A system comprises an implantable support structure and (a) a unit configured for percutaneous delivery of said support structure in an elongated state inside a catheter to a target site； (b) a unit configured for retraction of said catheter relative to said support structure such that a first portion of said support structure is expandable at the target site； (c) a unit configured for advancement of a second portion of said support structure into said first portion such that a first fold is created between said first and second portions； (d) a unit configured for retraction of said catheter relative to said second portion until said second portion expands against an interior of said first portion, thereby creating a multi-layered support structure； and (e) a unit configured for release of the support structure and removal of said catheter from the target site.
