Development of intimal hyperplasia in six different vascular prostheses

Abstract

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 IH 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.