[Histological character of intimal hyperplasia post jugular vein grafts and the protective effect of lovastatin].

Objective: To investigate the characteristics of intimal hyperplasia and lovastatin's effects on canine jugular venous prosthesis bypass grafting.

Methods: In the study, 12 adult mistus dogs were randomly divided into 2 groups: lovastatin group and control group. All the dogs were performed with jugular venous prosthesis bypass grafting (ePTFE, 6 mm in diameter, and 5 cm in length). Four weeks later, all the 12 specimens were harvested. The patency and mural thrombus of grafts were evaluated. The characteristics of intimal hyperplasia were described and measured by HE staining and endothelial nitric oxide synthase (eNOs) immunohistochemical method. The differences between the two groups were compared.

Results: Four weeks later, 3 grafts with complete occlusion were found in the two groups separately. Apparent intimal hyperplasia was observed in all the grafts. The neointima of proximal and distal part in lovastatin group were thinner than in control group respectively (proximal P=0.045, distal P=0.040). The endothelial cells were found in the surface of neointima. Newly born vessels could be found in the neointima and the new vessels were more in lovastatin group than in control group (proximal P=0.041, distal P=0.031).

Conclusion: At the end of 4 weeks, the intimal hyperplasia with neovascularization was obviously near the anastomosis. Lovastatin showed the ability to inhibit the intimal hyperplasia and promote the neovascularization.