Dressing Up the Palmaz-Schatz Stent

Abstract

We are approaching the 20th anniversary of the first use of coronary balloon angioplasty in humans. This nonsurgical treatment of obstructive coronary atherosclerosis has proved effective in relieving subjective and objective manifestations of myocardial ischemia, with recent clinical trials demonstrating comparability with coronary artery bypass surgery in selected patients with advanced multivessel disease (References 1 through 5 and personal observations). Despite impressive technical refinements of equipment and technique, balloon angioplasty continues to be plagued by three major limitations: (1) inability to treat certain types of coronary lesions, particularly those presenting as chronic total occlusion; (2) the potential of acutely aggravating coronary obstruction by means of coronary dissection, spasm, or thrombosis necessitating emergency coronary bypass surgery or causing myocardial infarction; and (3) recurrence of coronary narrowing 3 to 6 months after initial treatment. New devices have been developed in response to these shortcomings. Directional atherectomy can remove a component of the obstructive atherosclerotic plaque, but clinical superiority over conventional balloon angioplasty has been questioned.6 7 8 High-speed rotational atherectomy drills plaque and allows treatment of certain coronary narrowings that cannot be treated with a balloon catheter and appears to enhance the effectiveness and safety of conventional angioplasty for patients with complex lesions.9 10 11 Efforts are ongoing to determine whether debulking lesions alone or in conjunction with balloon angioplasty will reduce the chance of lesion recurrence.12 Devices such as direct laser angioplasty, laser-heated balloon angioplasty, and extraction atherectomy have been shown to be feasible techniques, but their marginal utility has been null or minimal. Coronary stents, percutaneously deployed metallic endovascular prostheses, have had a substantial impact on improving the immediate and late outcomes of patients treated with balloon angioplasty. The first evidence of efficacy was demonstrated by the Gianturco-Roubin stent that is based on a continuous-coil design. This …