Biocompatibility between stent graft and abdominal aorta

To evaluate the biocompatibility between the domestic stent-graft and abdominal aorta.Methods We made stent-graft with felting of expanding-polytetra- fluroethylene (ePTFE) graft and nitinol stent.They were implanted in the subrenal abdominal aorta.The specimes were taken out 2,4,12 weeks afterwards and underwnet HE/special pigmentation of collagen and elastin,immunohistochemistry of α actin from vascular smooth muscle cells(VSMC),in-situ apoptosis detection and scan of electromicroscopy.The comparison between them and normal abdominal aorta in intimal thickness,relative content of collagen and elastin,density and apoptosis ratio of VSMC in medium was made through the image analysis.Results The stent-graft was covered with intima as early as 2 weeks but suffered more severe intimal hyperplasia all the time (P<0.01).The morphology and distribution of collagen and elastin were generally normal in the experimental group (P>0.05).However,its density and apoptosis ratio of VSMC in medium were significantly higher than in the normal ones (P<0.01) in 2,4 weeks.Conclusion The stent-graft shared fine biocompatibility with the abdominal aorta except for the significant intimal hyperplasia.3 refs.