A vaso-occlusion system for occluding an aneurysm includes a delivery catheter having a delivery lumen extending therethrough, a pusher member at least partially extending through the delivery lumen, and a vaso-occlusive device loaded within the delivery lumen, the vaso-occlusive device comprising an expandable braid formed out of a plurality of elongate braid filaments, the elongate braid elements having respective proximal end portions that are formed into a flexible transition section having a proximal end portion attached to a distal end of the pusher member and/or to an elongate central member coupled to, and extending distally of, the pusher member.