title: Numerical analysis of hemodynamics in spastic middle cerebral arteries.
abstract: Cerebral vasospasm (CVS) is the most common serious complication of subarachnoid hemorrhage. Among the many factors that are associated with the pathogenesis of CVS, hemodynamics plays an important role in the initiation and development of CVS. Numerical simulation was carried out to obtain the flow patterns and wall shear stress (WSS) distribution in spastic middle cerebral arteries. The blood was assumed to be incompressible, laminar, homogenous, Newtonian, and steady. Our simulations reveal that flow velocity and WSS level increase at the stenosis segment of the spastic vessels, but further downstream of stenosis, the WSS significantly decreases along the inner wall, and flow circulation and stagnation are observed. The hydrodynamic resistance increases with the increase of vessel spasm. Moreover, the change of flow field and hydrodynamic forces are not linearly proportional to the spasm level, and the rapid change of hemodynamic parameters is observed as the spasm is more than 50%. Accordingly, in the view of hemodynamic physiology, vessels with less than 30% stenosis are capable of self-restoration towards normal conditions. However, vessels with more than 50% stenosis may eventually lose their capacity to adapt to differing physiologic conditions due to the extreme non-physilogic hemodynamic environment, and the immediate expansion of the vessel lumen might be needed to minimize serious and non-reversible effects.
authors.affiliation: a School of Civil Engineering and Architecture , Southwest University of Science and Technology , Mianyang , China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wen
authors.affiliation: b West China School of Medicine, Sichuan University , Chengdu , China.
authors.forename: Qingfeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: c Department of Applied Mechanics , Sichuan University , Chengdu , China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Wang
authors.affiliation: d School of Electrical and Computer Engineering , RMIT University , Melbourne , Australia.
authors.forename: Khashayar
authors.initials: K
authors.lastname: Khoshmanesh
authors.affiliation: c Department of Applied Mechanics , Sichuan University , Chengdu , China.
authors.forename: Tinghui
authors.initials: T
authors.lastname: Zheng
mesh_terms: D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D020768:Middle Cerebral Artery / Q000503:physiopathology*; D008954:Models, Biological; D009128:Muscle Spasticity / Q000503:physiopathology*; D009716:Numerical Analysis, Computer-Assisted; D013314:Stress, Mechanical
keywords: Middle cerebral artery (MCA); hemodynamics; numerical simulation; subarachnoid hemorrhage(SAH); vasospasm