title: Flow diverter effect on cerebral aneurysm hemodynamics: an in vitro comparison of telescoping stents and the Pipeline.
abstract: BACKGROUND
  Flow diverting devices and stents can be used to treat cerebral aneurysms too difficult to treat with coiling or craniotomy and clipping. However, the hemodynamic effects of these devices have not been studied in depth. The objective of this study was to quantify and understand the fluid dynamic changes that occur within bifurcating aneurysms when treated with different devices and configurations.
  
  
  METHODS
  Two physical models of bifurcating cerebral aneurysms were constructed: an idealized model and a patient-specific model. The models were treated with four device configurations: a single low-porosity Pipeline embolization device (PED) and one, two, and three high-porosity Enterprise stents deployed in a telescoping fashion. Particle image velocimetry was used to measure the fluid dynamics within the aneurysms; pressure was measured within the patient-specific model.
  
  
  RESULTS
  The PED resulted in the greatest reductions in fluid dynamic activity within the aneurysm for both models. However, a configuration of three telescoping stents reduced the fluid dynamic activity within the aneurysm similarly to the PED treatment. Pressure within the patient-specific aneurysm did not show significant changes among the treatment configurations; however, the pressure difference across the untreated vessel side of the model was greatest with the PED.
  
  
  CONCLUSIONS
  Treatment with stents and a flow diverter led to reductions in aneurysmal fluid dynamic activity for both idealized and patient-specific models. While the PED resulted in the greatest flow reductions, telescoping high-porosity stents performed similarly and may represent a viable treatment alternative in situations where the use of a PED is not an option.
authors.affiliation: School of Biological and Health Systems Engineering, Arizona State University, P.O. Box 879709, Tempe, AZ 85287-9709, USA. broszelle@gmail.com
authors.forename: Breigh N
authors.initials: BN
authors.lastname: Roszelle
authors.forename: L Fernando
authors.initials: LF
authors.lastname: Gonzalez
authors.forename: M Haithem
authors.initials: MH
authors.lastname: Babiker
authors.forename: Justin
authors.initials: J
authors.lastname: Ryan
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Albuquerque
authors.forename: David H
authors.initials: DH
authors.lastname: Frakes
mesh_terms: D032701:Biomimetics / Q000295:instrumentation; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D002560:Cerebrovascular Circulation; D019544:Equipment Failure Analysis; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000601:surgery*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D015607:Stents; D016896:Treatment Outcome