title: Intravascular ultrasound analysis of small-vessel lesions treated with novel ultra-low profile, guidewire-based self-expanding stent system.
abstract: OBJECTIVE
  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.
authors.affiliation: Center for Cardiovascular Technology, Stanford University Medical Center, Stanford, CA 94305-5637, USA.
authors.forename: Bon-Kwon
authors.initials: BK
authors.lastname: Koo
authors.forename: Masao
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: Alexandre
authors.initials: A
authors.lastname: Abizaid
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Whitbourn
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006801:Humans; D011446:Prospective Studies; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional