PURPOSE: N-butyl-2-cyanoacrylate (NBCA) and Lipiodol mixture (NL) are widely used for emergency embolization due to their effective polymerization upon contact with blood. However, NBCA's strong adhesive properties can cause complications, leading to the development of an NBCA-Lipiodol-ethanol mixture (NLE), which has shown reduced catheter adhesion. This study aimed to observe the structural differences between NL and NLE polymers using scanning electron microscopy. MATERIALS AND METHODS: Four different ratios of NBCA, Lipiodol, and ethanol (NLE230, NLE221, NLE150, and NLE141) were examined. The samples were injected into silicone tubes filled with human serum, and the polymerized specimens were collected and observed using scanning electron microscopy. RESULTS: NLE230 formed a dense, three-dimensional honeycomb-like structure, whereas NLE221 exhibited a two-dimensional folded-sheet structure. Both NLE150 and NLE141 exhibited a folded-sheet structure
however, NLE141 was considerably more fragile, with cracks and rough surfaces, resulting in a structure that lacked uniformity. CONCLUSION: The differences in structure suggest that ethanol considerably influences the polymerization process. These differences may explain characteristics of NLE, such as low adhesion.