Intimal hyperplasia (IH) is a vessel wall remodeling process responsible of early failure after vascular surgery or endovascular interventions. An ex vivo perfusion was used to study human venous segments regarding functional, histomorphological, immunohistochemical and molecular alterations after 7 (group 1, n = 6) and 14 days (group 2, n = 6) of ex vivo perfusion. All vessel segments showed preserved smooth muscle function before and after perfusion. Histomorphometry revealed IH development which was more pronounced after 14 days rather than 7 days (p < 0.05). Expression of CD34, factor VIII, alpha-actin and MIB-1 was demonstrated in all segments from both groups indicating that muscular and endothelial integrity was preserved after ex vivo perfusion of up to 14 days. PAI-1 mRNA expression was significantly increased after perfusion (p < 0.05), suggesting that the endothelial fibrinolytic function may be modulated in this ex vivo perfusion model of human saphenous veins.