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Computational Fluid Dynamics Study of Bifurcation Aneurysms Treated with Pipeline Embolization Device: Side Branch Diameter Study.

Tang AY, Chung WC, Liu ET, Qu JQ, Tsang AC, Leung GK, Leung KM, Yu AC, Chow KW - J Med Biol Eng (2015)

Bottom Line: This may result in side-branch hypoperfusion subsequent to stenting.Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions.This quantitative analysis can assist in treatment planning and therapeutic decision-making.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, 999077 China.

ABSTRACT

An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.

No MeSH data available.


Related in: MedlinePlus

Maximum WSS at various locations varies with side branch diameter. a At distal neck, shear stress decreases with increasing side branch diameter under both pre-stenting and post-stenting conditions. b When d is large, such stress at the side branch vessel shows great drop after stenting, creating undesirable hemodynamic environment
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Fig6: Maximum WSS at various locations varies with side branch diameter. a At distal neck, shear stress decreases with increasing side branch diameter under both pre-stenting and post-stenting conditions. b When d is large, such stress at the side branch vessel shows great drop after stenting, creating undesirable hemodynamic environment

Mentions: Wall shear stress (WSS) is important in vascular biology and endothelial cell behavior. A low WSS may be undesirable and is related to atherosclerosis and plaque formation [29]. The peak WSS is analyzed for the present model to study the rupture risk of aneurysms. The peak WSS values are found to be located near the neck of the aneurysm, since the stent is situated adjacent to the neck. The variation of WSS at both the proximal and distal regions of the neck for various side branch diameters is depicted in Fig. 6a. Before surgical intervention, the WSS is lower when the side branch diameter is larger, and may be associated with a higher risk clinically [30]. After stent deployment, the WSS values at both the proximal and distal necks increase. However, for d = 2.0 mm, the WSS at the distal neck remains below the threshold of safety [29, 30], and constitutes an unfavorable environment in terms of hemodynamics.Fig. 6


Computational Fluid Dynamics Study of Bifurcation Aneurysms Treated with Pipeline Embolization Device: Side Branch Diameter Study.

Tang AY, Chung WC, Liu ET, Qu JQ, Tsang AC, Leung GK, Leung KM, Yu AC, Chow KW - J Med Biol Eng (2015)

Maximum WSS at various locations varies with side branch diameter. a At distal neck, shear stress decreases with increasing side branch diameter under both pre-stenting and post-stenting conditions. b When d is large, such stress at the side branch vessel shows great drop after stenting, creating undesirable hemodynamic environment
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig6: Maximum WSS at various locations varies with side branch diameter. a At distal neck, shear stress decreases with increasing side branch diameter under both pre-stenting and post-stenting conditions. b When d is large, such stress at the side branch vessel shows great drop after stenting, creating undesirable hemodynamic environment
Mentions: Wall shear stress (WSS) is important in vascular biology and endothelial cell behavior. A low WSS may be undesirable and is related to atherosclerosis and plaque formation [29]. The peak WSS is analyzed for the present model to study the rupture risk of aneurysms. The peak WSS values are found to be located near the neck of the aneurysm, since the stent is situated adjacent to the neck. The variation of WSS at both the proximal and distal regions of the neck for various side branch diameters is depicted in Fig. 6a. Before surgical intervention, the WSS is lower when the side branch diameter is larger, and may be associated with a higher risk clinically [30]. After stent deployment, the WSS values at both the proximal and distal necks increase. However, for d = 2.0 mm, the WSS at the distal neck remains below the threshold of safety [29, 30], and constitutes an unfavorable environment in terms of hemodynamics.Fig. 6

Bottom Line: This may result in side-branch hypoperfusion subsequent to stenting.Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions.This quantitative analysis can assist in treatment planning and therapeutic decision-making.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, 999077 China.

ABSTRACT

An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.

No MeSH data available.


Related in: MedlinePlus