Real-World Endovascular Management of Symptomatic Intracranial Atherosclerotic Disease in Japan from the Acute to the Chronic Stage: A Narrative Review.

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke in Japan. The clinical manifestations of ICAD are heterogeneous, ranging from transient ischemic attacks caused by thromboembolism to progressive stroke related to severe atherosclerotic stenosis and acute, devastating stroke resulting from ICAD-related large vessel occlusion (LVO). Initial management strategies are also heterogeneous in the acute stage, ranging from aggressive medical management (AMM) as a primary strategy for nonocclusive ICAD to emergent endovascular treatment for ICAD-related LVO. Despite the wide variation in initial management approaches, a high incidence of stroke recurrence remains a distinctive feature of ICAD with high-grade stenosis. The risk of recurrent stroke in ICAD has been estimated to be approximately 10% after successful endovascular recanalization and 12%-15% after AMM. Recently, a randomized trial demonstrated that the addition of balloon angioplasty beyond the subacute stage significantly reduces the risk of stroke recurrence compared with AMM alone in clinically stabilized patients with symptomatic intracranial stenosis of 70%-99%. ICAD requires long-term management, spanning the acute, subacute, and chronic stages. The contemporary clinical environment in Japan is characterized by the unavailability of glycoprotein IIb/IIIa inhibitors and the limited selection of endovascular devices approved for domestic use. In this narrative review, current clinical practice is discussed in the context of the Japanese healthcare environment, with reference to illustrative real-world clinical cases. This review highlights practical treatment strategies and considerations for long-term management of ICAD in real-world clinical settings in Japan.