Delayed symptomatic coil migration after initially successful balloon-assisted aneurysm coiling: technical case report.

Objective: To describe delayed migration of a coil loop after adjunctive balloon remodeling of an anterior communicating artery aneurysm.
Methods: A 56-year-old man with a subarachnoid hemorrhage from a small anterior communicating artery aneurysm underwent successful coil embolization with adjunctive balloon remodeling.
Results: Eight days after the procedure, the patient returned with the acute onset of right lower extremity paralysis. Magnetic resonance imaging demonstrated an acute left anterior cerebral artery territory infarction. Angiography demonstrated that this infarct was secondary to the delayed migration of a coil loop out of the aneurysm and into the left A1 to A2 junction.
Conclusion: Delayed migration of a coil loop after adjunctive balloon remodeling represents a rare but potentially severe complication of this technique.