A vascular occlusion device for effectively occluding blood flow and pressure to a vascular defect while simultaneously not occluding blood flow and pressure to adjacent vasculature is provided. The vascular occlusion device can include a tubular member that has variable porosity regions along its length. The tubular member can be formed of a plurality of filaments that have different cross-sectional shapes along their length that are indexed to the variable porosity regions along the length of the tubular member.