Medical device for occluding an opening in a vascular system formed from a metal fabric having a plurality of metal strands. Clamps are affixed to the ends of the metal strands. Stretching the device reduces the cross-sectional dimension of the device for deployment through a catheter. When the constraining force is removed, the device returns to its pre-set shape. A method of forming a device from a metal fabric formed of a plurality of strands includes the steps of conforming the fabric to a surface, defining an expanded configuration of the device in which the relative position of the strands is re-orientated. These strands are set in the re-orientated positions before removal of the moulding element.
