Development of intimal hyperplasia in six different vascular prostheses

Objectives: to compare six vascular prostheses for the development of intimal hyperplasia (IH) in a sheep model. Material and methods: prostheses tested were gelatin sealed Dacron (GSD), fluoropassivated Dacron (FPD), Fluropassiv(TM) (FD), expanded polytetrafluoroethylene (ePTFE), carbon-lined expanded polytetrafluoroethylene (CL-ePTFE) and vascular access graft (VAG). Sixty-two adult female;Merino sheep (35-45kg) were used. Elliptical graft patches were implanted into the left common carotid artery using one of the six graft types: GSD (n = 10), FPD (n = 10), FD (n = 12) VAG (n = 10), ePTFE (n = 10), or CL-ePTFE (n = 10). Four weeks later grafts were removed for histopathological assessment and measurement of the degree of III obtained on a computerised image analysis system. Results: IH indices were significantly less for FPD (0.191 +/- 0.095, p < 0.05), FD (0.199 +/- 0.081, p < 0.05), ePTFE (0.213 +/- 0.078, p < 0.05) and CL-ePTFE (0.161 +/- 0.066 p < 0.01), compared to the GSD group (0.287 +/- 0.077), The VAG group (0.257 +/- 0.091) showed no difference compared to GSD. There was no significant difference between the FPD, FD, ePTFE and CL-ePTFE grafts. Conclusion: this study indicates that less IH occurred in the two-ePTFE grafts and two fluoropolymer coated Dacron grafts than in gelatin sealed Dacron or polyurethane grafts.