Environmental influences on endovascular stent platelet reactivity: an in vitro comparison of stainless steel and gold surfaces.

Thrombosis is an initiating reaction to vascular injury that follows the placement of vascular devices. Platelets play a crucial role in this response. Their interaction with endovascular devices is not solely a function of device properties, but a multifaceted response dependent on several biological factors that interact in the context of a hemodynamic environment. We sought to investigate the role of local environmental variations on determining indices of biocompatibility. Using a recently described in vitro flow apparatus, we separately studied the platelet and coagulative component responses to stainless steel endovascular stents with and without gold coating. When allowed to interact, these biological mediators of thrombosis enabled varied biocompatibility outcomes in a manner that was dependent on flow. Using platelet reactivity as an index, the stainless steel faired better under some conditions, while under other conditions, gold was superior. Considering such impacts of local environment on biocompatibility is important, both in the interpretation of experimental findings, as well as the continued use and optimized development of vascular devices. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 186-193, 2004