Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography

Initiation, growth, and rupture of cerebral aneurysms are caused by hemodynamic factors. It is extensively accepted that the cerebral aneurysm wall is assumed to be rigid using computational fluid dynamics (CFD). Furthermore, fluid-structure interactions have been recently applied for simulation of an elastic cerebral aneurysm model. Herein, we examined cerebral aneurysm hemodynamics in a realistic moving boundary deformation model based on 4-dimensional computed tomographic angiography (4D-CTA) obtained by high time-resolution using numerical simulation. The aneurysm of the realistic moving deformation model based on 4D-CTA at each phase was constructed. The effect of small wall deformation on hemodynamic characteristics might be interested. So, four hemodynamic factors (wall shear stress, wall shear stress divergence, oscillatory shear index and residual residence time) were determined from the numerical simulation, and their behaviors were assessed in the basilar bifurcation aneurysm.

More to it than meets the eye: a case report of incomitant esotropia in a child caused by a giant basilar aneurysm

Background:Esotropia is a common concern in pediatric ophthalmology consultations.While most cases stem from strabismus,it is crucial for physicians to differentiate atypical features that might indicate underlying organic causes,such as VI nerve palsy,hinting at the presence of intracranial spaceoccupying lesions.Although the occurrence of cerebral aneurysms in children is rare,they can have severe consequences.Case Description:Here,we described an extremely rare case of giant basilar fusiform aneurysm measuring 4.0 cm×3.9 cm×3.9 cm in an otherwise healthy 8-year-old child,and analyzed its atypical features that suggested an intracranial etiology.We further described an endovascular approach,performed by interventional radiologists,and discussed its advantages over the conventional neurosurgery.The patient continued to be followed by our multidisciplinary team.He had a stable post-operative course and made an excellent recovery neurologically.At the 1-year follow-up,he was orthophoria with excellent vision and stereopsis.Conclusions:To our knowledge,this is the first pediatric case in Canada where a giant intracranial aneurysm was treated endovascularly.The salient red flags—progressive incomitant esotropia and diplopia,the presence of myopia(rather than hyperopia),nystagmus and abnormal saccadic movements—should be astutely recognized by clinicians as intracranial giant aneurysms carry a poor prognosis.A multidisciplinary approach is essential for the management of such cases.

Analysis of the Risk of Basilar Aneurysm Rupture Based on CTA Morphological Parameters

Objective:To investigate morphological risk factors of basilar aneurysm rupture based on computer tomography angiography(CTA)parameters.Materials and methods:The clinical and CTA data of 43 patients with basilar aneurysm admitted to Shaanxi Provincial People's Hospital from January 2015 to July 2023 were analyzed.The patients were divided into“ruptured group”and“unruptured group,”and the morphological parameters of aneurysms were measured.The general data and morphological parameters between the two groups were statistically analyzed.Logistic regression was used to analyzed statistically significant parameters,and the receiver operating characteristic curve was drawn to evaluate its diagnostic effectiveness.Results:Irregular aneurysms were more likely to rupture than regular aneurysms(χ^(2)=13.971,P<0.05).The maximum diameter(4.92[3.37-6.94]mm),length-width ratio(1.31[1.14-1.55]),height(4.08[2.71-5.34]mm),aspect ratio(0.99[0.84-1.45]),and inflow angle(133.63±11.21°)of aneurysms in the ruptured group were larger than the unruptured group,and the differences were statistically significant(P<0.05).Binary logistic regression showed that aneurysm shape(OR=39.347,P=0.021),length-width ratio(OR=313.062,P=0.033),and inflow angle(OR=1.156,P=0.004)were independent risk factors for rupture.The area under the curve were 0.809,0.842.and 0.894,respectively.Conclusion:Aneurysm shape,aspect ratio,and blood flow incidence angle are independent risk factors for basilar aneurysm rupture,which means that they can be used to predict the risk of rupture to a certain extent.

Influence of high-porosity mesh stent on hemodynamics of intracranial aneurysm:A computational study

This paper studies the influence of a High-Porosity Mesh （HPM） stent on the hemodynamic characteristics in the intracranial aneurysm based on the Computational Fluid Dynamics （CFD）. An idealized basilar tip aneurysm model and a HPM stent model are built. The pulsating blood flow in a cardiac cycle is computationally simulated for non-stented and stented models, to provide a wealth of information of the spatio-temporally varying blood flow field. The influence of the stent placement on the hemodynamic characteristics is analyzed in terms of distributions of velocity, pressure, Wall Shear Stress （WSS） and Energy Loss （EL）, which are believed to play an important role in the development and rupture of the aneurysm. The numerical results clearly show that the velocity, pressure, WSS and EL of the blood flow in the aneurysm are reduced by 30%-40% when the HPM stent is implanted. These computational results may provide valuable hemodynamic information for clinical neurosurgeon.