Numerical study of liquid embolization in intravascular treatment using a moving particle semi-implicit method

Subarachnoid hemorrhage is caused mainly by cerebral aneurysm rupture. Since subarachnoid hemorrhage has not only high mortality but also high possibility for complications, it is important to prevent aneurysm rupturing by performing an intravascular treatment. The advantage of the recently developed photocurable liquid embolization is its controllability compared to conventional treatment such as coiling or clipping. However, as the treatment has not been evaluated extensively, this study presents a numerical method to investigate applicability of intravascular treatment using photocurable liquid embolization. The process of photocurable liquid embolization is complicated and involves both geometrical and topological changes like separation. Therefore, a particle method, particularly the moving particle semi-implicit method was used in this paper. In order to replicate the treatment, which involves injecting embolization liquid into blood in the aneurysm, the interfacial tension requires two types of interactions :1) the one between blood (water) and embolization liquid (viscous fluid) and 2) the other between embolization liquid (viscous fluid) and catheter (cylindrical Teflon tube) with wettability. We developed an efficient numerical method that considers the effects of highly viscous fluids of liquid embolization and wettability of a catheter. The proposed method was applied to a simplified problem by injecting highly viscous fluid to water to replicate the intravascular treatment. The simulation results were compared to experimental data and showed good agreement with the experiments.