Abstract:

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.