Hydrodynamical evaluation of microporous covered stent for the treatment of intracranial aneurysms: Comparison of flow reduction property with flow diverter stent by using particle imaging velocimetry and in vitro flow simulator

Moriwaki, Takeshi; Tajikawa, Tsutomu; Nakayama, Yasuhide

doi:10.17106/jbr.32.20

Cited by 5 publications

(10 citation statements)

References 16 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental setup has already been presented in detail in previous reports [18,19]. A schematic of the flow simulator is shown in Fig.…”

Section: In Vitro Flow Simulatormentioning

confidence: 99%

“…Consequently, the relationship between its pore size and flow-reduction properties was clarified [18]. Moreover, the flow-reduction *E-mail: moriwaki@hirosaki-u.ac.jp properties of NCVC-CS1 were also investigated [19].…”

Section: Introductionmentioning

confidence: 99%

“…In IAs that occur outside the curved vessels, the IA flow intensity is considerably higher than that of those that occur in straight vessels because of the direct inflow and secondary flow effects. Thus, it is necessary to use a stent with high flow-reduction capabilities, such as a flow isolator, for treating IAs exposed to fast flow [19]. It is a remaining task to explain the relationships between AMSR and IA morphology by hemodynamic theory.…”

mentioning

confidence: 99%

See 2 more Smart Citations

In vitro hydrodynamical study on aneurysmal morphology for treating intracranial aneurysms using particle imaging velocimetry

2020

Self Cite

View full text Add to dashboard Cite

“…The experimental setup has already been presented in detail in previous reports [18,19]. A schematic of the flow simulator is shown in Fig.…”

Section: In Vitro Flow Simulatormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

In vitro hydrodynamical study on aneurysmal morphology for treating intracranial aneurysms using particle imaging velocimetry

2020

Self Cite

View full text Add to dashboard Cite

“…2013), stent ‘patterns’ (Lieber et al. 2002; Liou, Liou & Chu 2004; Moriwaki, Tajikawa & Nakayama 2018) and deployment (Babiker et al. 2012; Roloff & Berg 2022) impact intra-aneurysmal haemodynamics.…”

Section: Introductionmentioning

confidence: 99%

“…Finally, other important parameters in post-treatment haemodynamics are the stent porosity and permeability. Numerous experimental studies have investigated different stent designs (Dorn et al 2011), showing that porosity Liou, Li & Wang 2008;Rayepalli et al 2013), stent 'patterns' (Lieber et al 2002;Liou, Liou & Chu 2004;Moriwaki, Tajikawa & Nakayama 2018) and deployment (Babiker et al 2012;Roloff & Berg 2022) impact intra-aneurysmal haemodynamics. Yu et al (2012) repeated PIV measurements for a steady inflow in an aneurysm attached to a straight parent vessel, with four porosity values.…”

Section: Introductionmentioning

confidence: 99%

Fluid dynamics in intracranial aneurysms treated with flow-diverting stents: effect of multiple geometrical parameters

Chassagne,

Barbour,

Levitt

et al. 2023

J. Fluid Mech.

View full text Add to dashboard Cite

Characterizing the haemodynamics in intracranial aneurysms is of high interest as it impacts aneurysm growth, rupture and treatment, especially with flow-diverting stents (FDS). Flow in these geometries is known to depend on the Dean, Reynolds and Womersley numbers, $De$ , $Re$ , $Wo$ , but is also influenced by geometrical parameters such as the sac shape or the size of the opening. Via particle image velocimetry, this parametric study aimed at evaluating the combined effects of $Re$ , $De$ , $Wo$ and the geometry of the aneurysmal sac on the haemodynamics before and after treatment with FDS. Eight ellipsoidal idealized aneurysm models were created with two curvatures of the parent vessel, two aspect ratios of the sac and two neck sizes. Before treatment, a single counter-rotating vortex, whose strength increases with $Re$ and $De$ , as well as with the neck size and the aspect ratio, was observed in the sac for all but one geometry. After treatment with FDS, four different flow topologies were observed, depending on the geometry: no separation, separation for part of the cycle, two opposing vortices or a single counter-rotating vortex. A linear model with interaction revealed the predominant effect of $De$ and the curvature of the parent vessel on the haemodynamics before and after treatment. This work once more demonstrated the primary role of haemodynamics in the treatment of intracranial aneurysms with FDS. Future work will consider the complexity of patient-specific geometries, and their effects on both the haemodynamics in the sac and the porosity of the FDS.

show abstract

Model blood for simulating red thrombus formation owing to stagnant blood flow using hypercoagulable skim milk solution

TAJIKAWA,

HIRONO,

TANAKA

et al. 2024

JBSE

Self Cite

View full text Add to dashboard Cite

The thrombus formation process has yet to be fully simulated, which necessitates the design of a novel method for the quantitative assessment of device thrombogenicity that complements animal experiments/ex vivo experiments using animal blood and computational fluid dynamics analysis. This study aimed to develop a model blood capable of simulating the formation of red thrombus owing to stagnation of blood flow by applying the phenomenon of milk clot formation. To render the rheological properties of skim milk solution used as a model blood closer to those of human blood, the ratio of the amounts of casein in skim milk, calcium chloride, and rennet (constituents of the solution of the model blood) was varied and the rheological properties of the clot formation process of human blood and skim milk solution were measured using a cone-plate viscometer. Comparisons of the rheological properties of human blood and skim milk solutions during clotting revealed that during clot formation of human blood, four characteristic quantities of the time-series change in rheological properties were observed: the viscosity before clotting, coagulation start time, viscosity increase rate, and first yield viscosity. Further, hypercoagulable skim milk solutions with rheological properties similar to those of human blood were prepared by adjusting the solution composition ratio. When this model blood was circulated in a closed-loop circuit with a saccular aneurysm model, the growth rate of skim milk clot formation in the aneurysm model was significantly different in a flow diverter stent model and a micro-porous covered stent. The variation in porosity between these two stent models has a direct impact on the rate of embolisation. The proposed blood model can effectively replicate the formation of red thrombus, providing a valuable means to accurately and quantitatively assess the therapeutic efficacy of embolisation devices.

show abstract

Hydrodynamical evaluation of microporous covered stent for the treatment of intracranial aneurysms: Comparison of flow reduction property with flow diverter stent by using particle imaging velocimetry and in vitro flow simulator

Cited by 5 publications

References 16 publications

In vitro hydrodynamical study on aneurysmal morphology for treating intracranial aneurysms using particle imaging velocimetry

In vitro hydrodynamical study on aneurysmal morphology for treating intracranial aneurysms using particle imaging velocimetry

Fluid dynamics in intracranial aneurysms treated with flow-diverting stents: effect of multiple geometrical parameters

Model blood for simulating red thrombus formation owing to stagnant blood flow using hypercoagulable skim milk solution

Contact Info

Product

Resources

About