title: Hemodynamic analysis of fast and slow aneurysm occlusions by flow diversion in rabbits.
abstract: OBJECTIVE
  To assess hemodynamic differences between aneurysms that occlude rapidly and those occluding in delayed fashion after flow diversion in rabbits.
  
  
  METHODS
  Thirty-six elastase-induced aneurysms in rabbits were treated with flow diverting devices. Aneurysm occlusion was assessed angiographically immediately before they were sacrificed at 1 (n=6), 2 (n=4), 4 (n=8) or 8 weeks (n=18) after treatment. The aneurysms were classified into a fast occlusion group if they were completely or near completely occluded at 4 weeks or earlier and a slow occlusion group if they remained incompletely occluded at 8 weeks. The immediate post-treatment flow conditions in aneurysms of each group were quantified using subject-specific computational fluid dynamics and statistically compared.
  
  
  RESULTS
  Nine aneurysms were classified into the fast occlusion group and six into the slow occlusion group. Aneurysms in the fast occlusion group were on average significantly smaller (fast=0.9 cm, slow=1.393 cm, p=0.024) and had smaller ostia (fast=0.144 cm2, slow=0.365 cm2, p=0.015) than aneurysms in the slow occlusion group. They also had a lower mean post-treatment inflow rate (fast=0.047 mL/s, slow=0.155 mL/s, p=0.0239), kinetic energy (fast=0.519 erg, slow=1.283 erg, p=0.0468), and velocity (fast=0.221 cm/s, slow=0.506 cm/s, p=0.0582). However, the differences in the latter two variables were only marginally significant.
  
  
  CONCLUSIONS
  Hemodynamic conditions after flow diversion treatment of cerebral aneurysms in rabbits are associated with the subsequent aneurysm occlusion time. Specifically, smaller inflow rate, kinetic energy, and velocity seem to promote faster occlusions, especially in smaller and small-necked aneurysms. These results are consistent with previous studies based on clinical series.
authors.affiliation: Department of Bioengineering, Volgenau School of Engineering, George Mason University, 4400 University Drive, MSN 2A1, Fairfax, VA 22030, USA.
authors.forename: Bongjae
authors.initials: B
authors.lastname: Chung
authors.affiliation: Department of Bioengineering, Volgenau School of Engineering, George Mason University, 4400 University Drive, MSN 2A1, Fairfax, VA 22030, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Mut
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Kadirvel
authors.affiliation: Department of Health Sciences and Research, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Ravi
authors.initials: R
authors.lastname: Lingineni
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Kallmes
authors.affiliation: Department of Bioengineering, Volgenau School of Engineering, George Mason University, 4400 University Drive, MSN 2A1, Fairfax, VA 22030, USA.
authors.forename: Juan R
authors.initials: JR
authors.lastname: Cebral
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D001807:Blood Vessel Prosthesis; D006439:Hemodynamics / Q000502:physiology*; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D011817:Rabbits; D011859:Radiography; D015607:Stents
keywords: Aneurysm; Blood Flow; Flow Diverter