title: [Implications of late expansion of self-expanding stents on neointimal response: a serial study with intravascular ultrasound].
abstract: OBJECTIVE
  A unique property of self-expanding stents is the continuous force exerted against the vessel wall, which may induce additional arterial damage with implications on restenosis. The main purpose of this study is to evaluate the consequences of late self-expansion of coronary Wallstents.
  
  
  METHODS
  Eleven patients with Wallstents implanted in native coronary arteries, in whom baseline, post-stenting, after high pressure balloon inflation and at 6-month follow-up intravascular ultrasound were performed. The stented segments were divided in 2-mm cross-sections, that were analyzed independently and carefully matched at each situation using anatomic landmarks. Multiple regression analysis was performed.
  
  
  RESULTS
  Late expansion was present in 93% of the studied sections (mean increase in stent area of 2.0 1.9 mm2) and was clearly related to stent oversizing (r = 0.45; p < 0,0001). Although late expansion was a significant positive predictor of neointimal growth (r = 0.63; p < 0.0001), it showed a negative correlation with late luminal loss (r = 0.33; p < 0.0001). No significant correlation was found between optimization of angiographic results with high pressure inflations and late luminal loss.
  
  
  CONCLUSIONS
  Late expansion is a common phenomenon after Wallstent implantation and is mainly determined by stent oversizing. Despite the fact that this phenomenon is associated with greater neointimal proliferation, it seems to have a net beneficial effect on late luminal loss.
authors.affiliation: Servicio de Cardiología Intervencionista, Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Sanmartín
authors.forename: Javier
authors.initials: J
authors.lastname: Goicolea
authors.forename: Fernando
authors.initials: F
authors.lastname: Alfonso
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Alex
authors.initials: A
authors.lastname: Flores A
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Ortiz
authors.forename: Camino
authors.initials: C
authors.lastname: Bañuelos
authors.forename: Rosa Ana
authors.initials: RA
authors.lastname: Hernández-Antolín
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D023903:Coronary Restenosis / Q000000981:diagnostic imaging; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015607:Stents; D013997:Time Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional
vernacular_title: Implicaciones de la expansión tardía de los stents autoexpandibles sobre la respuesta neointimal: estudio seriado con ecografía intravascular.