Intracoronary stenting during percutaneous transluminal coronary angioplasty.

A flexible, balloon-mounted, coil stent was developed to address the problems of acute closure and long-term restenosis, which currently limit the safety and efficacy of percutaneous transluminal coronary angioplasty. The device is made of 0.006-in. stainless steel suture material and is mounted on balloons, 2.5-4.5 mm in diameter, for use in the coronary circulation. Results of studies in canine coronary arteries have demonstrated long-term patency and stability, and studies in the atherosclerotic arteries of rabbits have suggested late results with stenting that might be superior to those obtained with balloon angioplasty alone. Initial clinical studies have focused on the use of the device as a "bridge" to surgery if closure occurs. The stent appears to have been successful in this application. A phase 2 study is now examining the stent as definitive therapy for acute closure in certain anatomic subsets of patients. Information on long-term patency is pending. If this is favorable, the device will be studied to see if it reduces the incidence of restenosis in the subset of patients in whom balloon dilatation alone fails to produce an optimal hemodynamic result.