Re-endothelialisation in autogenous vein grafts

Objectives: To clarify the course of re-endothelialisation (Re-E) in an entire graft and to establish the effect of immersion media for the preservation of endothelial cells. Methods: Autogenous femoral veins of dogs were immersed in heparinised saline solution (n=18) or heparinized autogenous blood (n=18). After immersion, the grafts were implanted into bilateral femoral artery, and were retrieved 1 day to 4-8 weeks after implantation. Results: For the grafts immersed in the heparinised saline solution, the values for % area of endothelial cell coverage before implantation, and at 1 day, 1 week, and 4 weeks after implantation were 44.9%, 6.2%, 14.5%, and 81.3%, respectively For the grafts immersed in heparinised autogenous blood, the values were 73.5%, 20.6%, 79.2% and 95.5%, respectively. However, such relatively rapid speed of Re-E slowed down considerably after 1 week following implantation in this group. Conclusions: The use of heparinized autogenous blood is strongly recommended as a preparation media for autogenous vein grafts. Almost all of the endothelial cells fall away in the earlier period after implantation and regenerate multifocally and irregularly. Re-E is incomplete even at 8 weeks after surgery, and we suggest that the area of incomplete Re-E may develop into intimal hyperplasia.