Vena cava filter with filament
A vena cava filter is described, having one or more frame members or an elongated member arranged in helical fashion. A plurality of filaments connect frame members or portions of the elongated member. The filaments may be made of suture material. Hooks may be placed on a free end of the filaments, along the length thereof, or on one or more frame members to engage the blood vessel wall and anchor the filter. A retrieval member may be positioned on the filter to facilitate withdrawal of the filter from the blood vessel.
1. A blood vessel filter comprising:
two or more generally arcuate frame members spaced apart and arranged along a longitudinal axis of the filter;
and
a plurality of filaments connecting the frame members; wherein the frame members have a circular configuration; and wherein each of the frame members comprises a first section that has at least one portion slidably disposed inside a second section in a first configuration of the filter, and wherein the at least one portion is slidably disposed outside the second section in a second configuration of the filter.
2. The filter of claim 1 wherein at least one of the frame members and filaments comprise suture material.
3. The filter of claim 1 wherein each of the filaments loop at least one time around each of the frame members along the longitudinal axis.
4. The filter of claim 1 wherein at least some of the filaments include a hook that engages a wall of a blood vessel.
5. The filter of claim 4 wherein the hooks lay on a free end of the filaments.
6. The filter of claim 1 wherein
each frame member has a first diameter and a second diameter,
and
at least the first diameter of successive members increases along the longitudinal axis.
7. The filter of claim 6 wherein each frame member comprises a continuous member.
8. The filter of claim 7 wherein the shape memory material is one of shape memory alloy, shape memory polymer, super elastic shape memory metal alloy, linear elastic shape memory alloy, or combinations of these.
9. The filter of claim 8 wherein the continuous member comprises a shape memory material.
10. The filter of claim 8 wherein at least one of the frame members comprises a bioabsorbable material.
11. The filter of claim 10 wherein at least one of the frame members includes at least one hook.
12. The filter of claim 11 wherein the at least one hook comprises a linear portion connected to an arcuate portion that terminates in a point, the arcuate member having a cross-sectional area smaller than the cross-sectional area of the linear portion.
13. The blood vessel filter of claim 1 further comprising a hook or barb positioned on one or more of the filaments.
14. The blood vessel filter of claim 13 wherein the first configuration defines a first outer perimeter smaller than a second outer perimeter of the second configuration.
15. The blood vessel filter of claim 14 wherein one of the first portion and second portion comprises a limit member to prevent separation of the first section from the second section.
16. The blood vessel filter of claim 14 wherein one of the first portion and second portion comprises a lock to prevent further adjustment of the first section relative to the second section.
17. The blood vessel filter of claim 15 wherein at least one of the frame members comprises a bioabsorbable material.
18. The blood vessel filter of claim 15 further comprising at least one hook disposed on at least one of the frame members.