title: How do coil configuration and packing density influence intra-aneurysmal hemodynamics?
abstract: OBJECTIVE
  Endovascular coiling is a well-established therapy for treating intracranial aneurysms. Nonetheless, postoperative hemodynamic changes induced by this therapy remain not fully understood. The purpose of this work is to assess the influence of coil configuration and packing density on intra-aneurysmal hemodynamics.
  
  
  METHODS
  Three 3D rotational angiography images of 3 intracranial aneurysms before and after endovascular coiling were used. For each aneurysm, a 3D representation of the vasculature was obtained after the segmentation of the images. Afterward, a virtual coiling technique was used to treat the aneurysm geometries with coil models. The aneurysms were coiled with 5 packing densities, and each was generated by using 3 coil configurations. Computational fluid dynamics analyses were carried out in both untreated and treated aneurysm geometries. Statistical tests were performed to evaluate the relative effect of coil configuration on local hemodynamics.
  
  
  RESULTS
  The intra-aneurysmal blood flow velocity and wall shear stress were diminished as packing density increased. Aneurysmal flow velocity was reduced >50% due to the first inserted coils (packing density <12%) but with a high dependency on coil configuration. Nonsignificant differences (P > .01) were found in the hemodynamics due to coil configuration for high packing densities (near 30%). A damping effect was observed on the intra-aneurysmal blood flow waveform after coiling.
  
  
  CONCLUSIONS
  Intra-aneurysmal hemodynamics are altered by coils. Coil configuration might reduce its influence on intra-aneurysmal hemodynamics as the packing density increases until an insignificant influence could be achieved for high packing densities.
authors: Center for Computational Imaging & Simulation Technologies in Biomedicine, Information & Communication Technologies Department, Universitat Pompeu Fabra, Barcelona, Spain. frangi@upf.edu
authors: H G
authors: HG
authors: Morales
authors: M
authors: M
authors: Kim
authors: E E
authors: EE
authors: Vivas
authors: M-C
authors: MC
authors: Villa-Uriol
authors: I
authors: I
authors: Larrabide
authors: T
authors: T
authors: Sola
authors: L
authors: L
authors: Guimaraens
authors: A F
authors: AF
authors: Frangi
mesh_terms: D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D002548:Cerebral Revascularization / Q000295:instrumentation*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D019544:Equipment Failure Analysis; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D011859:Radiography; D015607:Stents; D016896:Treatment Outcome