Coronary stenting and inflammation Stent coronário e inflamação

coronary artery disease has dramatically altered the practice of coronary artery bypass grafting surgery. New complications caused by percutaneous coronary interventions (PCI) with the implantation of stents has emerged and affected the result when surgery is subsequently required. The stent was initially utilized for the treatment of complications associated with percutaneous coronary angioplasty, specifically acute occlusion and restenosis. Employed as support, an expanded metallic mesh impedes the phenomenon of 'recoil', one of the factors responsible for genesis of post-angioplasty restenosis. However, recent evidence has demonstrated that the coronary stent may induce the appearance of Systemic Inflammatory Response Syndrome (SIRS) [1,2], where restenosis after stent implantation constitutes the earliest manifestation of an inflammatory reaction. SIRS, the consequent endothelial dysfunction and ischemia are events that follow and are little understood. The inflammatory reaction triggered by the insertion of the stent is caused and maintained by the following factors: 1 expansion of the stent with rupture of the atherosclerotic plaque and the tunica media 2 maintenance of the radial pressure of the stent on the arterial wall 3 the presence of a metallic foreign body 4 ischemic phenomenon induced by endothelial dysfunction The implantation and expansion of the stent determines a coronary vascular injury that is very much more severe to the lesion produced by balloon angioplasty. This follows the concept of "the bigger the better", initially suggested by KUNTZ et al. [3] where the high dilation pressure [4], in which the expansion of the stent creates the greatest luminal diameter possible, causes severe structural alterations to the wall of the coronary artery. Figure 1 demonstrates the severity of the lesion caused on the arterial wall by the expansion of the stent with the rupture of the atherosclerotic plaque and the tunica media. SPECIAL EDITORIAL