title: Computational analysis of hemodynamics using a two-dimensional model in moyamoya disease.
abstract: OBJECTIVE
  Bilateral intimal thickening of the distal internal carotid arteries (ICAs) and the development of many collateral vessels in the base of the brain characterize moyamoya disease (MMD). Although the etiology of and the reason why MMD is limited to the major intracranial vessels remain unclear, flow dynamics, such as shear stress, may be related to its smooth-muscle cell migration. Therefore, this study was performed to determine the local hemodynamic factor, which concerns the predominance of specific anatomical sites, such as the distal ICA in the early stage and the proximal posterior cerebral artery (PCA) in the advanced stage of MMD.
  
  
  METHODS
  The authors simulated the hemodynamics in the circle of Willis using computational models of 2D geometries of the distal ICA and PCA. A finite-element commercial package, automatic dynamics incremental nonlinear analysis (ADINA), was used to simulate blood flow in these arteries.
  
  
  RESULTS
  Numerical results demonstrated that shear stress was relatively low at the ICA region. The distribution of shear stress was related to the predisposing area of MMD.
  
  
  CONCLUSIONS
  Diminished shear stress may promote stenosis of the distal ICA, which is a major pathological region in MMD.
authors.affiliation: Department of Neurosurgery, Kangwon National University, Chuncheon, South Korea.
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Seol
authors.forename: Duk Chul
authors.initials: DC
authors.lastname: Shin
authors.forename: Yoo Seok
authors.initials: YS
authors.lastname: Kim
authors.forename: Eun Bo
authors.initials: EB
authors.lastname: Shim
authors.forename: Seung-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Byung-Kyu
authors.initials: BK
authors.lastname: Cho
authors.forename: Kyu-Chang
authors.initials: KC
authors.lastname: Wang
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D002343:Carotid Artery, Internal / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology; D006801:Humans; D008955:Models, Cardiovascular; D009072:Moyamoya Disease / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology; D033081:Shear Strength; D014655:Vascular Resistance / Q000502:physiology