oval etc in a presently preferred embodiment strands 32 42 are comprised of nickel titanium alloy suitable nickel titanium alloys are commercially available from memry technologies brookfield connecticut tini alloy company san leandro calif and shape memory applications sunnyvale calif those with skill in the art will appreciate that strands 32 42 may be comprised of other metallic or non metallic materials without departing from the spirit or scope of the present invention examples of metallic materials which may be suitable for some applications include stainless steel and titanium suitable non metallic materials may be selected from the following list which is not exhaustive poly l lactide plla poly d l lactide pla polyglycolide pga poly l lactide co d l lactide plla pla poly l lactide co glycolide plla pga poly d l lactide co glycolide pla pga poly glycolide co trimethylene carbonate pga ptmc polyethylene oxide peo polydioxanone pds polycaprolactone pcl polyhydroxylbutyrate phbt poly phosphazene polyd l lactide co caprolactone pla pcl poly glycolide co caprolactone pga pcl polyanhydrides pan poly ortho esters poly phoshate ester poly amino acid poly hydroxy butyrate polyacrylate polyacrylamid poly hydroxyethyl methacrylate polyurethane polysiloxane and their copolymers 0036 fig2 is a plan view of a removal catheter 90 disposed in blood vessel lumen 22 proximate thrombus filter 20 removal catheter 90 includes an outer tubular member 100 having a lumen 102 a distal end 104 and a proximal end 106 not shown in the embodiment of fig2 an inner tubular member 200 is disposed within lumen 102 of outer tubular member 100 inner tubular member 200 includes a lumen 202 a distal end 204 and a proximal end 206 not.