title: Differences in neointimal thickness between the adluminal and the abluminal sides of malapposed and side-branch struts in a polylactide bioresorbable scaffold: evidence in vivo about the abluminal healing process.
abstract: OBJECTIVE
  The goal of this study was to describe the neointimal healing on the abluminal side (ABL) of malapposed (ISA) struts and nonapposed side-branch (NASB) struts in terms of coverage by optical coherence tomography (OCT) and in comparison with the adluminal side (ADL).
  
  
  BACKGROUND
  The neointimal healing on the ABL of ISA and NASB struts has never to our knowledge been explored in vivo and could be involved in the correction of acute malapposition. The bioresorbable vascular scaffold (BVS) is made of a translucent polymer that enables imaging of the ABL with OCT.
  
  
  METHODS
  Patients enrolled in the ABSORB B (ABSORB Clinical Investigation Cohort B) study were treated with implantation of a BVS and imaged with OCT at 6 months. Thickness of coverage on the ADL and ABL of ISA and NASB struts was measured by OCT.
  
  
  RESULTS
  Twenty-eight patients were analyzed; 114 (2.4%) struts were malapposed or at side branches. In 76 ISA struts (89.4%) and 29 NASB struts (100%), the thickness of ABL coverage was >30 μm. Coverage was thicker on the ABL than on the ADL side (101 vs. 71 μm; 95% confidence interval [CI] of the difference: 20 to 40 μm). In 70 struts (60.7%, 95% CI: 50.6% to 70.0%), the neointimal coverage was thicker on the ABL, versus only 20 struts (18.5%, 95% CI: 11.6% to 28.1%) with thicker neointimal coverage on the ADL side (odds ratio: 3.35, 95% CI: 2.22 to 5.07).
  
  
  CONCLUSIONS
  Most of the malapposed and side-branch struts are covered on the ABL side 6 months after BVS implantation, with thicker neointimal coverage than on the ADL side. The physiological correction of acute malapposition involves neointimal growth from the strut to the vessel wall or bidirectional. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856).
authors.affiliation: Interventional Cardiology Department, Erasmus Medical Centre, Thoraxcentre, Rotterdam, The Netherlands.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Gutiérrez-Chico
authors.forename: Frank
authors.initials: F
authors.lastname: Gijsen
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Jolanda
authors.initials: J
authors.lastname: Wentzel
authors.forename: Bernard
authors.initials: B
authors.lastname: de Bruyne
authors.forename: Leif
authors.initials: L
authors.lastname: Thuesen
authors.forename: John
authors.initials: J
authors.lastname: Ormiston
authors.forename: Dougal R
authors.initials: DR
authors.lastname: McClean
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
authors.forename: Bernard
authors.initials: B
authors.lastname: Chevalier
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dudek
authors.forename: Robert
authors.initials: R
authors.lastname: Whitbourn
authors.forename: Salvatore
authors.initials: S
authors.lastname: Brugaletta
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D020341:Absorbable Implants; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D001315:Australia; D002317:Cardiovascular Agents / Q000008:administration & dosage; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible; D003324:Coronary Artery Disease / Q000473:pathology / Q000628:therapy*; D003331:Coronary Vessels / Q000473:pathology*; D005060:Europe; D000068338:Everolimus; D005260:Female; D006801:Humans; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000175:diagnosis / Q000209:etiology / Q000473:pathology*; D009520:New Zealand; D011091:Polyesters; D011108:Polymers; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012042:Registries; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives; D013997:Time Factors; D054457:Tissue Scaffolds; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome
chemical_list: D002317:Cardiovascular Agents; D020099:Coated Materials, Biocompatible; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D000068338:Everolimus; D020123:Sirolimus