The utility of low shape memory coil as first coil during stent-assisted embolization in wide-necked and bilobulated cerebral aneurysm model

Abstract

• Abstract • Objective: Coil embolization for wide-necked and bilobulated aneurysms remains a technical challenge even with stent assistance. Stent assistance prevents coil protrusion to the parent vessel, but restricts microcatheter movement. The restriction of microcatheter movement makes the role of the coil's shape memory important on the coil distribution within the aneurysm. We aimed to determine which coils are appropriate for wide-necked and bilobulated aneurysms with stent assistance by investigating the distribution of coils with differing shape memory. Methods: A silicone bilobulated aneurysm model was used to compare three types of coils (ED coil Infini, Axium Helix, and Axium 3D). Coil performance was assessed using three parameters: (1) the effect of stent assistance on coil distribution, (2) the difference in first coil distribution caused by a difference in shape memory, and (3) the influence of first coil distribution on second coil distribution. Results: Without stent assistance, coil protrusion into the parent vessel was detected immediately after beginning coil insertion for ED coil Infini; however, this coil protrusion was prevented using stent assistance. With stent assistance, the lowest shape memory coil resulted in the most homogenous distribution. The distribution of second coil was influenced by first coil. Conclusion: Without stent assistance, low shape memory coil was more likely to prolapse into the parent vessel compared to higher shape memory coil. When combined with a stent, the low shape memory coil demonstrated more homogenous distribution of the aneurysm compared to the higher shape memory coil, and allowed denser packing.•