Hemodynamic Differences Between Recurrent and Nonrecurrent Intracranial Aneurysms: Fluid Dynamics Simulations Based on MR Angiography

Abstract

Although the role of wall shear stress (WSS) in the initiation, growth, and rupture of intracranial aneurysms has been well studied, its influence on aneurysm recurrence after endovascular treatment requires further investigation. We aimed to compare WSS at necks of recurrent and nonrecurrent aneurysms. METHODS: Nine recurrent coil-embolized aneurysms were identified and matched with nine nonrecurrent aneurysms. Patientspecific vessel geometries reconstructed from follow-up 3-D time-of-flight magnetic resonance angiography were analyzed using computational fluid dynamics (CFD) simulations. Absolute WSS and the percentage of abnormally low and high WSS at the aneurysm neck compared to the near artery were measured. RESULTS: The median percentage of abnormal WSS at the aneurysm neck was 49.3% for recurrent and 34.7% for nonrecurrent aneurysms (P = .011). The area under the receiver-operating-characteristic curve for distinguishing these aneurysms according to the percentage of abnormal WSS was .86 (95% CI .62 to .98). The optimal cut-off value of 45.1% resulted in a sensitivity and a specificity of 88.89% (95% CI 51.8% to 99.7%). CONCLUSION:Our findings indicate that necks of recurrent aneurysms are exposed to abnormal WSS to a larger extent. Abnormal WSS may serve as a metric to distinguish them from nonrecurrent aneurysms with CFD simulations a priori.

Cerebral aneurysms at major arterial bifurcations are associated with the arterial branch forming a smaller angle with the parent artery

“…The attenuation of hemodynamic stresses on the bifurcation apex caused by stent deployment may decrease the stresses for aneurysm recurrence. Recent CFD studies investigating hemodynamic stresses for aneurysm recurrence supported this theory, and recurrent aneurysms had greater WSS and flow velocity besides formation of small vortex at the aneurysm neck than non-recurrent aneurysms 32 – 35 . To be specific, stenting can displace the site of aneurysm initiation according to our study and decrease the abnormally-enhanced hemodynamic stresses and subsequent wall damage on the branch.…”

RETRACTED: Paroxetine, a P2X4 inhibitor, prevents cerebral aneurysm growth as well as recanalization after coil embolization of aneurysms: the NHO Drug for Aneurysm Study

“…However, the hemodynamic environment after coil embolization is poorly understood. This may be largely due to the di culty of reproducing the threedimensional structure inside the aneurysm after embolization due to the complex geometry of the coils; indeed, only computational uid dynamics analysis using a pseudo-model is currently available for such analysis [33,34].…”

Impact of fetal-type posterior cerebral artery on recanalization of posterior communicating artery aneurysms after coil embolization: matched-pair case–control study

“…Various risk factors implicated include lesion size and neck width, posterior location, and low packing density 2–4. In the recanalization of coiled aneurysms involving vascular anatomic variants, recently published studies indicate that hemodynamic stress is critical,5 6 although the underlying mechanisms and subsequent effects remain obscure.…”