title: Hemodynamics of 8 different configurations of stenting for bifurcation aneurysms.
abstract: OBJECTIVE
  SACE is performed for complex aneurysms. There are several configurations of stent placement for bifurcation aneurysms. We investigated hemodynamics among 8 different configurations of stent placement, which may relate to the recanalization rate.
  
  
  METHODS
  We created a silicone block model of a patient-specific asymmetric bifurcation aneurysm. Enterprise closed-cell stents were deployed in the model as various configurations. 3D images of these stents were obtained by micro-CT. We performed CFD simulations for a no-stent model and 8 stent models: a single stent from a proximal vessel to a right or left distal vessel, a horizontal stent, a kissing-Y stent with a uniformly narrowed structure, a nonoverlapping-Y stent, a virtual-Y stent with no narrowed structure (fusion of 2 single stents), and 2 different crossing-Y stents with a focally narrowed structure. Hemodynamic parameters were evaluated.
  
  
  RESULTS
  Cycle-averaged velocity and WSS in the aneurysm were reduced because of stent placement in the following order: single stent (19% reduction in cycle-averaged velocity) < nonoverlapping-Y stent (29%) < virtual-Y stent (32%) < horizontal stent (39%) < kissing-Y stent (48%) < crossing-Y stent (54%). Kissing- and crossing-Y stents redirected impingement flow into the distal vessels because of lowered porosity of stents due to narrowed structures.
  
  
  CONCLUSIONS
  Among 8 different configurations of stent placement, kissing- and crossing-Y stents showed the strongest reduction in flow velocity in the aneurysm because of lowered porosity of stents and redirection of impingement flow. This may be a desirable reconstruction of flow hemodynamics and may decrease recanalization rates in SACE.
authors.affiliation: Department of Neurosurgery, Wakayama Rosai Hospital, Wakayama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kono
authors.forename: T
authors.initials: T
authors.lastname: Terada
mesh_terms: D017130:Angioplasty / Q000379:methods*; D003198:Computer Simulation; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D012828:Silicones; D015607:Stents; D013314:Stress, Mechanical; D055114:X-Ray Microtomography
chemical_list: D012828:Silicones