title: Endothelialization of over- and undersized flow-diverter stents at covered vessel side branches: An in vivo and in silico study.
abstract: Although flow-diverting devices are promising treatment options for intracranial aneurysms, jailed side branches might occlude leading to insufficient blood supply. Especially differences in the local stent strut compression may have a drastic influence on subsequent endothelialization. To investigate the outcome of different treatment scenarios, over- and undersized stent deployments were realized experimentally and computationally. Two Pipeline Embolization Devices were placed in the right common carotid artery of large white swine, crossing the right ascending pharyngeal artery. DSA and PC-MRI measurements were acquired pre- and post-stenting and after three months. To evaluate the stent strut endothelialization and the corresponding ostium patency, the swine were sacrificed and scanning electron microscopy measurements were carried out. A more detailed analysis of the near-stent hemodynamics was enabled by a realistic virtual stenting in combination with highly resolved Computational Fluid Dynamics simulations using case-specific boundary conditions. The oversizing resulted in an elongated stent deployment with more open stent pores, while for the undersized case a shorter deployment with more condensed pores was present. In consequence, the side branch of the first case remained patent after three months and the latter almost fully occluded. The virtual investigation confirmed the experimental findings by identifying differences between the individual velocities as well as stent shear stresses at the distal part of the ostia. The choice of flow-diverting device and the subsequent deployment strategy strongly influences the patency of jailed side branches. Therefore, careful treatment planning is required, to guarantee sufficient blood supply in the brain territories supplied those branches.
authors.affiliation: Department of Fluid Dynamics and Technical Flow, University of Magdeburg "Otto-von-Guericke", D-39106 Magdeburg, Germany. Electronic address: berg@ovgu.de.
authors.forename: Philipp
authors.initials: P
authors.lastname: Berg
authors.affiliation: Interventional Neuroradiology Department, Dupuytren University Hospital (CHU Limoges), F-87000 Limoges, France; Applied Medical Research Team (ERMA), University of Limoges, F-87000 Limoges, France.
authors.forename: Christina
authors.initials: C
authors.lastname: Iosif
authors.affiliation: Anesthesiology Department, Dupuytren University Hospital (CHU Limoges), F-87000 Limoges, France.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Ponsonnard
authors.affiliation: Applied Medical Research Team (ERMA), University of Limoges, F-87000 Limoges, France; Department of Histology, Cytology, Cellular Biology and Cytogenetics, Mother and Child (HME) University Hospital, F-87000 Limoges, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Yardin
authors.affiliation: Department of Fluid Dynamics and Technical Flow, University of Magdeburg "Otto-von-Guericke", D-39106 Magdeburg, Germany.
authors.forename: Gábor
authors.initials: G
authors.lastname: Janiga
authors.affiliation: Interventional Neuroradiology Department, Dupuytren University Hospital (CHU Limoges), F-87000 Limoges, France; Applied Medical Research Team (ERMA), University of Limoges, F-87000 Limoges, France.
authors.forename: Charbel
authors.initials: C
authors.lastname: Mounayer
mesh_terms: D000792:Angiography; D000818:Animals; D017536:Carotid Artery, Common; D003198:Computer Simulation; D004727:Endothelium / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics; D057446:Hydrodynamics; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008855:Microscopy, Electron, Scanning; D012984:Software; D015607:Stents; D013552:Swine
keywords: Computational Fluid Dynamics (CFD); Endothelialization; Flow-diverting stent; Stent shear stress; Virtual stenting