Cardiovascular devices vascular stents

The regeneration of normal filament structure of restored tissues was observed by immunohistochemical methods after PHB devices implantation [66]. The immunohistochemical demonstration of cytokeratine, an intermediate filament, which is a constituent of epithelial and mesodermal cells, agreed with observations on intact mesothelium. Heparin sulfate proteoglycan, a marker of basement membrane, was also identified [66]. However, in spite of good tissue reaction to implantation of cardiovascular PHB patches, PHB endovascular stents in the rabbit iliac arteria caused intensive inflammatory vascular reactions [80]. 

Vascular grafts and patches, as well as heart valves, are among the oldest of cardiovascular implants. More recently, permanent internal devices include pacemakers, defibrillators, stents, left ventricular assist devices, and artificial hearts. 

Biomaterials have played a vital role in the treatment of cardiovascular diseases, examples of applications including heart valve prostheses, vascular grafts, stents, indwelling catheters, ventricular assist devices, total implantable artificial heart, pacemakers, automatic internal cardioverter defibrillator, intraaortic balloon pump, and more. A key requirement for materials in cardiovascular applications, particularly blood-contacting devices, is blood compatibility, that is, nonthrombogenic. Additional requirements include mechanical and surface properties that are application specific. Surveying the field of polymers used in cardiovascular applications reveals that PUs, polyethylene terephthalate (PET), and expanded PTFE (ePTFE) are the most commonly used. This section will review each of the three polymers followed by a brief introduction of other emerging polymers for use in the cardiovascular area. 

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