title: New insights on acute expansion and longitudinal elongation of bioresorbable vascular scaffolds in vivo and at bench test: a note of caution on reliance to compliance charts and nominal length.
abstract: OBJECTIVE
  We performed systematic optical coherence tomography (OCT) analyses after bioresorbable vascular scaffolds (BVS) implantation in a "real world" setting aiming at evaluating scaffold expansion and longitudinal integrity.
  
  
  BACKGROUND
  a comprehensive elucidation of BVS acute performance in the "real-world" setting is lacking.
  
  
  METHODS
  acute BVS expansion compared with compliance chart information and longitudinal integrity were assessed in 29 patients (32 lesions) by OCT. In addition, bench experiments with four scaffolds were performed with different combinations of deployment pressures and tube stiffness.
  
  
  RESULTS
  scaffold underexpansion, using compliance chart information as reference, was observed in 97% of OCT cross-sections in vivo; however, only 8.3% of the cross-section analyzed revealed BVS area <5 mm(2) . Calcified plaques were more common in the lowest (9.7%) compared with the mid (8.8%) and highest (6.3%) tertiles of scaffold expansion (P = 0.003 and P = 0.001 for lowest vs. mid, and lowest vs. highest, respectively). Seventeen (54.8%) scaffolds were elongated during implantation, but no signs of scaffold fracture were revealed. Elongation and impaired expansion were reproduced in the bench testing when the scaffold was deployed with high pressure in a hard tube.
  
  
  CONCLUSIONS
  compliance chart information should not be used to predict final BVS dimensions in the clinical setting. While BVS expansion could be potentially impaired by calcified plaques, they may elongate during deployment. Bench experiments confirmed the elongation phenomenon when BVS were deployed with high pressure in hard tubes.
authors.affiliation: Division of Cardiology, Ferrarotto Hospital, University of Catania, Catania, Italy; Department of Interventional Cardiology, Pitangueiras Hospital, Jundiai, Sao Paulo, Brazil; Harrington Heart and Vascular Institute, University Hospitals, Case Medical Center, Cleveland, Ohio.
authors.forename: Guilherme F
authors.initials: GF
authors.lastname: Attizzani
authors.forename: Yohei
authors.initials: Y
authors.lastname: Ohno
authors.forename: Davide
authors.initials: D
authors.lastname: Capodanno
authors.forename: Bruno
authors.initials: B
authors.lastname: Francaviglia
authors.forename: Carmelo
authors.initials: C
authors.lastname: Grasso
authors.forename: Carmelo
authors.initials: C
authors.lastname: Sgroi
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Fujino
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ganocy
authors.forename: Giovanni
authors.initials: G
authors.lastname: Longo
authors.forename: Claudia I
authors.initials: CI
authors.lastname: Tamburino
authors.forename: Marilena
authors.initials: M
authors.lastname: Di Salvo
authors.forename: Alessio
authors.initials: A
authors.lastname: La Manna
authors.forename: Piera
authors.initials: P
authors.lastname: Capranzano
authors.forename: Corrado
authors.initials: C
authors.lastname: Tamburino
mesh_terms: D020341:Absorbable Implants; D000368:Aged; D003187:Compliance; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000628:therapy*; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D058226:Plaque, Atherosclerotic; D011312:Pressure; D011474:Prosthesis Design; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D061205:Vascular Calcification / Q000175:diagnosis / Q000628:therapy*
keywords: bioresorbable vascular scaffolds; elongation; expansion; optical coherence tomography