Angiographic and intravascular ultrasonographic findings after endovascular stent implantation

The study was an attempt to evaluate the benefit of intravascular ultrasound imaging (IVUS) as a supplement to follow-up angiography after endovascular stent implantation. A consecutive series of 15 patients underwent stent implantation in the peripheral or coronary arteries. Ten Palmaz stents, 3 Palmaz-Schatz stents and 2 Wallstents were used. After a period from 1 to 6 months (mean 3.2 months) follow-up angiography was performed. In 12 cases the angiography was combined with IVUS of the stent and the adjacent vessel segments. In one case IVUS failed due to the tortuous course of the vessel, in another case the stent was occluded, and in one case IVUS was considered too hazardous. In stents of diameter > or = 5 mm, ultrasound (US) did not reveal more information concerning vessel and stent diameter, stent stenosis and intraluminal surface contact than angiography alone. Smaller stents were insufficiently visualized by conventional radiologic methods. In small stents only IVUS permitted an exact stent identification and differentiation between stent stenosis and stenosis of the native vessel. At US imaging artifacts, caused by the highly reflectant metallic stent struts, interfered with the native vessel wall and partly obscured its structural details.