The secondary belt support member 454 may be made from alloys such as nickel titanium, stainless steel, or polymeric materials such as polyimide and can have an outside transverse dimension ranging from about 0.01 inch to about 0.06 inch. [0173] A proximal primary belt 456 is shown in FIG. 26 disposed about and radially constraining the proximal self-expanding member 407 of the ipsilateral leg 404