Rebleeding from a vertebral artery dissecting aneurysm after endovascular internal trapping: adverse effect of intrathecal urokinase injection or incomplete occlusion?-case report-.

A 67-year-old woman suffered rebleeding from a ruptured vertebral artery dissecting aneurysm after endovascular internal trapping. The dissecting aneurysm was initially successfully occluded with the affected vertebral artery using detachable coils. However, rebleeding from the aneurysm occurred on the next day. The rebleeding may have resulted from the thrombolytic effect of urokinase, which was injected intrathecally 3 hours before rebleeding occurred, or the relatively loose coil packing of the aneurysm. This case indicates the potential risk of intrathecal use of thrombolytic agents and the importance of complete tight coil packing of the whole dissected site in the treatment of ruptured vertebral artery dissecting aneurysms.