Endovascular Treatment of Ruptured Intracranial Blister Aneurysms: A Systematic Review and Meta-analysis

Background: Endovascular treatment of blister aneurysms is a promising approach, even though they are vascular lesions challenging to treat due to their angioarchitectural characteristics. Purpose: Our aim was to investigate clinical and radiologic outcomes after endovascular treatment of ruptured blister aneurysms. Data sources: PubMed, Ovid MEDLINE, Ovid EMBASE, Scopus, and the Web of Science were screened. Study selection: We performed a comprehensive review of the literature from 2010 to 2019 reporting series of patients with blister aneurysms treated with an endovascular approach. Data analysis: Event rates were pooled across studies using a random effects meta-analysis. Data synthesis: A total of 32 studies reporting on 684 patients (707 aneurysms) were included. Stent placement, stent-assisted coiling, and flow diversion were the most commonly described treatments (282, 256, and 155 patients, respectively). The long-term complete occlusion rate was 76.9% (95% CI, 69.2%-83.9%). The perioperative complication rate was 8.9%, and clinical outcome at final follow-up was mRS <2 in 76.6% (95% CI, 68.2%-84.2%) of patients. The mortality rate was 4.7% (95% CI, 2.30%-7.80%). Among the different techniques, stent-assisted coiling is the one that had the higher rate of immediate occlusion (63.4%); however, the occlusion rate at the final follow-up was comparable among the different techniques. Limitations: Different techniques were described and data were reported in a nonhomogeneous way, possibly representing a bias in the present study. Conclusions: This study suggests that endovascular treatment of blister aneurysms is associated with good long-term occlusion rates and reasonable complication and mortality rates. There is no consensus on the best endovascular techniques in blister aneurysm management.