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Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models.

Tsang AC, Lai SS, Chung WC, Tang AY, Leung GK, Poon AK, Yu AC, Chow KW - Ultrasonography (2015)

Bottom Line: Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations.Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography.The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.

ABSTRACT

Purpose: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms.

Methods: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations.

Results: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography.

Conclusion: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

No MeSH data available.


Related in: MedlinePlus

Computational velocity contour plots and color Doppler ultrasonography before and after flow-diverter treatment.Compared to the values before treatment (A, B, E, F), the measurements taken with color Doppler ultrasonography after flow-diverter deployment demonstrate a dramatic reduction in intra-aneurysmal flow (D, H). These results are qualitatively and quantitatively similar to those obtained in the computer simulations (C, G) for both patients. Preop, preoperative; Postop, postoperative.
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f4-usg-14063: Computational velocity contour plots and color Doppler ultrasonography before and after flow-diverter treatment.Compared to the values before treatment (A, B, E, F), the measurements taken with color Doppler ultrasonography after flow-diverter deployment demonstrate a dramatic reduction in intra-aneurysmal flow (D, H). These results are qualitatively and quantitatively similar to those obtained in the computer simulations (C, G) for both patients. Preop, preoperative; Postop, postoperative.

Mentions: In patient 2, the measured peak systolic velocities in the inlet ICA and the first quadrant of the aneurysm before PED treatment were 36.9±1.3 cm/sec and 15.2±1.5 cm/sec, respectively, corresponding to results of 35.0 cm/sec and 15.5 cm/sec from CFD simulations at the same locations. After PED treatment, the peak systolic velocities at ICA and the first quadrant of the aneurysm became 39.6±1.5 cm/sec and <1.0 cm/sec, again concurring with CFD predictions of 35.9 cm/sec and -0.6 cm/sec after virtual PED treatment (Table 2). Similar agreements were found at the outlet vessels and all four quadrants of both aneurysms (Table 1). We can thus conclude that the flow waveforms and amplitudes of the velocity field obtained by pulse-wave Doppler ultrasonography at the inlet and outlet vessels, as well as the four quadrants of the aneurysms, were consistent with CFD results in both patients (Fig. 3). Further measurements with color Doppler ultrasonography demonstrated a marked reduction in intra-aneurysmal flow after PED deployment in both patients (Fig. 4B, D, F, H), which were qualitatively and quantitatively similar to the CFD simulations (Fig. 4A, C, E, G).


Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models.

Tsang AC, Lai SS, Chung WC, Tang AY, Leung GK, Poon AK, Yu AC, Chow KW - Ultrasonography (2015)

Computational velocity contour plots and color Doppler ultrasonography before and after flow-diverter treatment.Compared to the values before treatment (A, B, E, F), the measurements taken with color Doppler ultrasonography after flow-diverter deployment demonstrate a dramatic reduction in intra-aneurysmal flow (D, H). These results are qualitatively and quantitatively similar to those obtained in the computer simulations (C, G) for both patients. Preop, preoperative; Postop, postoperative.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4372715&req=5

f4-usg-14063: Computational velocity contour plots and color Doppler ultrasonography before and after flow-diverter treatment.Compared to the values before treatment (A, B, E, F), the measurements taken with color Doppler ultrasonography after flow-diverter deployment demonstrate a dramatic reduction in intra-aneurysmal flow (D, H). These results are qualitatively and quantitatively similar to those obtained in the computer simulations (C, G) for both patients. Preop, preoperative; Postop, postoperative.
Mentions: In patient 2, the measured peak systolic velocities in the inlet ICA and the first quadrant of the aneurysm before PED treatment were 36.9±1.3 cm/sec and 15.2±1.5 cm/sec, respectively, corresponding to results of 35.0 cm/sec and 15.5 cm/sec from CFD simulations at the same locations. After PED treatment, the peak systolic velocities at ICA and the first quadrant of the aneurysm became 39.6±1.5 cm/sec and <1.0 cm/sec, again concurring with CFD predictions of 35.9 cm/sec and -0.6 cm/sec after virtual PED treatment (Table 2). Similar agreements were found at the outlet vessels and all four quadrants of both aneurysms (Table 1). We can thus conclude that the flow waveforms and amplitudes of the velocity field obtained by pulse-wave Doppler ultrasonography at the inlet and outlet vessels, as well as the four quadrants of the aneurysms, were consistent with CFD results in both patients (Fig. 3). Further measurements with color Doppler ultrasonography demonstrated a marked reduction in intra-aneurysmal flow after PED deployment in both patients (Fig. 4B, D, F, H), which were qualitatively and quantitatively similar to the CFD simulations (Fig. 4A, C, E, G).

Bottom Line: Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations.Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography.The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.

ABSTRACT

Purpose: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms.

Methods: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations.

Results: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography.

Conclusion: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

No MeSH data available.


Related in: MedlinePlus