Local release of metal ions from endovascular metallic implants in the human biological specimens: An overview of in vivo clinical implications

Cardiovascular heart disease is one of the leading healthcare problems in this present era and need much care to prevent from this problem. The main reason for this problem is the accumulation of fats or plaque that blocks coronary arteries of heart which in turn resist the flow of blood to the heart walls and cause serious complications. The advancement in biomedical engineering and fabrication technology along with implantation technique made it possible and convenient to minimize the problems of coronary heart diseases. Small medical implantable metallic devices are used in contemporary cardio logical practice. Metals constitute the main components of these cardiovascular medical devices. A complication to the intervention and especially to bare metal stents is in-stent restenosis. Furthermore, limited information is available regarding the condition of stent surfaces and their interaction with vascular tissue following implantation. Corrosion of stents presents two main risks: release of metal ions into tissue and bodily fluids and deterioration of the mechanical properties of stents which may contribute to fracture. Release of metal ions could alter the local tissue environment leading to up-regulation of inflammatory mediators and promote in-stent restenosis. In this article we have reviewed studies that have characterized in vivo corrosion of cardiovascular metallic devices which is associated with release of metal ions into tissue and bodily fluids. This review further reports a possible association between stents and metal contact allergy. Potential clinical consequences of these observations are discussed.