title: Characterisation of a novel porcine coronary artery CTO model.
abstract: OBJECTIVE
  To create a large animal coronary chronic total occlusion (CTO) model. Presence of microvessels within the CTO lumen facilitates guidewire crossing. The patterns and time profiles of matrix changes and microvessel formation during coronary CTO maturation are unknown.
  
  
  RESULTS
  CTO were created in 15 swine by percutaneous deployment of a collagen plug. Matrix changes were assessed by histology. Intraluminal neovascularisation was assessed by histology and several imaging modalities, including conventional and 3D spin angiography, micro-computed tomography (micro-CT) imaging, and contrast-enhanced magnetic resonance imaging (MRI), at six and 12 weeks following CTO creation. Matrix changes included an intense inflammatory reaction at six weeks which had partially abated by 12 weeks. A proteoglycan-rich matrix at six weeks was partially replaced with collagen by 12 weeks. Similar changes were noted in the proximal cap which was acellular. Three patterns of microvessel formation were identified and defined based on the presence and extent of a "lead" neovessel. No major differences in pattern or extent of neovascularisation were noted between six and 12 weeks.
  
  
  CONCLUSIONS
  Heterogeneity in neovascularisation patterns occurs during coronary CTO development in a porcine model. Non-invasive imaging to determine the predominant type of neovascularisation prior to and during CTO revascularisation may improve guidewire crossing success rates. This model may be useful for further exploration of CTO pathophysiology, and may aid in further refinements of in vivo imaging of CTO and development of novel therapeutic approaches to revascularisation of CTO, such as manipulations of the proximal cap, matrix composition, neovessel induction, and device testing.
authors.affiliation: Division of Cardiology, Schulich Heart Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Fefer
authors.forename: Normand
authors.initials: N
authors.lastname: Robert
authors.forename: Beiping
authors.initials: B
authors.lastname: Qiang
authors.forename: Garry
authors.initials: G
authors.lastname: Liu
authors.forename: Nigel
authors.initials: N
authors.lastname: Munce
authors.forename: Kevan
authors.initials: K
authors.lastname: Anderson
authors.forename: Azriel B
authors.initials: AB
authors.lastname: Osherov
authors.forename: Michelle
authors.initials: M
authors.lastname: Ladouceur-Wodzak
authors.forename: Xiuling
authors.initials: X
authors.lastname: Qi
authors.forename: Alexander
authors.initials: A
authors.lastname: Dick
authors.forename: Max
authors.initials: M
authors.lastname: Weisbrod
authors.forename: Michelle
authors.initials: M
authors.lastname: Samuel
authors.forename: Jagdish
authors.initials: J
authors.lastname: Butany
authors.forename: Graham
authors.initials: G
authors.lastname: Wright
authors.forename: Bradley H
authors.initials: BH
authors.lastname: Strauss
mesh_terms: D000818:Animals; D002908:Chronic Disease; D054059:Coronary Occlusion / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D004195:Disease Models, Animal; D005260:Female; D008279:Magnetic Resonance Imaging; D013552:Swine; D014057:Tomography, X-Ray Computed