Delayed coil migration from a small wide-necked aneurysm after stent-assisted embolization: case report and literature review

Introduction: We present a previously unreported complication following the treatment of a patient with two small, wide-necked, posterior communicating artery aneurysms. Methods: Endovascular embolization of one aneurysm was performed using a stent-assisted technique. Follow-up angiography 5 months later revealed that a coil had escaped the confinement of the stent and migrated distally without occluding any arterial branches or causing symptoms. This case report demonstrates that although a rare occurrence, a coil can break loose from the stent. Discussion: We discuss the potential mechanisms of this phenomenon and review the literature on stent-assisted aneurysm coiling in order to raise awareness of this event when embolizing small, wide-necked aneurysms with a stent-assisted technique.