CASE REPORT: We report a left A1 aneurysm with a wide neck and small sac (3 × 1.8 mm). In order to treat the lesion, a flow diverter (4 × 12?18 mm, FRED, Microvention) was placed from M1 to the proximal end of the paraophthalmic internal carotid artery, without directly covering the neck of the aneurysm. No procedural bleeding occurred. During stent deployment, abciximab was infused. A day after the procedure, double antiplatelet therapy was initiated for 1 month, followed by single antiplatelet therapy for another 3 months.

Due to the aneurysm morphology, we opted for a competitive flow diversion, covering the parent artery origin and leaving the A1A neck uncovered. A decreased flow into the aneurysmal parent artery gradually promoted aneurysm sac thrombosis. Both digital subtraction angiography at a 12-month follow-up and computed tomography angiography 24-month follow-up confirmed the regular patency of the stent and resolution of the aneurysm. In addition, the competitive modulation of flow in the ipsilateral anterior cerebral artery results in the narrowing of the vessel.

CONCLUSION: A1 aneurysm endovascular treatment is often challenging. Coiling or assisted coiling is the most frequently employed. Although flow diverter stent (FDS) is a consolidated technique for treating ruptured intracranial blister-like and dissecting aneurysms, its role in treating intracranial saccular ruptured aneurysms has to be elucidated. However, more number of case studies is needed to confirm the efficacy and safety of an FDS in treating ruptured A1 aneurysms. Keywords : Endovascular, Flow diverter, A1 Aneurysm, Ruptured aneurysm