A new retrieval method for an already detached coil mass in the aneurysm sac: 'Thread and catch' technique.

During endovascular coiling, unexpected procedure-related complications such as coil misplacement have been reported, and these complications may induce emboli or thrombotic vessel occlusion. A malpositioned detached coil contained and immobilized within an intracranial aneurysm is difficult to remove using current methods. We report an effective retrieval technique for detached coils. The 'thread and catch technique' can be used when the malpositioned detached coil is immobilized within the aneurysm.