title: Carotid plaque fissure: An underestimated source of intraplaque hemorrhage.
abstract: Plaque fissuring, a phenomenon morphologically distinct from the classical rupture of a thinned fibrous cap, has not been well characterized in carotid atherosclerosis. The aim of this study was to establish the prevalence of plaque fissures in advanced carotid plaques with an otherwise intact luminal surface, and to determine whether they might be a source of intraplaque hemorrhage (IPH).
  
  
  
  We evaluated 244 surgically intact, 'en bloc' embedded, serially sectioned carotid endarterectomy specimens and included only those plaques with a grossly intact luminal surface.
  
  
  
  Among the 67 plaques with grossly intact luminal surface, cap fissure was present in 39 (58%) plaques. A total of 60 individual fissures were present, and longitudinally mean fissure length was 1.3 mm. Most fissures were found distal to the bifurcation (63%), proximal to the stenosis (88%), and in the posterior (opposite the flow divider) or lateral quadrants (80%). 36% of the fissures remained in the superficial third of the plaque. 52% extended from the lumen surface to the middle third of the plaque and 12% reached the outer third of the plaque on cross section. Fissures often occurred between two tissue planes and were connected to IPH (fresh: 63%; any type: 92%) and calcifications (43%). No correlation was found with patient characteristics such as symptom status, carotid stenosis, hypertension, diabetes, smoking and medications (statins or antiplatelet agents).
  
  
  
  Plaque fissures are common in advanced carotid plaques with an otherwise grossly intact luminal surface and are associated with fresh intraplaque hemorrhage. As they occur on the interface between plaque components with different mechanical properties, further biomechanical studies are needed to unravel the underlying failure mechanisms.
authors.affiliation: Department of Pathology, Academic Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands. Electronic address: m.j.daemen@amc.uva.nl.
authors.forename: Mat J
authors.initials: MJ
authors.lastname: Daemen
authors.affiliation: Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Ferguson
authors.affiliation: Biochemical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gijsen
authors.affiliation: Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Hippe
authors.affiliation: Department of Radiology, Maastricht University Medical Center, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.
authors.forename: M Eline
authors.initials: ME
authors.lastname: Kooi
authors.affiliation: Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Department of Radiology, Building 9, Room 1799, Bethesda, MD 20889, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Demarco
authors.affiliation: Department of Pathology, Academic Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Allard C
authors.initials: AC
authors.lastname: van der Wal
authors.affiliation: Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA.
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of Surgery, Division of Vascular Surgery, University of Washington, Vascular Imaging Laboratory, 850 Republican Street, Brotman Building Room 124, Seattle, WA 98019, USA.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002339:Carotid Arteries / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000503:physiopathology; D016894:Endarterectomy, Carotid; D005260:Female; D006470:Hemorrhage / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D058226:Plaque, Atherosclerotic / Q000503:physiopathology*; D015995:Prevalence
keywords: Atherosclerosis; Hemorrhage; Plaque