AngioplastyвЂ™s Fight against Restenosis: Drug Eluting Stents & Bare Metal Stents Balloon Angioplasty вЂў minimally invasive treatment to open blocked arteries. вЂў Within this procedure, a balloon catheter is employed to enlarge a narrowed vessel lumen stenosis. вЂў have shown increased coronary arterial lumen diameter, increased coronary blood flow, and decreased chest pain. Diagram of Angioplasty Procedure What is Restenosis? вЂў the re-narrowing of a coronary artery after dilation Coronary Angioplasty has been performed. вЂў six months after the procedure restenosis typically affects between 25% to 45% of patients within results in a repeat procedure. вЂў Restenosis is also considered an exaggeration of вЂњvascular healingвЂќ and вЂњremodelingвЂќ that probably occurs to some degree in all cases Restenosis of Balloon Angioplasty Fighting Restenosis вЂў Prior to the mid 1990вЂ™s, balloon angioplasty was the primary treatment of arteriosclerosis вЂў In the mid 1980's, radiologists and cardiologists worked on solutions to reduce restenosis rates; вЂў rotational polishers, tiny shavers, and lasers, to be delivered via catheters. Bare Metal Stents вЂў are small expandable metal tubular structures that support the vessel wall and maintain blood flow through the opened vessel (5). вЂў In 2001, 84% of the 1,000,000 percutaneous coronary interventions were treated with stents. Of those million, 20% or 200,000 patients develop in-stent restenosis History of the Bare Metal Stent вЂў The first stent was inserted into a human coronary artery by European researchers in 1986, in France, by Julio Palmaz and Richard Schatz. вЂў Julio Palmaz and Richard Schatz, lead to the first stents to be approved in the United States in 1994 вЂў The first company to produce a coronary artery stent was Cordis, a Johnson & Johnson company, in 1994. Early Palmaz-Schatz stent Stenting Diagram Neointimal Hyperplasia вЂў is an abnormal increase in the number of cells causing a thickening of the intima of a blood vessel. вЂў caused by platelets that are attracted by the damaged tissue caused by the placement of a stent. вЂў tissue grows through the openings in the stent and eventually narrows the lumen of the vessel, therefore, reducing myocardial blood flow. вЂў This restenosis leads to a repeat procedure. Restenosis of Bare Metal Stents вЂў Prevalent in 10 to 30% of patients who receive bare metal stents . вЂў usually eliminate abrupt closures, but typically result in a restenosis rate of 25% six months after being placed. вЂў The majority of restenosis occurring after a bare metal stent is placed usually occurs within 30 days. Diagram of Reoccurring Restenosis Drug Eluting Stents The invention of the drug-eluting stent came into the angiographic procedures in 2002. The three major elements of drug-eluting stents are: вЂў Stent вЂў Drug вЂў The mechanism for controlling drug release (usually a polymer to protect and control release) Two Main Types of Drug Eluting Stents 1.Cordis CYPHER sirolimus-eluting stent (April of 2003) 2.Boston Scientific TAXUS paclitaxel-eluting stent system (March of 2004) вЂў Both stents have shown benefits toward reducing restenosis rates up to 9% Cordis CYPHER Sirolimus-eluting stent вЂў Sirolimus is a drug used to help prevent the body from rejecting organ and bone marrow transplants. вЂў it helps to limit normal tissue overgrowth (restenosis) following coronary stent implantation. вЂў The polymer allows the drug to be released over 30 days which decreased restenosis effects. вЂў Since the FDA approval it is estimated that almost 450,000 of these stents have been implanted in 300,000 U.S. patients Cypher stent which uses Sirolimus Boston Scientific TAXUS Paclitaxel-eluting stent вЂў The drug Paclitaxel is an antineoplastic agent that inhibits cell migration and proliferation вЂў coated with a polymer chemical compound called Transulte (also known as SIBS). вЂў The Boston Corporation : Taxus I-VI studies. вЂў These clinical trials have shown that paclitaxeleluting stents reduce restenosis and the need for revascularization with a neutral effect on mortality and myocardial infarction risk. Taxus Stent which uses Paclitaxel Controversy Arises with the use of Drug-Eluting Stents вЂў Drug eluting vs. Bare metal stent. вЂў Research shows that the revascularization rate for bare metal stents is only 12 to 14 percent. вЂў It is said that the financial impact is not with the patient, but it is the hospital taking the biggest loss. (stage the procedure, ethical or not) вЂў Drug eluting stents are about 2,000 dollars more than bare metal stents. (decrease $ for repeated procedures and decrease in surgery) вЂў An Economical Analysis (Cincinnati network of hospitals) вЂ“ 3 million dollars in costs to the provider or to the hospital for every 1000 treated patients. The Future of Angioplasty and Restenosis вЂў It is estimated that 800,000 to 900,000 individuals in the United States undergo some kind of percutaneous coronary intervention annually. Most of the procedures involve stenting. вЂў Drug eluting stent research seems to be at the tip of the ice berg. вЂў As studies progress, it will be clearer to health care providers of the details and benefits of the use drug eluting stents or bare metal stents.