1083. Endovascular Treatment of Large and Giant Posterior Circulation Cerebral Aneurysms: A Single Institution Case Series and Meta-Analysis

Authors: Malia McAvoy; Matthew Koch, MD; Christopher Stapleton, MD; Scott Raymond, MD; Paola Calvachi, MD, MS; Aman Patel, MD (Boston, MA)

Introduction: Despite enormous technological advancements in endovascular neurosurgery, the treatment of large and giant aneurysms in the posterior circulation remains challenging. Recent evidence regarding the outcomes of these patients undergoing endovascular treatment is lacking. Methods: We report a retrospective review of 9 patients with large or giant posterior circulation aneurysms treated endovascularly at one academic neurovascular center between 2012 and 2017. Preoperative radiology, operative details, follow-up angiography and outcomes were reviewed. A systematic review of the English literature since 2007 using PubMed, Embase Cochrane and Web of Science identified 7 reports of large or giant posterior circulation aneurysm treated endovascularly. A pooled proportion of patients was calculated for morbidity and mortality using a random effects model. Heterogeneity among the studies was assessed using the I 2 (inconsistency) statistic. Results: In our series, there were 7 (77.8%) aneurysms located within the basilar artery, one (11.1%) posterior cerebral artery aneurysm, and one (11.1%) anterior inferior cerebellar artery aneurysm. There were two (22.2%) patients who presented with subarachnoid hemorrhage (SAH). Four (44.4%) patients had additional aneurysms other than the large or giant posterior circulation aneurysm. Treatment modalities included primary coiling (2, 22.2%), stent-assisted coiling (4, 44.4%), flow diversion with the Pipeline Embolization Device (2, 22.2%), and LVIS Blue stent (1, 11.1%). Poor outcomes occurred in 5 (55.6%) patients, including 2 (22.2%) deaths, 2 (22.2%) procedure-related strokes and one (11.1%) post-procedural hemorrhage with secondary hydrocephalus. None of these 5 patients had presented with SAH. Within the 7 literature reports, the pooled proportion of patients with morbidity was 0.22 (95% CI 0.12-0.36) and for mortality was 0.23 (95% CI 0.12-0.40). Conclusion: Outcomes after endovascular treatment of large or giant posterior circulation aneurysms remains poor. Further advances in endovascular technologies are necessary for improved outcomes in these lesions.