ABSTRACT
The immunogenicity and biocompatibility of biomaterials used as blood vessel conduits were assessed by the quantification of blood T lymphocyte subsets (T helper and T suppressor cells), using a cytofluorometric technique and by light microscope observation. One cm2 disc of grafts made from woven polyester (Dacron®), expanded polytetrafluoroethylene (ePTFE), and woven polyester whose luminal surface was coated with a tetrafluoroethylene plasma, were implanted in the peritoneal cavities of rats. Animals were sacrificed at 1, 2 and 6 weeks post-implantation. At 1 week, the percentage of T helper cells and T suppressor cells in the woven polyester and ePTFE groups were significantly lower than in the control group (wounded rats). Moreover, the ratio T helper/T suppressor cells at 1 week was found to be higher in the woven polyester (p = 0.04) and in the ePTFE group (p = 0.03) when compared to the ratio of the control group. At 2 and 6 weeks, no difference in the percentage of T cell subsets was observed for all groups. Pathological examination showed a severe inflammatory reaction to woven polyester grafts and plasma TFE polyester grafts, while a moderate reaction to ePTFE grafts was observed.
