A Case of Coil Embolization for an Angiographically Occult Ruptured Anterior Communicating Artery Aneurysm.

Objective: We report a case in which coil embolization was performed for an angiographically occult ruptured anterior communicating artery aneurysm (Acom AN).

Case presentation: A 91-year-old man was admitted to our hospital because of sudden deterioration of consciousness. Computed tomography (CT) revealed a diffuse subarachnoid hemorrhage in the basal cisterns, and CT angiography identified a 5-mm Acom AN. The next day, a catheter angiogram slightly visualized the neck portion of the Acom AN, despite no apparent visualization of the aneurysmal sac. We suspected intraluminal thrombosis of ruptured Acom AN, and intraaneurysmal coil embolization was performed to prevent re-rupture. By referring to the size and projection of the aneurysmal sac on CT angiography, a microcatheter was guided into the neck portion, and 3 platinum coils were successfully placed within the aneurysm without any complications. Eight days after coil embolization, recanalization of the aneurysm was suspected on magnetic resonance imaging (MRI). Another MRI obtained 17 days after coil embolization revealed gradual recanalization of the aneurysm, which was confirmed on catheter angiogram obtained 22 days after coil embolization. Additional intraaneurysmal coil embolization resulted in complete occlusion. Subsequently, the patient had an uneventful course without rebleeding and was transferred to a rehabilitation center.

Conclusion: We performed intraaneurysmal coil embolization for an angiographically occult ruptured Acom AN by referencing the neck position, aneurysm projection, and aneurysm size on CT angiography. Thus, angiographically occult aneurysms can be treated with endovascular coil embolization despite the need for close follow-up studies to detect recanalization.