title: The pressure reduction coefficient: A new parameter to assess aneurysmal blood stasis induced by flow diverters/disruptors.
abstract: Background and purpose Pore density (PD), surface metal coverage (SMC) and the number of wires are all different parameters which can influence the efficacy of a flow disruptor/diverter. Nevertheless, the relative importance of a parameter to induce intra-aneurysmal blood stasis is still poorly evaluated. Therefore, comparison between devices based on a unique value is not reliable. The aim of this study was to propose a new bench top parameter (the pressure reduction coefficient (PRC; ξ)) in order to assess the global haemodynamic effect of each flow diverter/disruptor to slow flow. Methods Eight devices were tested in vitro during three different flow conditions. For the eight devices, the PRC was computed at different volumetric flow rates to characterise flow reduction. Comparison was made with SMC, PD and the number of wires. Results The PRC obtained for flow disruptors was on average 1.5 times more efficient in reducing flow compared to flow diverters. PD (mm2) ranged from 24 to 38 for flow diverters and did not independently correlate with the PRC. The SMC of flow diverters ranged from 25% to 70%, and ranged from 20% to 100% for flow disruptors, without independent correlation to the PRC. The number of wires ranged from 48 to 96 for the flow diverters and did not correlate independently to the PRC. Conclusion There were no direct correlations between individual device characteristics and the PRC, suggesting a multifaceted and interrelating association of the overall design of each implant. Hence, the PRC could be used as a simple, reliable parameter to assess the overall capacity of flow disruptors/diverters to induce intra-aneurysmal blood stasis.
authors.affiliation: 1 Department of Neuroradiology, CHU Gui de Chauliac, Montpellier, France.
authors.forename: Gregory
authors.initials: G
authors.lastname: Gascou
authors.affiliation: 2 Laboratoire de mécanique et de génie civil, Universite de Montpellier, Montpellier, France.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ferrara
authors.affiliation: 2 Laboratoire de mécanique et de génie civil, Universite de Montpellier, Montpellier, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Ambard
authors.affiliation: 2 Laboratoire de mécanique et de génie civil, Universite de Montpellier, Montpellier, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Sanchez
authors.affiliation: 3 Charing Cross Hospital, Imperial College Hospitals, NHS Trust, London, UK.
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Lobotesis
authors.affiliation: 2 Laboratoire de mécanique et de génie civil, Universite de Montpellier, Montpellier, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Jourdan
authors.affiliation: 1 Department of Neuroradiology, CHU Gui de Chauliac, Montpellier, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Costalat
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D001807:Blood Vessel Prosthesis; D003198:Computer Simulation; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D066298:In Vitro Techniques; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000628:therapy*; D008955:Models, Cardiovascular
keywords: Flow disruptor; flow diverter; haemodynamic; pore density; surface metal coverage