title: The effect of anatomic variations of circle of Willis on cerebral blood distribution during posture change from supination to standing: a model study.
abstract: The anatomic variation of Circle of Willis (CoW) has great impact on its compensatory capacity during stroke and cerebral ischemia. In the present study, a series of lumped parameter models were developed and used to simulate the effect of postural changes on the cerebral blood flow in ICA stenosis patients with different anatomic variants of the CoW. The results showed that the asymmetric distribution of cerebral blood flow caused by stenosis was attenuated in standing position in complete and half-complete CoW. However, in incomplete CoW, the decrease in blood flow in the ipsilateral cerebral arteries caused by unilateral ICA stenosis was dramatic in both supine and standing positions, a likely result of inadequate collateral circulation within the CoW. In conclusion, the anatomic variation of CoW plays a significant role in maintaining the balance of cerebral blood supply in patients with ICA stenosis, especially during postural change.
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
authors.forename: Shuyu
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China State Key Lab of Virtual Reality of Technology and Systems, Beihang University, Beijing 100191, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Pu
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China State Key Lab of Virtual Reality of Technology and Systems, Beihang University, Beijing 100191, China.
authors.forename: Yubo
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China State Key Lab of Virtual Reality of Technology and Systems, Beihang University, Beijing 100191, China.
authors.forename: Deyu
authors.initials: D
authors.lastname: Li
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D016893:Carotid Stenosis / Q000150:complications / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000002:abnormalities* / Q000503:physiopathology*; D003198:Computer Simulation; D006801:Humans; D008955:Models, Cardiovascular; D004856:Postural Balance; D011187:Posture; D013484:Supination; D014655:Vascular Resistance
keywords: Circle of Willis; anatomic variation; internal carotid artery stenosis; lumped parameter model; posture change