Delayed Branching Artery Occlusion Caused by Clip Rotation after Intracranial Aneurysm Clippings.

Clip rotation after clipping is a major cause of delayed cerebral ischemia and may occur after any of several intraoperative monitoring techniques. We experienced 3 cases of clip rotation in 3 patients after clipping between March 2011 and December 2013. One of these patients has permanent motor weakness of the left upper extremity because of delayed occlusion of the right M1 lenticulostriate artery. The other two developed delayed occlusion of the frontopolar artery or of the A1 perforating artery, but did not have any neurologic deficits. Clinicians need to exercise great care not to compromise distal blood flow after clipping intracranial aneurysms. We present 3 cases in which clip rotation occurred after aneurysm clipping and progressively compromised blood flow of a nearby branching artery.