[De-endothelialization and re-endothelialization in autogenous vein grafts--fundamental and clinical study]

Preparation for preserving endothelial cells (ECs) of autogenous vein grafts (AVGs) and the process of de-endothelialization (de-E) and re-endothelialization (re-E) were studied. Jugular veins (n = 31) from mongrel dogs were immersed in saline solution (SS), heparinized blood (HB), and other three kinds of solution. Then jugular veins (n = 26) immersed in SS for 3 hours, were used for AVGs to the abdominal aorta. Intimal changes were observed by scanning electron microscopy. ECs showed irreversible changes about 60 minutes after immersion in SS and about 150 minutes in HB. Eleven (92%) of 12 graft specimens within 1 day after implantation showed wide areas of de-E, while ECs on the venous valve were satisfactorily preserved in 6 (55%) of 11 valves. Re-E was observed predominantly around the valve from 3 days after implantation, and completed within 3 weeks. Clinically, specimens in 35 AVGs were collected before anastomosis. Severe EC damage was observed in 23 (66%) of them. Long-term observation revealed graft stenosis in 2 due to intimal hyperplasia (IH) in grafts with severely damaged EC. These results suggest that venous valves are an important source of re-E, and that the preservation of ECs in graft preparation is an important factor to prevent IH.