An implantable medical device, such as a vena cave filter 10 has first and second ends 14, 16. At one end 14 there is provided a material capture element 18 which has a generally closed conical deployed shape and a narrow end 20 disposed at or proximate the first end 14 of the device. The material capture element 18 includes a wide end 22 which faces the second end 16 of the device, the material capture element 18 having a zone 32 of wider radial dimension which provides a first vessel contact site. A plurality of wire tethers 40 are coupled to the material capture element 18 at its wide end and extend to the second end 16 of the device. The wire tethers 40 are provided with portions 50 of wider radial dimension which provide a second vessel contact site. The first and second contact sites 32, 50 are longitudinally spaced from one another. First and second retrieval elements 26 are disposed at the first and second ends 14, 16.
