title: Over-expansion capacity and stent design model: An update with contemporary DES platforms.
abstract: BACKGROUND
  Previously, we examined the difference in stent designs across different sizes for six widely used Drug Eluting Stents (DESs). Although stent post-dilatation to larger diameter is commonly done, typically in the setting of long tapering segment or left-main PCI, there is an increasing recognition that information with regard to the different stent model designs has a critical impact on overexpansion results. This study aims to provide an update on stent model designs for contemporary DES platforms as well as test overexpansion results under with oversized post-dilatation.
  
  
  RESULTS
  We studied 6 different contemporary commercially available DES platforms: Synergy, Xience Xpedition, Ultimaster, Orsiro, Resolute Onyx and Biomatrix Alpha. We investigated for each platform the difference in stent designs across different sizes and results obtained after post-expansion with larger balloon sizes. The stents were deployed at nominal diameter and subsequently over expanded using increasingly large post dilatation balloon sizes (4.0, 5.0 and 6.0mm at 14ATM). Light microscopy was used to measure the changes in stent geometry and lumen diameter after over-expansion. For each respective DES platform, the MLD observed after overexpansion of the largest stent size available with a 6.0mm balloon was 5.7mm for Synergy, 5.6mm for Xience, 5.2mm for Orsiro, 5.8mm for Ultimaster, 5.5mm for 4mm Onyx (5.9mm for the 5mm XL size) and 5.8mm for BioMatrix Chroma.
  
  
  CONCLUSIONS
  This update presents valuable novel insights that may be helpful for careful selection of stent size for contemporary DES based on model designs. Such information is especially critical in left main bifurcation stenosis treatment where overexpansion to larger oversized diameter may be required to ensure full stent apposition.
authors.affiliation: National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore.
authors.forename: Jaryl
authors.initials: J
authors.lastname: Ng
authors.affiliation: National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore. Electronic address: Nicolas.foin@gmail.com.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foin
authors.affiliation: National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore.
authors.forename: Hui Ying
authors.initials: HY
authors.lastname: Ang
authors.affiliation: National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore.
authors.forename: Jiang Ming
authors.initials: JM
authors.lastname: Fam
authors.affiliation: International Centre for Circulatory Health, NHLI, Imperial College London, UK.
authors.forename: Sayan
authors.initials: S
authors.lastname: Sen
authors.affiliation: International Centre for Circulatory Health, NHLI, Imperial College London, UK.
authors.forename: Sukhjinder
authors.initials: S
authors.lastname: Nijjer
authors.affiliation: International Centre for Circulatory Health, NHLI, Imperial College London, UK.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Petraco
authors.affiliation: Biomedical Research Unit, Royal Brompton & Harefield NHS Trust, London, UK.
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Mario
authors.affiliation: International Centre for Circulatory Health, NHLI, Imperial College London, UK.
authors.forename: Justin
authors.initials: J
authors.lastname: Davies
authors.affiliation: National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore.
authors.forename: Philip
authors.initials: P
authors.lastname: Wong
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000295:instrumentation* / Q000379:methods; D023921:Coronary Stenosis / Q000601:surgery*; D054855:Drug-Eluting Stents / Q000009:adverse effects / Q000145:classification; D004868:Equipment Failure; D006801:Humans; D008422:Materials Testing / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D011474:Prosthesis Design / Q000009:adverse effects / Q000379:methods
keywords: DES; Expansion; Left main; Stent