1. Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan
2. Department of Neurosurgery, Saiseikai Matsusaka General Hospital, Matsusaka, Mie, Japan
3. Department of Innovative Neuro-Intervention Radiology, Mie University Graduate School of Medicine, Tsu, Mie, Japan
4. Center for Vessels and Heart, Mie University Hospital, Tsu, Mie, Japan