Intracoronary ultrasound observations during stent implantation.

T he Palmaz-Schatz stent has been used successfully to improve primary angioplasty results, to treat large coronary dissections, or to prevent impending closure of the lumen.-1-5 The determination of successful stent implantation is based on the angiographic appearance. However, angiographic projection imaging may not reveal the three-dimensional geometry that is necessary to appreciate full expansion of a cylindrical meshwork device such as the intracoronary stent. Intravascular ultrasound (IVUS) imaging has the advantage of providing detailed cross-sectional images from within the vessel lumen, allowing better evaluation of stent expansion.16-21 Based on angiographic assessment, it has been recommended to overdilate the stenosis about 10% greater than the reference vessel diameter.1 There is no quantitative guideline for IVUS assessment of successful stent implantation. The purpose of this study was to compare the observations of IVUS with standard angiography after stent implantation and to develop recommendations for guiding stent implantation by IVUS.