This invention is a device and method for reducing blood flow into an aneurysm, especially a cerebral aneurysm, in order to promote therapeutic embolization of the aneurysm. The device comprises: at least one core member that is inserted into the aneurysm; and at least one longitudinal flexible member that is wound repeatedly around the core member within the aneurysm. The longitudinal flexible member is wound around the core member until the rotational accumulation of the flexible member reduces blood flow into the aneurysm and promotes therapeutic embolization of the aneurysm.