title: Computational fluid dynamics applied to virtually deployed drug-eluting coronary bioresorbable scaffolds: Clinical translations derived from a proof-of-concept.
abstract: BACKGROUND
  Three-dimensional design simulations of coronary metallic stents utilizing mathematical and computational algorithms have emerged as important tools for understanding biomechanical stent properties, predicting the interaction of the implanted platform with the adjacent tissue, and informing stent design enhancements. Herein, we demonstrate the hemodynamic implications following virtual implantation of bioresorbable scaffolds using finite element methods and advanced computational fluid dynamics (CFD) simulations to visualize the device-flow interaction immediately after implantation and following scaffold resorption over time.
  
  
  RESULTS
  CFD simulations with time averaged wall shear stress (WSS) quantification following virtual bioresorbable scaffold deployment in idealized straight and curved geometries were performed. WSS was calculated at the inflow, endoluminal surface (top surface of the strut), and outflow of each strut surface post-procedure (stage I) and at a time point when 33% of scaffold resorption has occurred (stage II). The average WSS at stage I over the inflow and outflow surfaces was 3.2 and 3.1 dynes/cm(2) respectively and 87.5 dynes/cm(2) over endoluminal strut surface in the straight vessel. From stage I to stage II, WSS increased by 100% and 142% over the inflow and outflow surfaces, respectively, and decreased by 27% over the endoluminal strut surface. In a curved vessel, WSS change became more evident in the inner curvature with an increase of 63% over the inflow and 66% over the outflow strut surfaces. Similar analysis at the proximal and distal edges demonstrated a large increase of 486% at the lateral outflow surface of the proximal scaffold edge.
  
  
  CONCLUSIONS
  The implementation of CFD simulations over virtually deployed bioresorbable scaffolds demonstrates the transient nature of device/flow interactions as the bioresorption process progresses over time. Such hemodynamic device modeling is expected to guide future bioresorbable scaffold design.
authors.forename: Bill D
authors.initials: BD
authors.lastname: Gogas
authors.forename: Boyi
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Mathematics and Computer Science, Emory University, Atlanta, Georgia.
authors.forename: Tiziano
authors.initials: T
authors.lastname: Passerini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Veneziani
authors.forename: Marina
authors.initials: M
authors.lastname: Piccinelli
authors.forename: Gaetano
authors.initials: G
authors.lastname: Esposito
authors.forename: Emad
authors.initials: E
authors.lastname: Rasoul-Arzrumly
authors.affiliation: Andreas Gruentzig Cardiovascular Center, Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Mosaab
authors.initials: M
authors.lastname: Awad
authors.forename: Girum
authors.initials: G
authors.lastname: Mekonnen
authors.forename: Olivia Y
authors.initials: OY
authors.lastname: Hung
authors.forename: Beth
authors.initials: B
authors.lastname: Holloway
authors.forename: Michael
authors.initials: M
authors.lastname: McDaniel
authors.forename: Don
authors.initials: D
authors.lastname: Giddens
authors.forename: Spencer B
authors.initials: SB
authors.lastname: King
authors.forename: Habib
authors.initials: H
authors.lastname: Samady
keywords: bioresorbable scaffolds; computational fluid dynamics; virtual modeling