1136. Management of Posterior Circulation Fusiform Aneurysms

Authors: Ephraim W. Church, MD; Mark Bigder, MD; Eric Sussman, MD; Gary Steinberg, MD, PhD (Stanford, CA)

Introduction: Posterior circulation fusiform aneurysms can present with subarachnoid hemorrhage (SAH), symptoms from mass effect, or unrelated symptoms. Numerous vital perforator arteries, absence of discrete aneurysm neck, and the often large and extensive nature of these lesions make them some of the most challenging aneurysms to treat. There have been advances in both microsurgical and endovascular approaches including flow diversion, and we sought to review these approaches in a long term series at our medical center. Methods: We performed an extensive chart review from 1990-2017. Pretreatment and post treatment modified Rankin Scores and Glasgow Outcome Scores (GOS) were collected. Using regression techniques, we examined key independent and dependent variables including presenting features, aneurysm location and size, surgical approach and complications, and pretreatment and post treatment thrombosis. The study was approved by our IRB. Results: There were 84 patients with mean age 54 (range 11-86) and male to female ratio 0.7:1. Forty-one patients presented with SAH. Aneurysms were located on the vertebral artery or posterior inferior cerebral artery in 50 patients, basilar artery or vertebrobasilar junction (VBJ) in 22, and posterior cerebral artery in 12. Thirty-one patients were treated with microsurgical approaches and 53 with endovascular techniques. Six aneurysms were treated with flow diversion. We found good 30 day outcomes (GOS 4-5) in 82%, poor outcomes (GOS 2-3) in 13%, and 5% died. Overall neurological complication rate was 16%. In the initial regression analysis, poor outcome was predicted by age, basilar and VBJ location, SAH, and incomplete thrombosis after endovascular treatment. Conclusion: Posterior circulation fusiform aneurysms remain a challenging aneurysm subtype. While flow diversion is a useful addition to the armamentarium, traditional endovascular and microsurgical techniques continue to offer effective alternatives.