Cellular reaction to the Vascugraft polyesterurethane vascular prosthesis: in vivo studies in rats

The biocompatibility of Vascugraft, a polyesterurethane vascular prosthesis manufactured by Braun-Melsungen AG, was assessed by immunofluorescence and histological studies. Discs, 1 cm2, of Vascugraft prosthesis were implanted into the peritoneal cavity of rats. Results were compared with Impra, GORE-TEX and Mitrathane prostheses and a control group. Animals were killed at 1, 2, 6, 9 and 12 wk. Total T cells, T helper cells, T suppressor cells and activated T lymphocytes expressing Interleukin-2 receptors were quantified by a cytofluorometric technique in the peripheral blood of rats. For each period of implantation, all vascular prostheses showed no significant change in the percentage of total T cells, T subsets and T cells expressing Interleukin-2 receptors when compared to the control group. Histological examination of the tissue reaction surrounding the Vascugraft revealed a mild inflammatory reaction, similar to the one observed with both polytetrafluoroethylene grafts. However, the rate and the degree of encapsulation were different between grafts. The Vascugraft prosthesis was well encapsulated 2 wk after implantation, whereas inhibition of fibroblastic proliferation into the graft wall and surrounding both polytetrafluoroethylene grafts was observed for each period of implantation. The Mitrathane prosthesis exhibited a moderate inflammatory response, characterized by a high level of activation on fibroblasts compared to other grafts.