Introduction Unintended side branch occlusions after Flow Diversion device insertion (FD) for the treatment of intracranial arterial aneurysms have been reported for up to 15% of patients. Fortunately, the incidence of symptomatic side branch occlusion after FD appears to be more rare. However, it could be devastating if the side branch occlusion involves the anterior choroidal artery. We aim to review the incidence of angiographic occlusion rates of the anterior choroidal artery following coverage with FD and its clinical consequences.

Methods A retrospective review of distal ICA aneurysms (cavernous, ophthalmic, posterior communicating, and anterior choroidal artery) treated with FD at our institution since 2018 was performed. Coverage of anterior choroidal arteries and its patency was determined based on immediate post-endovascular treatment angiography and on the follow up diagnostic angiography, respectively. Clinical symptom was determined based on clinical examination. All patients received dual antiplatelet therapy before the endovascular treatment and for several months after the treatment. On the day of the procedure, Thromboelastogramy (TEG) was used to determine arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition. Each patient’s antiplatelet therapy was tailored or modified based on this testing.

Results The Anterior Choroidal Artery was covered with FD in 53 distal ICA aneurysm patients (M:F=8:45, mean age = 54.2 years). The location of aneurysms included cavernous (5), ophthalmic (37), posterior communicating artery (8), and anterior choroidal artery (3). The average time to follow-up was 409 days. The FD devices that were used include Pipeline Embolic Device (n=27), Surpass (n=25), and Fred (n=1). There were 2 patients (2/53, 3.77%) who had anterior choroidal artery occlusions. However, both patients were asymptomatic. 18 (34%) of the patients had subtherapeutic ADP inhibition based on TEG (defined as <70% inhibition at our institution). These patients had clopidogrel switched, mostly to prasugrel.

Conclusion Occlusion of the anterior choroidal artery after FD coverage rarely occurs and the incidence of clinically symptomatic occlusion appears to be rarer. Complications may have been alleviated with personalized dual anti-platelet therapy using TEG results.

Disclosures R. Holland: None. D. Khatri: None. R. Zampolin: None. N. Haranhalli: None. D. Altschul: None. A. Brook: None. S. Lee: None.