title: Combined Effects of Flow Diverting Strategies and Parent Artery Curvature on Aneurysmal Hemodynamics: A CFD Study.
abstract: OBJECTIVE
  Flow diverters (FD) are increasingly being considered for treating large or giant wide-neck aneurysms. Clinical outcome is highly variable and depends on the type of aneurysm, the flow diverting device and treatment strategies. The objective of this study was to analyze the effect of different flow diverting strategies together with parent artery curvature variations on altering intra-aneurysmal hemodynamics.
  
  
  METHODS
  Four ideal intracranial aneurysm models with different parent artery curvature were constructed. Computational fluid dynamics (CFD) simulations of the hemodynamics before and after applying five types of flow diverting strategies (single FD, single FD with 5% and 10% packing density of coils, two FDs with 25% and 50% overlapping rate) were performed. Changes in pressure, wall shear stress (WSS), relative residence time (RRT), inflow velocity and inflow volume rate were calculated and compared.
  
  
  RESULTS
  Each flow diverting strategy resulted in enhancement of RRT and reduction of normalized mean WSS, inflow volume rate and inflow velocity in various levels. Among them, 50% overlapped FD induced most effective hemodynamic changes in RRT and inflow volume rate. The mean pressure only slightly decreased after treatment. Regardless of the kind of implantation of FD, the mean pressure, inflow volume rate and inflow velocity increased and the RRT decreased as the curvature of the parent artery increased.
  
  
  CONCLUSIONS
  Of all flow diverting strategies, overlapping FDs induced most favorable hemodynamic changes. Hemodynamics alterations post treatment were substantially influenced by parent artery curvature. Our results indicate the need of an individualized flow diverting strategy that is tailored for a specific aneurysm.
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Jinyu
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of International Relations and Public Affairs, Fudan University, Shanghai, China.
authors.forename: Zhichen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Lv
authors.affiliation: Department of Mechanics and Engineering Science, Fudan University, Shanghai, China.
authors.forename: Shengzhang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Cerebrovascular Center, Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, United States of America.
authors.forename: Christof
authors.initials: C
authors.lastname: Karmonik
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Huang
mesh_terms: D001158:Arteries / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003198:Computer Simulation; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D057446:Hydrodynamics; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000628:therapy*; D008955:Models, Cardiovascular