Introduction: Saccular aneurysms of the basilar apex pose a high rupture risk. Microsurgical treatment has significant morbidity while stent-coiling has high recurrence rates. Reports of flow diversion for basilar apex aneurysms are limited.

Methods: A prospective, IRB-approved database was analyzed for all patients with basilar apex aneurysms treated with flow diversion. Patients were maintained on dual anti-platelet therapy with Aspirin and Clopidogrel or Prasugrel for Clopidogrel hypo-responders (P2Y12 above 200).

Results: A total of 7 patients with basilar apex aneurysms were treated with PED. All were female with average age 49 years and aneurysm size 7.7mm. One aneurysm was previously ruptured and coiled and 6 were incidentally discovered. A single PED was used in all cases with adjunctive coiling in 3 cases. Balloon remodeling was utilized in 2 cases. Radiographic evidence of platelet aggregation was observed in 2 cases, which resolved with intra-arterial abciximab without clinical consequence. One patient (14%) developed dysphagia and hemiparesis two weeks after treatment; MRI showed thalamic and pontine perforator ischemia that led to the patient’s death. All other patients were followed clinically for at least 6 months. Follow-up angiography was available for 4/6 (67%) patients and showed complete occlusion in 75% (3/4) at 6 months and 100% (2/2) at 12 months. In addition, there were 7 cases of distal posterior circulation aneurysms (1 VBJ, 2 mid-basilar, 2 SCA, and 2 PCA) treated with PED in which the device covered the basilar apex. One patient in this group (14%) with a mid-basilar aneurysm developed hemiparesis on post-procedure day 2; MRI showed pontine infarcts and the patient remained mRS 4 at last follow-up one year after treatment.

Conclusions: Reports of flow diversion across the basilar apex are limited. Our preliminary experience suggests it can be carried out with morbidity comparable to existing alternative microsurgical and endovascular treatments.

Patient Care: Treatment of basilar apex aneurysms poses significant challenges to the cerebrovascular neurosurgeon, and the research presented here seeks to improve patient care through improved understanding of the clinical ramifications associated with flow diversion across basilar apex aneurysms.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the efficacy and risks associated with the Pipeline embolization device (PED) for the treatment of basilar apex aneurysms; 2) Discuss, in small groups, how PED embolization compares to existing microsurgical and available endovascular modalities for the treatment of challenging basilar apex aneurysms.

References: 1. Phillips TJ, Wenderoth JD, Phatouros CC, Rice H, Singh TP, Devilliers L, Wycoco V, Meckel S, McAuliffe W. Safety of the pipeline embolization device in treatment of posterior circulation aneurysms. AJNR Am J Neuroradiol. 2012 Aug;33(7):1225-31. doi: 10.3174/ajnr.A3166. Epub 2012 Jun 7. 2. Brinjikji W, Murad MH, Lanzino G, Cloft HJ, Kallmes DF. Endovascular treatment of intracranial aneurysms with flow diverters: a meta-analysis.