Methods of forming a structure for treating a vessel include providing a mandrel and braiding a plurality of filaments around the mandrel. The mandrel may include a strand having a longitudinal axis and a plurality of balls coupled to the strand along the longitudinal axis. Pairs of the plurality of balls may be spaced along the longitudinal axis. Braiding the plurality of filaments around the mandrel may include, during braiding, forming a plurality of bulbs around the plurality of balls and forming necks between pairs of the plurality of balls. The methods may include, after braiding the plurality of filaments, heat treating (e.g., shape setting) the plurality of filaments on the mandrel. Portions of the braided plurality of filaments may be secured to the mandrel, for example using bangles, wire, and/or adhesive.