Neointimal fibrous hyperplasia (NFH) at the anastomosis of prosthetic vascular grafts is a major cause of the graft occlusion. Because a factor of NFH is early thrombus formation at the anastomosis, anticoagulat and fibrinolytic agents were studied of the effectiveness. Inner diameter 6mm Gore-Tex grafts were implanted in 26 mongrel dogs. These dogs were devided to four groups (control, heparin, urokinase, heparin+urokinase).
Two weeks after implantation, the thrombus thickness at the anastomoses were measured. The mean values were 125 in control, 52μ in heparin, 48μ in urokinase, 20μ in heparin+urokinase. 3 months after implantation, when endothelial cells covered the inner surfaces, the mean values of the neointimal thickness were 460μ in control, 325μ in heparin+urokinase.
Heparin and urokinase reduced the thrombus formation at the anastomoses, but did not prevent NFH so prominently. We thought that the proliferative procedure by myofibroblasts must be modified to prevent NFH.
