Droplet simulation for cerebral aneurysm embolization

To prevent subarachnoid hemorrhage that causes serious damage to the brain, clipping and coil embolization are used in Japan, while liquid embolization is also used in overseas. Liquid embolization is an effective technique that can treat with a distorted and enormous cerebral aneurysm. However, it is not authorized yet in Japan because the embolic material flows out of the aneurysm, and embolizes normal blood vessels too. Then, as a preliminary simulation to verify the safety of liquid embolization surgery, we have been developing a particle-based high precision liquid injection simulation with CFD (Computational Fluid Dynamics), and have verified the accuracy by comparison between the simulation results with the corresponding physical experiments. The simulation size, however, was smaller than the physical experiment, since larger size simulation needs huge amount of memory, which cannot be treated with a normal PC. As the result of the simulation, a droplet was formed, but contacted the side surface of the water tank that imitated an aneurysm, and the quantitative assessment could not be performed. Therefore, this paper describes the simulation result with a larger size of environment, and the quantitative assessment by comparison of the aspect ratio of the droplet between the simulation and the physical experiment. In the assessment, we have confirmed that the shape of the droplet formed in the simulation is similar to the one of the physical experiment.