title: Vascular geometry of the extracranial carotid arteries: an analysis of length, diameter, and tortuosity.
abstract: BACKGROUND
  Stable access is essential for successful intracranial interventions. Quantifying variations in extracranial carotid arteries may help in the selection and development of access catheters. This study describes the vascular dimensions from the aortic arch to the skull base.
  
  
  METHODS
  CT angiography analysis was performed on 100 patients. The lengths, diameters, and tortuosity of the common carotid artery (CCA) and internal carotid artery (ICA) were measured from the aortic arch to the skull base.
  
  
  RESULTS
  The mean±SD length of the carotid artery from the aortic arch to the skull base was 22.2±2.2 cm for the right side and 20.8±1.9 cm for the left side (p<0.0001). The length of the right CCA was 13.6±1.2 cm and the length of the left CCA was 12.4±1.4 cm (p<0.0001). The length of the right ICA was 8.6±1.4 cm compared with 8.4±1.4 cm for the left ICA (p=0.3). The ICA length in men and women was 8.9±1.3 cm and 8.2±1.3 cm, respectively (p=0.0001), and the CCA length in men and women was 13.6±1.5 cm and 12.3±1.6 cm, respectively (p<0.0001). The lengths of the CCA and ICA in patients aged ≥60 years were 13.3±1.7 cm and 8.9±1.5 cm, respectively compared with 12.8±1.7 cm and 8.2±1.1 cm, respectively, for patients aged <60 years (p=0.04 for CCA, p=0.0002 for ICA). Tortuosity of the CCA and ICA was 1.2±0.2 and 1.3±0.1, respectively, in patients aged ≥60 years compared with 1.1±0.1 for both the ICA and CCA in patients aged <60 years (p<0.0001 for both). There was a consistent ratio of CCA/ICA length of 1.6±0.3 on the right and 1.5±0.3 on the left (p<0.0001). The arterial diameters did not show any significant difference.
  
  
  CONCLUSIONS
  The distance from the aortic arch to the skull base is longer on the right than on the left side. Both the CCA and ICA are longer in men and in patients aged ≥60 years. The tortuosity of both segments significantly increases with age.
authors.affiliation: Department of Radiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Farooq A
authors.initials: FA
authors.lastname: Choudhry
authors.affiliation: Department of Radiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Grantham
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Ansaar T
authors.initials: AT
authors.lastname: Rai
authors.affiliation: Department of Radiology, West Virginia University Healthcare, Morgantown, West Virginia, USA.
authors.forename: Jeffery P
authors.initials: JP
authors.lastname: Hogg
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic / Q000033:anatomy & histology* / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D017536:Carotid Artery, Common / Q000033:anatomy & histology* / Q000502:physiology; D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000502:physiology; D000072226:Computed Tomography Angiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019291:Skull Base / Q000033:anatomy & histology / Q000098:blood supply
keywords: Angiography; Artery; CT Angiography; Device; Statistics