Abstract
Percutaneous transluminal coronary angioplasty (PTCA) with stent implantation is widely used for the treatment of coronary stenosis. However, restenosis after stent implantation frequently reported by intravascular ultrasound evaluation. This may occur because of the reduced luminal area after implantation, insufficient stent expansion, or by the elastic recoil of the stent (ERS). Quantitative evaluation of stent expanding should provide further information on how to decrease the incidence of re-stenosis. Many previous studies have observed stent properties in 2D. However, the stent geometry is changed in 3D space, and 3D measurements will provide further information on factors such as the risk for asymmetric ERS. We performed 3D reconstruction using high spatial resolution images obtained with a Micro-CT system to observe the 3D expansion behavior of a test stent and quantitatively evaluate ERS. The expansion behavior of each structural component of the stent varied, as did the ERS and eccentricity. ERS ranged from 2.4% to 9.2% during observation form proximal and distal positions in each component. The greatest difference in ERS between 2D and 3D measurements was 5.2%. 3D measurements provide more information on ERS than 2D measurements. Our result shows the importance of the observation, and the evaluation by three dimensions.