title: In Vitro Evaluation of Intra-Aneurysmal, Flow-Diverter-Induced Thrombus Formation: A Feasibility Study.
abstract: OBJECTIVE
  Intracranial aneurysm treatment by flow diverters aims at triggering intra-aneurysmal thrombosis. By combining in vitro blood experiments with particle imaging velocimetry measurements, we investigated the time-resolved thrombus formation triggered by flow diverters.
  
  
  METHODS
  Two test setups were built, 1 for particle imaging velocimetry and 1 for blood experiments, both generating the same pulsatile flow and including a silicone aneurysm model. Tests without flow diverters and with 2 different flow-diverter sizes (diameter: 4.5 and 4.0 mm) were performed. In the blood experiments, the intra-aneurysmal flow was monitored by using Doppler sonography. The experiments were stopped at 3 different changes of the spatial extent of the signal.
  
  
  RESULTS
  No thrombus was detected in the aneurysm model without the flow diverter. Otherwise, thrombi were observed in all aneurysm models with flow diverters. The thrombi grew from the proximal side of the aneurysm neck with fibrin threads connected to the flow diverter and extending across the aneurysm. The thrombus resulting from the 4.0-mm flow diverter grew along the aneurysm wall as a solid and organized thrombus, which correlates with the slower velocities near the wall detected by particle imaging velocimetry. The thrombus that evolved by using the 4.5-mm flow diverter showed no identifiable growing direction. The entire thrombus presumably resulted from stagnation of blood and correlates with the central vortex detected by particle imaging velocimetry.
  
  
  CONCLUSIONS
  We showed the feasibility of in vitro investigation of time-resolved thrombus formation in the presence of flow diverters.
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany kathrin.gester@rwth-aachen.de.
authors.forename: K
authors.initials: K
authors.lastname: Gester
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Lüchtefeld
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Büsen
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany.
authors.forename: S J
authors.initials: SJ
authors.lastname: Sonntag
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Linde
authors.affiliation: From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Steinseifer
authors.affiliation: Acandis GmbH & Co KG (G.C.), Pforzheim, Germany.
authors.forename: G
authors.identifier: http://orcid.org/0000-0003-0550-7049
authors.initials: G
authors.lastname: Cattaneo
mesh_terms: D004621:Embolization, Therapeutic / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D066298:In Vitro Techniques; D002532:Intracranial Aneurysm / Q000628:therapy*; D012212:Rheology; D012984:Software; D015607:Stents; D013927:Thrombosis