Correlation between vertebrobasilar dolichoectasia and posterior circulation cerebral infarction in fluid structure interaction analysis

Objective: Using Fluid Structure Interaction (FSI) to analyze the relationship between the characteristics of fluid mechanics distribution and cerebral infarction in patients with different levels of vertebrobasilar dolichoectasia (VBD). Methods: All of 34 patients (62.1 ± 12.3 years old, range 25 to 80 years, 20 males and 14 females) with posterior circulation ischemia were selected in Tianjin Fourth Central Hospital, during Feb. 2015-Feb. 2017. Each patient underwent CTA and MRI, and VBD was confirmed. According to the Smoker grading standard, the VBD were divided into four levels-level 0, 1, 2, and 3. Basing on their original data of head and neck CTA, a finite-element model was built, then the model was fed into ANSYS Workbench for analysis. The wall shear stress (WSS), wall pressure (WP) and blood flow velocity were calculated. One-way ANOVA was employed to analyze the differences in hemodynamic parameters between different levels of VBD. Pearson correlation and regression analysis were conducted to evaluate the correlation between blood flow parameters and posterior circulation cerebral infarction. Results: As the level of VBD increased, the WSS and blood flow velocity were at small curved side, and the WP at large curved side were decreased (all P < 0.05); the incidence of cerebral infarction was increased (P = 0.02). The WSS and blood flow velocity at small curved side, and the WP at large curved side negatively correlated with the incidence of cerebral infarction. The correlation coefficients were -0.70, -0.58, -0.78, respectively (all P < 0.05), and the R² were 0.50, 0.63, 0.62, respectively. Conclusion: FSI analysis may characterize the hydromechanics of different levels of VBD, and can provide theoretic support for VBD research. As the level of VBD increases, hydromechanical parameters negatively correlate with incidence of posterior circulation cerebral infarction. (authors)