Objective:To observe the cell coverage of the e-PTFE patch

the cellular proliferation and morphologic change of neointima. Methods: Sixteen dogs′ abdominal aorta repaired by e-PTFE patches were taken as specimens at 2

4

8

12

20

28 week after implantation

and the specimens were observed by light microscope

scanning electron microscope and transmission electron microscope. Results: ①Endothelial cells began to appear on the surface of e-PTFE patch at the second week and covered the entire patch surface at the eighth week.②Smooth muscle cell and collagen fibers formed intimal hyperplasia.③The intimal thickening was fast before eight week

but slow after twelve week.④The cells at the anastomotic site continued to proliferate.⑤The neointima over e-PTFE was easy to separate from the material. Conclusion: These results indicate that endothelial cells can cover the surface of e-PTFE patch.The intimal thickening is caused by the proliferation of the smooth muscle cell and collagen.The proliferation might be due to chronic endothelial cell injury

platelet accumulation

hemodynamic change and graft-artery compliance mismatch.