title: Better inflation time of stent balloon for second-generation drug-eluting stent expansion and apposition: an optical coherence tomography study.
abstract: OBJECTIVE
  We tried to determine the effect of stent balloon inflation time on stent expansion and apposition using optical coherence tomography.
  
  
  BACKGROUND
  Second-generation drug-eluting stents (DES) have thin struts; however, inflation times for optimal stent expansion and apposition are unknown in vivo.
  
  
  METHODS
  Subjects included 17 patients (18 de novo coronary artery lesions), in whom Resolute Integrity → (n = 9) and Xience Prime → (n = 9) DES were deployed. All stents were inflated 3 times to the nominal inflation pressure (8.9 ± 0.6 atm) using the stent delivery balloon. The first inflation continued until the stent was angiographically fully expanded; the other 2 lasted 15 and 30 seconds, respectively.
  
  
  RESULTS
  After the first, second, and third inflation of stent balloon, stent area (5.94 ± 1.7, 6.69 ± 1.8, 7.05 ± 1.8 mm(2) , P < 0.001) and stent volume (146.94 ± 59.40, 166.78 ± 69.55, 177.25 ± 69.19 mm(3) , P < 0.001) increased significantly. The number of malapposed struts (18.0 ± 17.0, 7.9 ± 10.2, 7.4 ± 10.8, P < 0.001) and the mean depth of malapposed struts (188.9 ± 75.6, 120.3 ± 101.4, 95.4 ± 86.8 µm, P < 0.001) decreased. Malapposed stent area (0.62 ± 0.32, 0.52 ± 0.21 mm(2) , P < 0.05) and the malapposed stent volume (15.03 ± 7.78, 12.64 ± 5.16 mm(3) , P < 0.05) decreased significantly following the second inflation; the third inflation gave no additional benefits to these parameters. There was no adverse clinical outcome after each stent balloon inflation.
  
  
  CONCLUSIONS
  Additional 15 seconds of inflation after the angiographically full expansion of the stent balloon allows better stent expansion and apposition even though the inflation pressure is nominal pressure.
authors.affiliation: Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea.
authors.forename: Soe Hee
authors.initials: SH
authors.lastname: Ann
authors.forename: Jae-Wook
authors.initials: JW
authors.lastname: Chung
authors.forename: Cai
authors.initials: C
authors.lastname: DE Jin
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Scot
authors.initials: S
authors.lastname: Garg
authors.forename: Eun-Seok
authors.initials: ES
authors.lastname: Shin
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D041623:Tomography, Optical Coherence