A new vascular polyester prosthesis impregnated with cross-linked dextran.

It is essential that a synthetic vascular graft is preclotting prior to implantation in order to prevent blood leaking through the graft wall. We have impregnated a knitted polyester prosthesis with cross-linked dextran. The aim of this study was to develop a process for obtaining an impervious prosthesis and to compare the characteristics of this dextran-impregnated graft with those of a commercially available collagen-impregnated graft. This new vascular prosthesis was coated with dextran; sodium trimetaphosphate was utilized as the cross-linking agent. In an attempt to determine the optimal conditions for impregnation, the dynamic viscosity of the dextran solution was measured during the cross-linking reaction. The results suggest that the dynamic viscosity is correlated with the concentrations of dextran, sodium hydroxide, and sodium trimetaphosphate. The effect of temperature on the dynamic viscosity was also investigated. The water permeability, the coating weight, and the structure of the dextran-impregnated graft were compared with those of a collagen-impregnated prosthesis. The water permeability of the vascular grafts was reduced by dextran impregnation, from 1010 ml/min per cm2 for the control to 0.04 ml/min per cm2 under standard testing conditions. The dextran coating is capable of rendering the graft impervious to water. The coating weight of the graft treated with dextran was approximately the same as the weight of the collagen-impregnated graft. Finally, the morphology of the prosthetic wall was analyzed using scanning electron microscopy. The promotion of endothelial cell recovery was only observed for the polyester grafts treated with dextran or collagen.