title: [Frequency and characteristics of incomplete stent apposition during and after sirolimus-eluting stent implantation].
abstract: OBJECTIVE
  Incomplete stent apposition (ISA) is frequently observed after sirolimus-eluting stent (SES) implantation. This study investigated the incidence, morphological features, and possible mechanisms of this phenomenon.
  
  
  METHODS
  Fifty-two lesions in 47 eligible patients were treated with SES and serial intravascular ultrasound (IVUS) assessment at the time of post-intervention and 8-month follow-up. ISA was carefully identified from the IVUS images of these lesions. Specifically, quantitative two dimensional IVUS analysis was performed if the lesions demonstrated ISA, including routine IVUS parameters as well as other measurements related to ISA.
  
  
  RESULTS
  Overall, ISA was observed in 13 lesions (25.0%) at follow-up. Persistent ISA (n = 6, 11.5%), defined as ISA consistently observed both at post-intervention and follow-up, and late-acquired ISA (n = 7, 13.5%)were systematically compared. Eighty-three percent of cases of persistent ISA were located around the stent edges, whereas all cases of late-acquired ISA were in the stent body. In the persistent ISA group, no serial changes were observed in the lumen area or external elastic membrane area (EEMA) from post-intervention to follow-up. However, in the late-acquired ISA group, EEMA and lumen area significantly increased from post-intervention to follow-up (EEMA: 13.4 +/- 3.2 vs 17.6 +/- 3.3 mm2, respectively, p < 0.0001 ; lumen area: 6.7 +/- 1.4 vs 9.2 +/- 1.8 mm2, respectively, p = 0.004). No adverse clinical events were observed in either group.
  
  
  CONCLUSIONS
  ISA was frequently observed during and after SES implantation in clinical practice. No clinical disadvantages were observed during 16 month clinical follow-up periods. Positive remodeling may potentially cause late-acquired ISA.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Morino
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujibayashi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hashida
authors.forename: Yota
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Naoko
authors.initials: N
authors.lastname: Tsumuraya
authors.forename: Nami
authors.initials: N
authors.lastname: Okamoto
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nagaoka
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ikari
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Tanabe
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D020099:Coated Materials, Biocompatible; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011475:Prosthesis Failure; D020123:Sirolimus; D015607:Stents / Q000009:adverse effects; D018084:Ultrasonography, Interventional