Stiff coils enhance shape retention and pressure resistance in an aneurysm model even at low volume

Purpose To elucidate the characteristics of 3 D frame coils and identify the optimal coil for visceral aneurysms. Material and methods Using a vascular model, we compared the postembolization coil distribution and repulsive force of three coils: Guglielmi detachable coil (GDC; stock wire diameter, 0.004 in; primary diameter, 0.015 in), Target XL (0.003, 0.014), and Target XXL (0.003, 0.017). Additionally, the coil area, roundness, and center of gravity were quantitatively compared. The coil repulsive force was measured by compressing the postembolization vessel model with a digital force gauge. Results There were no significant differences in the coil area and roundness among the three coil types. Compared with the Target coils, the GDC deployed evenly along the vessel wall, its center of gravity was less displaced, and although it had the lowest embolic density, its repulsive force was greater regardless of the number of coils used. Conclusions GDC coils with a larger stock wire diameter and a smaller primary diameter unfolded evenly along the wall and had a greater repulsive force. Coil stiffness contributes to coil stability and shape retention, indicating the possibility of preventing recurrence by selecting a frame coil with a focus on coil stiffness.