Laboratory Research On The Correlation Between TGF-β1、AT1R And Inhibitory Effect Of Polydioxanone Suture External Stent On The Vein Graft Neointima Thickening

[Objective]To evaluate the effect of a biodegradable external stent on intimal vein graft thickening in a arteriovenous bypass grafting model, and study its possible mechanism.[Methods]①Twenty-four rabbits underwent carotid interposition bypass via ipsilateral jugular vein. Half received the polydioxanone suture external stent(PDS) and half a simple vein graft(control).Group subsets received external stent removal or sham-control exploration at4th and12th week. Then observe the neointima thickening of vein graft.②Each of the specimens was detected for pathological and molecular biological examination.[Results]①At4th and12th week the PDS group had significantly less medial and intimal thickening than the control group(p<0.05),and there were fewer proliferating smooth muscle cells and extra cellular matrix formation in the PDS group than the control group at every interval.②The angiotensin Ⅱ type1receptor(AT1R) were over-expressed mostly in adventitia in PDS group,while the transformation growth fator-β1(TGF-β1) was expressed mostly in PDS group.[Conclusion]An macro-porous nonrestrictive, PDS external stent can effectively inhibit te intimal hyperplasia in vein bypass grafts, which might due to the formation the new extima promoting of angiogenesis、chemotaxis inflammation factors、re-distribution of TGF-β1and AT1R.