title: Bioresorbable vascular scaffold radial expansion and conformation compared to a metallic platform: insights from in vitro expansion in a coronary artery lesion model.
abstract: This study aimed to compare the acute expansion behaviour of a polymer-based bioresorbable scaffold and a second-generation metallic DES platform in a realistic coronary artery lesion model. Experimental mechanical data with conventional methods have so far shown little difference between metallic stents and currently available polymer-based bioresorbable scaffolds (BRS). Nevertheless, differences in acute results have been observed in clinical studies comparing BRS directly with metallic DES platforms.
  
  
  
  We examined the expansion behaviour of the bioresorbable vascular scaffold (3.0×18 mm Absorb BVS; Abbott Vascular, Santa Clara, CA, USA) and a metallic DES (3.0×18 mm XIENCE Prime; Abbott Vascular) after expansion at 37°C using identical coronary artery stenosis models (in total 12 experiments were performed). Device expansion was compared during balloon inflation and after deflation using microscopy to allow assessment of plaque recoil. Minimal lumen diameter (MLD) and minimal lumen area (MLA) and stent eccentricity were quantified from optical coherence tomography (OCT) imaging at nominal diameter and after post-dilation at 18 atm. The MLA in the models with BVS deployed was 4.92±0.17 mm² while in the metallic DES it was 5.40±0.13 mm2 (p=0.02) at nominal pressure (NP), and 5.41±0.20 and 6.07±0.25 mm2 (p=0.02), respectively, after expansion at 18 atm. Stent eccentricity index at the MLA was 0.71±0.02 in BVS compared to 0.81±0.02 in the metal stent at NP (p=0.004), and 0.73±0.03 compared to 0.75±0.02 at 18 atm (p=0.39).
  
  
  
  Results obtained in this in vitro lesion model were comparable to the results in randomised clinical trials comparing BVS and XIENCE stents in vivo. Such models may be useful in future BRS developments to predict their acute response in vivo in eccentric lesions.
authors.affiliation: National Heart Centre Singapore and Duke-NUS Medical School, Singapore.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foin
authors.forename: Renick
authors.initials: R
authors.lastname: Lee
authors.forename: Christos
authors.initials: C
authors.lastname: Bourantas
authors.forename: Alessio
authors.initials: A
authors.lastname: Mattesini
authors.forename: Nicole
authors.initials: N
authors.lastname: Soh
authors.forename: Jie En
authors.initials: JE
authors.lastname: Lim
authors.forename: Ryo
authors.initials: R
authors.lastname: Torii
authors.forename: Jaryl
authors.initials: J
authors.lastname: Ng
authors.forename: Leo Hwa
authors.initials: LH
authors.lastname: Liang
authors.forename: Gianluca
authors.initials: G
authors.lastname: Caiazzo
authors.forename: Enrico
authors.initials: E
authors.lastname: Fabris
authors.forename: Ismail Dogu
authors.initials: ID
authors.lastname: Kilic
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Low
authors.forename: Sukh
authors.initials: S
authors.lastname: Nijjer
authors.forename: Sayan
authors.initials: S
authors.lastname: Sen
authors.forename: Ricardo
authors.initials: R
authors.lastname: Petraco
authors.forename: Rasha
authors.initials: R
authors.lastname: Al Lamee
authors.forename: Justin E
authors.initials: JE
authors.lastname: Davies
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Mario
authors.forename: Philip
authors.initials: P
authors.lastname: Wong
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D020341:Absorbable Implants; D001807:Blood Vessel Prosthesis; D003327:Coronary Disease / Q000601:surgery*; D054855:Drug-Eluting Stents; D020342:Finite Element Analysis; D006801:Humans; D057446:Hydrodynamics; D054457:Tissue Scaffolds