Perioperative Antiplatelet Therapy in the New Flow Diversion Era

Flow diverter (FD) technology has provided a new concept for the treatment of intracranial aneurysms: reconstruction of the parent artery by covering the neck with a braided mesh stent. It has enabled us to treat not only saccular aneurysms but also complex aneurysms that were previously considered difficult or impossible to treat. Despite its clinical impact, FD remains associated with thromboembolic and hemorrhagic complications, both of which are closely related to perioperative antiplatelet therapy. Dual antiplatelet therapy (DAPT), consisting of aspirin combined with a P2Y12 inhibitor, has traditionally been adopted as the standard strategy to reduce thromboembolic risk. However, the optimal regimen remains poorly defined, and substantial variability exists in clinical practice. Recent evidence suggests that the risk of thromboembolism is highest in the early perioperative period, while prolonged antiplatelet therapy may expose patients to unnecessary bleeding risks without clear additional benefits. In parallel, advances in platelet function testing, the availability of potent P2Y12 inhibitors, and the development of surface-modified FD devices are prompting reconsideration of the conventional paradigm of prolonged DAPT. This review provides a comprehensive synthesis of current evidence on perioperative antiplatelet therapy in the context of flow diversion and proposes a contemporary framework that emphasizes temporal risk stratification and individualized treatment strategies.