title: Histological analysis of extracranial carotid artery aneurysms.
abstract: BACKGROUND
  Extracranial carotid artery aneurysms (ECAA) are rare but may be accompanied with significant morbidity. Previous studies mostly focused on diagnostic imaging and treatment. In contrast, the pathophysiological mechanisms and natural course of ECAA are largely unknown. Understanding the pathophysiological background may add to prediction of risk for adverse outcome and need for surgical exclusion. The aim of this study was to investigate the histopathological characteristics of ECAA in patients who underwent complete surgical ECAA resection.
  
  
  METHODS
  From March 2004 till June 2013, 13 patients were treated with open ECAA repair. During surgery the aneurysm sac was resected and processed for standardized histological analysis. Sections were stained with routine hematoxylin and eosin and special stains to detect elastin, collagen, different types of inflammatory cells, vascular smooth muscle cells and endothelial cells.
  
  
  RESULTS
  Histopathological characterization revealed two distinct categories: dissection (abrupt interruption of the media; n = 3) and degeneration (general loss of elastin fibers in the media; n = 10). In the degenerative samples the elastin fibers in the media were fragmented and were partly absent. Inflammatory cells were observed in the vessel wall of the aneurysms.
  
  
  CONCLUSIONS
  Histological analysis in this small sample size revealed dissection and degeneration as the two distinct underlying mechanisms in ECAA formation.
authors: Vascular Surgery, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Janna C
authors: JC
authors: Welleweerd
authors: Vascular Surgery, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands; Experimental Cardiology laboratory, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Bastiaan G L
authors: BG
authors: Nelissen
authors: Vascular Surgery, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands; Experimental Cardiology laboratory, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Dave
authors: D
authors: Koole
authors: Vascular Surgery, St Antonius Hospital, Koekoekslaan 1, 3435CM Nieuwegein, the Netherlands.
authors: Jean-Paul P M
authors: JP
authors: de Vries
authors: Vascular Surgery, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Frans L
authors: FL
authors: Moll
authors: Experimental Cardiology laboratory, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Gerard
authors: G
authors: Pasterkamp
authors: Pathology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Aryan
authors: A
authors: Vink
authors: Vascular Surgery, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands.
authors: Gert Jan
authors: GJ
authors: de Borst
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000473:pathology*; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
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