title: Hemodynamic relationship between intracranial aneurysm and carotid stenosis: review of clinical cases and numerical analyses.
abstract: OBJECTIVE
  Coexistence of both an intracranial aneurysm and a stenosis at the same internal carotid artery is infrequent, but it may complicate therapeutic management of either disease. It is unclear if a stenosis plays any role in development of intracranial aneurysms. We study patients with intracranial aneurysms at our hospital and investigate if there is a relationship between a carotid stenosis and an intracranial aneurysm.
  
  
  METHODS
  Two hundred and nine patients who were treated for their intracranial aneurysms in a 2-year period were reviewed. Fifty-four patients were found to have at least one intracranial aneurysm and one intracranial or extracranial carotid stenosis. Ten of them had bilateral stenoses; 17 aneurysms were on the ipsilateral side of the stenosis, and eight on the contralateral side. Nineteen aneurysms were elsewhere. Two cases were selected for detailed computational fluid dynamics (CFD) analyses: one with an intracranial and the other with an extracranial stenosis.
  
  
  RESULTS
  Aneurysms on the contralateral side of a carotid stenosis are significantly larger than those aneurysms on the ipsilateral side or with bilateral stenoses (13.6 versus 6.6 mm; P < 0.01). CFD studies show that wall shear stress at the aneurysm is more likely affected by an adjacent intracranial stenosis than by an extracranial stenosis.
  
  
  CONCLUSIONS
  Intracranial carotid aneurysms contralateral to a carotid stenosis are significantly larger than aneurysms with a carotid stenosis elsewhere. Rupture can occur on aneurysms with an extracranial carotid stenosis on the contralateral side or with an intracranial carotid stenosis on the ipsilateral side.
authors.affiliation: Department of Radiology, Baylor College of Medicine, Houston, TX 77030, USA. jou@bcm.tmc.edu
authors.forename: Liang-Der
authors.initials: LD
authors.lastname: Jou
authors.forename: Hashem M
authors.initials: HM
authors.lastname: Shaltoni
authors.forename: Hesham
authors.initials: H
authors.lastname: Morsi
authors.forename: Michel E
authors.initials: ME
authors.lastname: Mawad
mesh_terms: D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D015897:Comorbidity / Q000639:trends; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies