Case report: A 33-year-old woman was admitted for evaluation of vertigo. An unruptured fusiform aneurysm of left distal posterior inferior cerebellar artery was found and presumed to be the cause of her vertigo. The aneurysm was clipped using three clips and then the vertigo was relieved. However, she developed low back pain 53 months after the operation. On plain radiographic examination, a right-angled clip was found at the sacral level. Cerebral angiography revealed two clips remaining at the previous location and previous aneurysm was no longer visualized. Her symptom of back pain was resolved spontaneously over 2 weeks, and she is doing well without any particular inconvenience for following 72 months.
Discussion: Clip loosening and migration is an extremely rare event in aneurysm surgery. If the aneurysm is secured and symptoms related to a migrated clip is resolved, the removal of one does not seem to be mandatory.