Enhanced Embolization Efficacy with the Embolic Microspheres Guided by the Aggregate Gradation Theory Through In Vitro and Simulation Evaluation

Purpose Size of the embolic microspheres is of critical importance in the transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) to achieve the optimal embolization therapy. In this regard, to optimize the size distribution of the embolic microspheres and enhance the embolization efficacy, the aggregate gradation theory is used to formulate the microspheres. Methods Finite element analysis (FEA) and in vitro experiments confirmed a better embolic efficacy for the poly(vinyl alcohol) (PVA) microspheres formulated according to the aggregate gradation theory. Results The average volume flow of the graded group was 1.31 × 10 −4 mL/s in vitro experiment, which was lowest among all the groups suggesting the graded group had the optimal embolic effect. The graded group has the largest pressure gradient of 314.22 Pa/ μ m in FEA among all the groups, which can be attributed to the highest packing density of the graded group compared with other groups. Conclusions The graded embolic microspheres have a larger drag coefficient compared with the narrow size distribution groups both in vitro experiment and FEA. These findings can be used to formulate the embolic agents with optimal size distributions and are significant for the improvement of clinical embolization therapy.