Evaluation of effect of aneurysm model material on coil contact force and catheter movement

Abstract

To ensure safe coil embolization for cerebral aneurysms, it is important to investigate the contact force between a coil and an aneurysm wall. Therefore, in our previous study, we developed an experimental system for measuring the contact force between a coil and an aneurysm biomodel. However, because the aneurysm model was made of silicone rubber, its physical properties, such as the friction coefficient, differed from those of aneurysms in vivo. Therefore, in this study, we made an aneurysm model using poly (vinyl alcohol) hydrogel (PVA-H) and evaluated the effect of the model material on the contact force. In addition, we acquired images during the experiment and evaluated the behavior of the coil and catheter and the relationship between the catheter movement and the contact force. A commercially available coil was inserted through a catheter into two types of aneurysm models (silicone rubber and PVA-H), and the effects of the model material and the catheter tip position (near dome, at the center, and near neck) were evaluated. The contact force and the total movement of the catheter tip for the PVA-H model were smaller than those for the silicone rubber model. The contact force (total catheter movement) was greater (smaller) when the catheter tip was inserted deeper into the silicone rubber model. These results suggest that the state of contact between the aneurysm and the coil affects the contact force and the catheter movement and that these two values are related.

Keywords

• endovascular treatment
• cerebral aneurysm
• coil embolization
• contact force
• catheter
• phantom
• first coil