ABSTRACT
OBJECT: The rupture risk of cerebral aneurysms is determined by various factors. However, it is not clear whether the thickness of the aneurysm wall also influences the rupture risk. In this study, under the assumption that thin-walled aneurysms have a higher rupture risk compared with thick-wall aneurysms, we evaluate the usefulness of computed fluid dynamics(CFD)to identify thin-walled cerebral aneurysms. METHODS: Fifty-four unruptured middle cerebral aneurysms from 53 patients were analyzed using CFD before the operation. We divided these aneurysms into two groups: translucent-type aneurysms and others. To analyze the difference of these groups, individual elements(age, gender, volume, and aspect ratio)and hemodynamic factors(wall shear stress[WSS], flow coefficient, and flow coefficient per volume)were examined using CFD. RESULTS: Univariate analysis detected significant relationships between the translucent-type aneurysms and gender, aspect ratio, WSS and flow coefficient per volume. Multiple logistics regression also identified a significant relationship with gender and flow coefficient per volume. The receiver operating characteristic curve demonstrated that the flow coefficient per volume could predict translucent-type aneurysms(area under the curve 0.84, cut-off value 1.32, sensitivity 76.2%, and specificity 87.9%). CONCLUSION: Gender and the flow coefficient per volume could predict translucent-type aneurysms of the middle cerebral artery. CFD analysis might be a useful tool to predict translucent-type aneurysms.
Subject(s)
Aneurysm, Ruptured , Intracranial Aneurysm , Aneurysm, Ruptured/diagnosis , Hemodynamics , Humans , Hydrodynamics , Intracranial Aneurysm/diagnosis , Middle Cerebral Artery , Stress, MechanicalABSTRACT
OBJECT: Recent studies have shown that computational fluid dynamics(CFD)analysis is useful to evaluate flow dynamics of intracranial aneurysms. However, CFD analysis still requires high costs and substantial time even now. This study aimed to evaluate whether newly developed software can shorten the time for analysis and serve useful information during clipping surgery for intracranial aneurysms. METHODS: CFD analysis was performed in 55 unruptured cerebral aneurysms in 51 patients. The time required for analysis of each aneurysm was recorded. On the basis of CFD analysis, both pressure and wall shear stress(WSS)were calculated as the values at the systolic and diastolic phases, and also the mean value through one cardiac cycle. These data were compared between thin-wall points and other points within each aneurysm. RESULTS: The average time required for analysis was 3 hours, ranging from 1 to 15 hours. The CFD data could be referenced during surgery in each patient. The pressure in about 93% and 80% of the thin-wall points was higher than that at other points within each aneurysm in the systolic and diastolic phases, respectively. However, there was no significant correlation between WSS and wall thickness in each aneurysm. CONCLUSION: This study clearly shows that newly-developed software is simple and requires much shorter time for CFD analysis than previous methods. Higher pressure through the cardiac cycle may efficiently predict a thin-wall region within intracranial aneurysms, which strongly suggests that CFD analysis would be a valuable tool to determine the treatment strategy in patients with unruptured aneurysms.
