Influence of hemodynamics on recanalization of totally occluded intracranial aneurysms: a patient-specific computational fluid dynamic simulation study.
OBJECTIVE
Some totally occluded intracranial aneurysms may recur. The role of hemodynamic mechanisms in this process remains to be elucidated. The authors used computational fluid dynamic analysis and investigated the local hemodynamic characteristics at the aneurysm neck before and after total embolization, attempting to identify hemodynamic risk factors leading to recurrence of totally embolized aneurysms.


METHODS
Between May 2008 and June 2010, the authors recruited 17 consecutive patients with totally occluded intracranial aneurysms (7 recanalized and 10 stable lesions). Using patient-specific 3D digital subtraction angiography data, the hemodynamic features before and after embolization were retrospectively characterized.


RESULTS
The overall preembolization blood flow patterns were nearly the same in the recanalized and stable groups, with no significant difference in either the maximum wall shear stress (WSS) (p = 0.914) or the spatially averaged WSS (p = 0.322) at peak systole at the aneurysm neck. After occlusion, the overall flow pattern changed, and the WSS distribution at the treated aneurysm neck differed in the 2 groups. In all of the 7 recanalized cases, both the maximum WSS and spatially averaged WSS at peak systole at the treated aneurysm neck were higher than those at the aneurysm neck before embolization. In contrast, both parameters were decreased in 70%-80% of the stable cases. After embolization, both the maximum WSS (p = 0.021) and spatially averaged WSS (p = 0.041) at peak systole at the treated aneurysm neck were higher in the recanalized group than in the stable group.


CONCLUSIONS
Higher WSS at the treated aneurysm neck after total embolization can be an important hemodynamic factor that contributes to aneurysm recurrence after endovascular treatment.
Beijing Tiantan Hospital, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
Chuanhui
C
Li
Shengzhang
S
Wang
Jialiang
J
Chen
Hongyu
H
Yu
Ying
Y
Zhang
Fan
F
Jiang
Shiqing
S
Mu
Haiyun
H
Li
Xinjian
X
Yang
D000328:Adult; D000368:Aged; D000465:Algorithms; D015901:Angiography, Digital Subtraction; D001783:Blood Flow Velocity / Q000502:physiology; D002533:Cerebral Angiography; D003198:Computer Simulation; D004621:Embolization, Therapeutic; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D057446:Hydrodynamics; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D012307:Risk Factors; D013599:Systole / Q000502:physiology