Background Pipeline embolization device (PED) deployment combined with coil therapy for large complex intracranial aneurysms is effective and considered superior to PED deployment alone. However, the optimal strategy for use of coils remains unclear. We used patient-specific aneurysm models and finite element analysis to determine the ideal packing density of coils after PED placement.
Methods Finite element analysis was used to provide a higher-fidelity model for accurate post-treatment computational fluid dynamics analysis to simulate the real therapeutic process of PED and all coils. We then calculated and analyzed the reduction ratio of velocity to identify the hemodynamic change during PED deployment and each coil embolization.
Results Sixteen consecutive patients underwent PED plus coil procedures to treat internal carotid artery intracranial aneurysms. After PED deployment, the intra-aneurysmal flow velocity significantly decreased (15.3 vs 10.0 cm/s; p<0.001). When the first coil was inserted, the flow velocity in the aneurysm further decreased and the reduction was significant (10.0 vs 5.3 cm/s; p<0.001). Analysis of covariance showed that the effect of the reduction ratio of velocity of the second coil was significantly lower than that of the first coil (p<0.001)—that is, when the packing density increased to 7.06%, the addition of coils produced no further hemodynamic effect.
Conclusion Adjunct coiling could improve the post-PED hemodynamic environment in treated intracranial aneurysms. However, dense packing is not necessary because the intra-aneurysmal hemodynamics tend to stabilize as the packing density reaches an average of 7.06% or after insertion of the second coil.
- flow diverter
Data availability statement
Data are available upon reasonable request. Not applicable.
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Contributors Study concept and design: JL, MZ, XY. Acquisition of data and technique support: MZ, ZT, XL, XY, JX. Analysis and interpretation of data: YZ, KW, YZ. Drafting or revising the manuscript: MZ, JL, XL. Final approval of the version to be published: JL, JX. Agreement to be accountable for all aspects of the work: MZ. Responsible for the overall content: JL.
Funding This work was supported by Beijing Municipal Administration of Hospitals Incubating Program (PX2022022), Beijing Tiantan Hospitals Authority Youth Programme (code: QML20190503), and National Natural Science Foundation of China (grant numbers: 81801156, 82072036, 81901178 and 81801158).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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