title: Virtual-versus-Real Implantation of Flow Diverters: Clinical Potential and Influence of Vascular Geometry.
abstract: OBJECTIVE
  Intracranial stents have become extremely important in the endovascular management of complex intracranial aneurysms. Sizing and landing zone predictions are still very challenging steps in the procedure. Virtual stent deployment may help therapeutic planning, device choice, and hemodynamic simulations. We aimed to assess the predictability of our recently developed virtual deployment model by comparing in vivo and virtual stents implanted in a consecutive series of patients presenting with intracranial aneurysms.
  
  
  METHODS
  Virtual stents were implanted in patient-specific geometries of intracranial aneurysms treated with the Pipeline Embolization Device. The length and cross-section of virtual and real stents measured with conebeam CT were compared. The influence of vessel geometry modifications occurring during the intervention was analyzed.
  
  
  RESULTS
  The virtual deployment based on pre- and poststent implantation 3D rotational angiography overestimated (underestimated) the device length by 13% ± 11% (-9% ± 5%). These differences were highly correlated (R2= 0.67) with the virtual-versus-real stent radius differences of -6% ± 7% (5% ± 4%) for predictions based on pre- and poststent implantation 3D rotational angiography. These mismatches were due principally to implantation concerns and vessel-shape modifications.
  
  
  CONCLUSIONS
  The recently proposed geometric model was shown to predict accurately the deployment of Pipeline Embolization Devices when the stent radius was well-assessed. However, unpredictable delivery manipulations and variations of vessel geometry occurring during the intervention might impact the stent implantation.
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.|Laboratory for Hydraulic Machines (P.B., M.F.), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: P
authors.identifier: http://orcid.org/0000-0002-4964-8022
authors.initials: P
authors.lastname: Bouillot
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: O
authors.identifier: http://orcid.org/0000-0003-1712-0124
authors.initials: O
authors.lastname: Brina
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: H
authors.identifier: http://orcid.org/0000-0003-4678-5045
authors.initials: H
authors.lastname: Yilmaz
authors.affiliation: Laboratory for Hydraulic Machines (P.B., M.F.), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-4782-2170
authors.initials: M
authors.lastname: Farhat
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: G
authors.identifier: http://orcid.org/0000-0003-0193-3585
authors.initials: G
authors.lastname: Erceg
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: K-O
authors.identifier: http://orcid.org/0000-0003-2768-9779
authors.initials: KO
authors.lastname: Lovblad
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: M I
authors.identifier: http://orcid.org/0000-0002-6571-5336
authors.initials: MI
authors.lastname: Vargas
authors.affiliation: From the Division of Neuroradiology (P.B., O.B., H.Y., G.E., K.-O.L., M.I.V., Z.K.), University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Z
authors.identifier: http://orcid.org/0000-0002-6805-5150
authors.initials: Z
authors.lastname: Kulcsar
authors.affiliation: Division of Neuroradiology (V.M.P.), Department of Medical Imaging vitormpbr@hotmail.com.|Division of Neurosurgery (V.M.P.), Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: V M
authors.identifier: http://orcid.org/0000-0002-6804-3985
authors.initials: VM
authors.lastname: Pereira