ABSTRACT NUMBER: ESOC2026A2002 FLOW DIVERSION FOR THROMBOSED MIDDLE CEREBRAL ARTERY BIFURCATION ANEURYSM PRESENTING WITH ISCHEMIC STROKE

Abstract Background and aims Middle cerebral artery (MCA) bifurcation aneurysms typically present incidentally on imaging or with subarachnoid hemorrhage and are often managed surgically due to their peripheral location and complex anatomy. Presentation with ischemic stroke is extremely rare, particularly when associated with intrasaccular thrombosis, which poses both thromboembolic and rupture risks. Methods A 68-year-old woman with a history of smoking presented with acute left MCA territory infarcts. Computed tomography angiography (CTA) demonstrated a left MCA bifurcation aneurysm with an atypical luminal contour, suggesting intrasaccular thrombus. Vessel wall magnetic resonance imaging (MRI) indicated aneurysm instability. In view of the risks of recurrent thromboembolism and rupture, endovascular flow diversion was performed across the aneurysm into the superior division under dual antiplatelet therapy. The procedure was well tolerated and yielded excellent angiographic results. Results Follow-up head CTA 48 hours post-procedure demonstrated stable device position with preserved superior division flow. The patient recovered without new deficits and was discharged on postoperative day 4 on dual antiplatelet therapy, transitioning to aspirin monotherapy after six months. At two-year follow-up, the patient remained clinically well. Conclusions The management of partially thrombosed MCA aneurysms presenting with ischemic stroke remains challenging and is not well defined. In this case, flow diversion addressed both thromboembolic and rupture risks safely. Broader data collection through multicenter registries may help clarify the natural history and optimal management of this rare presentation. Conflict of interest Archit Baskaran; Nothing to disclose Chibueze Agwu; Nothing to disclose Rami Z Morsi; Nothing to disclose Tareq Kass-Hout; Nothing to disclose Michael Hurley; Nothing to disclose