A proposed design of flow diverter and it’s hemodynamic validation

Abstract

Flow diverter intervention is a cutting-edge treatment for intracranial aneurysms by altering the flow field and reducing the pressure in the aneurysm sac. However, the rupture rate and complications rate are still high. In this study, a new design of flow diverter based on Bernoulli’s equation was proposed and hemodynamics evaluation of it was conducted. The numerical model of a patient specific internal carotid aneurysm was established based on computed tomography scan images (Model C). The aneurysm models with normal diverter (ND) and local stenosed diverter (LSD) were modified from the patient-specific model. The blood flow characteristics were obtained and analyzed by numerical simulation while the in vitro experiments were conducted using three-dimensional printed silicone models and pressure measurement system. In both ND and LSD models, the blood flow into the aneurysm have been significantly blocked by the diverters and the pressure in the aneurysm sac have been decreased. The pressure drop and the wall shear stress on the aneurysm wall in the LSD model are higher than that in the ND model. The oscillatory shear index and relative residence time in the aneurysm wall of LSD are lower than that in the ND model. The pressure measurement in the vitro experiment also qualitatively verified the results of pressure comparison in the numerical simulation. In conclusion, the simulation results and in vitro experiments verified that diverter can certainly reduce the pressure in the aneurysm, and the newly design diverter with local stenosis can strengthening this effect.

Keywords

• Intracranial aneurysm
• Diverter
• Hemodynamics
• Local stenosed diverter
• Pressure