Treatment of blood blister-like aneurysms of the internal carotid artery with stent-assisted coil embolization

Objective: Blood blister-like aneurysms (BBAs) are tiny aneurysms arising from the non-branching sites of the anterior wall of the supra-clinoid segment of internal carotid artery. These aneurysms are quite dangerous because of the high risk of recurrent bleeding associated with their fragile neck. The optimal treatment for the BBAs is still controversial. This paper aims to evaluate the application of stent-assisted coil embolization in the treatment of BBAs. Methods: A retrospective review of the aneurysm database in our institution identified 8 patients carrying BBAs treated by stent-assisted coil embolization. The clinical characteristics, procedural data, angiographic findings, and follow-up results were analyzed and evaluated. Results: Of the eight patients, stent-assisted coil embolization was successfully performed in 5 (62.5%). Sole stent deployment was employed in two cases (25%) because the aneurysm was too small to be occluded with coils. During the procedure rupture of the aneurysm occurred in one patient when the stent was successfully delivered and the coil was used with an attempt to fill the aneurysmal cavity, and, therefore, the occlusion of internal carotid artery had to be carried out in this patient. The modified Rankin Scale score at the time of discharge in the alive patients was 1 (n = 4), 2 (n = 1) or 3 (n = 1). Two patients died due to post-operative bleeding (25%). The modified Rankin Scale score at 9-36 months (mean 21.5 months) after the treatment was 0 in 4 patients, 1 in 1 patient, and 2 in 1 patient. Angiographic checkup was made in all patients during the following-up period, and reoccurrence of the aneurysm was observed in three cases, who had to accept endovascular treatment once more. Conclusion: Stent-assisted coil embolization is one of the feasible methods for the treatment of BBAs. It is quite safe to employ this technique in the acute stage of BBAs and,moreover, this therapy can markedly reduce the mortality. It is possible that the application of multiple stents or newly-developed low porosity stents may further reduce the risk of re-bleeding or reoccurrence. (authors)