植后，自体大隐静脉桥的再狭窄是急需解决的问题。国内外研究已表明，应用血管外支架是预防再狭窄的一种可行办法。目的：以犬双侧后腿股静脉-股动脉旁路移植动物模型为基础，观察可降解性聚乙醇酸血管外支架抑制移植静脉内膜增生的作用。 方法：24只草犬随机抽签法分为3组，对照组直接进行双侧后腿股动脉移植，聚乙醇酸外支架组移植静脉后外套聚乙醇酸外支架，涤纶外支架组移植静脉后外套非限制性非可降解材料(涤纶)外支架。移植后4，6周取出移植静脉，测量其内膜、中膜的厚度。同时检测增殖细胞核抗原与血管内皮生长因子，计算其细胞增殖情况与滋养血管生长情况。结果与结论：聚乙醇酸外支架和涤纶外支架均与移植静脉壁之间形成了富含毛细血管的新生外膜，移植静脉中膜及内膜厚度均小于对照组(P < 0.05)；中膜血管内皮生长因子表达显著降低(P < 0.05)，而外膜血管内皮生长因子表达显著增高(P < 0.05)，中膜增殖细胞核抗原表达显著降低(P < 0.05)。聚乙醇酸外支架组移植静脉中膜及内膜厚度小于涤纶外支架组(P < 0.05)，增殖细胞核抗原阳性细胞数低于涤纶外支架组(P < 0.05)。提示可降解性聚乙醇酸血管外支架在血管移植后可以明显抑制移植静脉内膜和中膜增生，进而预防移植静脉再狭窄，是一种良好的可用于抑制移植血管再狭窄的外支架材料。

Degradable polyglycolic acid extravascular stent inhibits intimal hyperplasia of vein graft

BACKGROUND: The restenosis of autologous great saphenous vein bridge after coronary artery bypass graft surgery is a hot potato. It has been proved that the extravascular stents are effective in preventing restenosis.OBJECTIVE: To observe the influence of the degradable polyglycolic acid (PGA) extravascular stent on preventing intimal hyperplasia of vein graft based on animal model of femoral vein-artery bypass in canine bilateral hind legs.METHODS: Totally 24 claydogs were randomly divided into 3 groups. Control group was directly transplanted with femoral vein graft in dog bilateral hind legs. PGA stent group was transplanted with femoral veins and PGA stents. Dacron stent group was transplanted with femoral veins and dacron stent. At 4 and 6 weeks postoperation, the vein grafts were removed, then the tunica media and intima thickness was measured. Vascular endothelial growth factor and proliferating cell nuclear antigen were detected, to calculate cell proliferation and nourishing vessel growth.RESULTS AND CONCLUSION: New exosporium which was abundant in blood capillaries grew up between vein stents and vein grafts. The tunica media and intima in the vein grafts were thinner than that in control group (P < 0.05). The expression of tunica media vascular endothelial growth factor significantly reduced (P < 0.05), while the expression of adventitia vascular endothelial growth factor significantly increased (P < 0.05). The expression of tunica media proliferating cell nuclear antigen significantly reduced (P < 0.05). The tunica media and intima thickness in vein graft of PGA stent group was less than that in dacron stent group (P < 0.05), the amount of proliferating cell nuclear antigen positive cells was lower than that in dacron stent group (P < 0.05). The degradable PGA extravascular stent can obviously inhibit the tunica medial and intimal hyperplasia of vein graft, thus preventing the restenosis of vein grafts, it is a good stent material for inhibiting vein graft restenosis.