A NEW METHOD FOR MEMBRANE CONSTRUCTION ON EPTFE VASCULAR GRAFTS - EFFECT ON SURFACE-MORPHOLOGY AND PLATELET-ADHESION

Vascular grafts made of expanded polytetrafluoroethylene (ePTFE) are w idely employed in reconstructive surgery. Despite their successful use for replacement of large diameter blood vessels, ePTFE vascular graft s with internal diameters of less than 6 mm uniformly fail as a result of blood clot formation. To reduce the ePTFE reactivity to platelets, a new method for membrane construction on the inner graft surface was developed. The membrane, made of a chitosan-poly(vinyl alcohol) blend and non-ionic detergent, is constructed by adsorption of a thin liqui d film and air drying. The chemically modified ePTFE surface exhibits both morphological changes and a markedly reduced reactivity to platel ets in in vitro studies. Chemical activation of the chitosan-poly(viny l alcohol) blend, to trigger desired protein binding, may yet serve as a complementary surface modification approach. (C) 1997 John Wiley & Sons, Inc.