The Research Of External Stent Reducing Long-term-Atherosclerosis Of Autologous Vein Graft In Hypercholesterolemic Rabbit

Objective: To study the long-term protection of external stent to vein graft(VG), and its possible mechanism in hypercholesterolemia; also to provide the experimental evidence to use the external stent in CABG surgery. Methods: Establish a hypercholesterolemic rabbit model and anastomose vein into artery, total cholesterol (TC) was determined timely. Four weeks later, the vein grafts were removed ,and HE staining, P/VB staining , â…§ R:Ag staining, and Oil Red "O" staining were performed. Establish hypercholesterolemic rabbit model of vein grafting with PTFE external stent on one side and unexternal stent on the other side. 12 weeks later, the vein grafts were removed and HE staining, P/VB staining, â…§ R:Ag staining and vascular cell adhesion molecule- 1(VCAM-1) staining were performed. Results: TC achieved a considerable high and stable level, neointimal hyperplasia (NIH) in early stage in VG. External stent promoted vein grafts endothelium remodeling, and reduce NIH, lipid deposition, foam cell, atherosclerosis (AS), and percentage of VCAM-1 staining positive cell in long term of vein grafting. Conclusion: Hypercholesterolemia can accelerate the neointimal hyperplasia in early stage of vein grafts. PTFE can protect vein grafts in hypercholesterolemia and reduce the AS. The possible mechanisms of external stent long-term protective effect include reducing the death of intimal and media cell, reduce CS, promoting angiogenesis, decreasing VCAM-1 positive cell and reducing ECM in neointimal.