An occlusion device and a method for occluding an opening in a body tissue with the occlusion device are provided. The occlusion device comprises a middle portion, a distal portion, and a proximal portion. The middle portion may be formed of non-woven wires and twisted about the longitudinal axis. The distal portion and the proximal portion may be comprised of a shape memory material. The occlusion device may be shape set to establish a preset configuration, and thus may be deformable to fit in and occlude the opening in the body tissue.