Objectives: This study was performed to evaluate the long-term vascular response of the first series of patients treated by a novel ultra-low profile, guidewire-based self-expanding stent system (Sparrow stent) using serial intravascular ultrasound (IVUS).
Background: The long-term vascular response and stent geometry change after self-expanding stent implantation are not known.
Methods: The CARE 1 trial was a single-arm feasibility study of the Sparrow stent in patients with small-vessel disease. Twenty patients were included in this prospective IVUS study, and serial volumetric IVUS analysis was performed after stent implantation and at 6- and 12-months follow up.
Results: Serial volumetric IVUS analysis was available in 13 cases between post-procedure and 6- month follow up and in 6 cases between 6- and 12-month follow up. At 6-month follow up, % neointimal volume was 34 +/- 9%. Stent volume index was increased by 13% , negating part of the luminal loss due to neointimal hyperplasia. There was no correlation between % neointimal volume index and % change in stent volume index (p = 0.7). No additional change occurred in any IVUS parameter between 6 and 12 months after stent implantation.
Conclusions: In this small feasibility study, the use of a novel guidewire-based self-expanding stent was associated with the same degree of neointimal response as that seen with conventional bare-metal stents. Through serial analyses, the IVUS parameters of both the stent and the vessel remained unchanged beyond 6 months after stent implantation.