Objective: The risk of rebleeding is reported higher in ruptured cerebral aneurysms treated with endovascular coiling than in patients treated with surgical clipping. In this study, we evaluate the time and risk factors of rebleeding after coil embolization of ruptured cerebral aneurysms.
Methods: From April 2001 to August 2014, we performed coil embolization on 288 ruptured cerebral aneurysms. We evaluated the frequency, time and risk factors of rebleeding in terms of patient background, location, size, ratio of dome to neck, volume embolization ratio (VER), and remnant flow into aneurysms immediately after embolization.
Results: We suffered 6 rebleedings (2.1%) within 24 hours after the initial coil embolization (early-rebleeding), and 6 rebleedings (2.1%) within 1 year after the embolization in the patients who we could follow up, and 3 rebleedings (late-rebleeding) 1 year later. All of early-rebleeding occurred within 12 hours. 5 of 6 rebleedings within 1 year after the embolization occurred within 3 months from 30 days after, and one patient who was administered warfarin suffered rebleeding 13 days after the treatment. Antihypertensive therapy after the embolization tended to prevent early-rebleeding (p=0.092), but we revealed no significant factor related to early-rebleeding. We demonstrated significant differences between ratio of dome to neck and rebleeding within 1 year after (p=0.035), and between angiographic result and rebleeding within 1 year after (p=0.001).
Conclusions: Most of rebleeding after coil embolization occurred within 12 hours or within 3 months from 30 days after the treatment. We recommend antihypertensive therapy and the angiogram 1month after the coil embolization at our institution.