Flow diverter treatment of cerebral blister aneurysms

Blood blister-like aneurysms (BBA) are small, friable, broad-based aneurysms that represent high risk for rerupture. Treatment of BBA is challenging, and may include surgical wrapping, clipping, multiple overlapping stents, and/or coiling. Flow diversion is a rapidly evolving treatment strategy for intracranial aneurysms, but the evidence for its use in cases of BBA is scarce.

A retrospective review of flow-diverter-treated, ruptured BBA cases at our tertiary care institution was undertaken. Clinical, imaging, procedural, and mid-term follow-up data on the patients were collected.

Eight patients underwent flow-diverter stent treatment for ruptured BBA. Median age at time of treatment was 49 years (interquartile range [IQR] 42-57) with five females (62.5%). The most common location of the BBA was the supraclinoid segment of the internal carotid artery. The median Hunt-Hess score was 2 (IQR 1.7-3.2). All patients were treated with dual anti-platelet therapy. Good clinical outcomes (modified Rankin score 0-2) were seen in 6/7 (85.7%) patients with available follow-up at 1 year. Complete occlusion of the aneurysm on latest angiogram (7) or MRI (1) was seen in 6/8 (75%) patients (at a median of 8 months). No patient had rerupture, retreatment, or recurrence of the aneurysm.

Flow-diverter stents may be a feasible treatment option for BBAs. They offer high occlusion and low retreatment rates with good mid-term outcomes, but the long-term efficacy remains unknown. Also, dual anti-platelet therapy in the acute ruptured setting can be challenging.