Partial thrombosis of an anterior communicating artery aneurysm prior to endovascular coiling, with intra-procedural distal thrombus embolization.

Thromboembolic stroke from migration of thrombus formed in non-giant intracranial aneurysms is a recognized but rare event. We describe a case of partial thrombosis of a 7 mm anterior communicating artery aneurysm, which embolized to the right callosomarginal artery in the brief time interval between two sequential diagnostic angiograms performed as part of elective endovascular coiling, and before any instrumentation had been advanced into the intracranial circulation. To our knowledge, this is the first reported case of aneurysmal thrombus embolization observed angiographically in near real time.