Intra-aneurysmal Onyx embolization for distal aneurysms of the cerebellar arteries

Distal cerebellar artery aneurysms are difficult to treat both surgically and endovascularly. The purpose of this study is to assess the efficacy and safety of intra-aneurysmal Onyx embolization of these lesions with parent artery preservation.

Ten consecutive patients harboring 10 distal cerebellar aneurysms were treated with intra-aneurysmal Onyx embolization. Locations of the aneurysms were as follows: superior cerebellar artery in three patients, anterior inferior cerebellar artery in two, and posterior inferior cerebellar artery in five. The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated.

In every case, endovascular treatment was achieved. Immediate angiography demonstrated that all of 10 aneurysms were completely occluded, with parent artery preservation in nine of them. Procedure-related complication occurred in one patient with transient neurological sequelae. None of the treated aneurysms experienced rebleeding or recanalization during the follow-up time (mean, 12·7 months).

We found that the intra-aneurysmal Onyx embolization was helpful in the treatment of distal cerebellar aneurysms in which selective occlusion of the aneurysmal sac with coils or open clipping cannot be achieved.