A vessel filter comprising a first distal region terminating at a first end and a second proximal region terminating at a second end of the filter and movable between a collapsed position for delivery to the vessel and an expanded position for placement within the vessel. The first region has a filter portion having a converging region to direct particles toward the center of the filter. The second region is flared in the expanded position to have a transverse dimension increasing toward a second end portion opposite the filter portion and includes a vessel engaging portion at the second end portion. The first region has a retrieval hook and a spacer forming a looped region extending radially from the first region.
1. A vessel filter comprising a first cranial region terminating at a first end and a second caudal region terminating at a second end of the filter, the filter movable between a collapsed position for delivery to a vessel and an expanded position for placement within the vessel, the first cranial region having a filter portion having a converging region to direct particles toward a center of the filter, the converging region converging into a tubular portion, the second caudal region forming a mounting region and being flared in the expanded position to have a transverse dimension increasing toward a second end portion opposite the filter portion, the second caudal region including a vessel engaging portion at the second end portion, the first region having a retrieval hook and a spacer, wherein in the collapsed position the spacer extends from the tubular portion in a cranial direction cranially beyond the retrieval hook and along an axis substantially parallel to a longitudinal axis of the filter in the collapsed position of the filter, the spacer being a single elongated strut and in the expanded position forms a loop extending radially from the tubular portion, wherein the spacer in the expanded position has a maximum transverse dimension less than a maximum transverse dimension of the filter in the expanded position.
2. The vessel filter of claim 1 , wherein the spacer is formed from an elongated cutout in the tubular portion of the filter.
3. The vessel filter of claim 2 , wherein the spacer extends from the cutout at a curved transition region.
4. The vessel filter of claim 1 , wherein the loop is an open loop.
5. The vessel filter of claim 1 , wherein the spacer in the collapsed position is radially spaced from a central longitudinal axis of the filter.
6. The vessel filter of claim 5 , wherein the spacer is formed from an elongated cutout extending to a cranial edge of the tubular portion.
7. The vessel filter of claim 1 , wherein the retrieval hook has a cutout exposing an internal annular surface.
8. The vessel filter of claim 1 , wherein the spacer is formed from an elongated cutout extending to a cranial edge of the tubular portion.
9. The vessel filter of claim 8 , wherein in the expanded position the loop is positioned caudal of a tip of the retrieval hook.
10. The vessel filter of claim 1 , wherein the spacer is formed from a tubular section in which a second spacer of another filter is formed.
11. The vessel filter of claim 1 , wherein in the expanded position the loop is positioned caudal of a tip of the retrieval hook.
12. A vessel filter comprising a first cranial region terminating at a first end and a second caudal region terminating at a second end of the filter, the filter movable between a collapsed position for delivery to a vessel and an expanded position for placement within the vessel, the first cranial region having a filter portion having a converging region to direct particles toward a center of the filter, the converging region converging into a tubular portion, the second caudal region forming a mounting region and being flared in the expanded position to have a transverse dimension increasing toward a second end portion opposite the filter portion, the second caudal region including a vessel engaging portion at the second end portion, the first region having a retrieval hook and a spacer, wherein in the collapsed position the spacer extends from the tubular portion in a cranial direction cranially beyond the retrieval hook and along an axis substantially parallel to a longitudinal axis of the filter in the collapsed position of the filter, the spacer being a single elongated strut and in the expanded position forms a loop extending radially from the tubular portion, wherein the spacer encircles the tubular portion.
13. A vessel filter comprising a first cranial region terminating at a first end and a second caudal region terminating at a second end of the filter, the filter movable between a collapsed position for delivery to a vessel and an expanded position for placement within the vessel, the first cranial region having a filter portion having a converging region to direct particles toward a center of the filter, the converging region converging into a tubular portion, the second caudal region forming a mounting region and being flared in the expanded position to have a transverse dimension increasing toward a second end portion opposite the filter portion, the second caudal region including a vessel engaging portion at the second end portion, the first region having a retrieval hook and a spacer, wherein in the collapsed position the spacer extends from the tubular portion in a cranial direction cranially beyond the retrieval hook and along an axis substantially parallel to a longitudinal axis of the filter in the collapsed position of the filter, the spacer being a single elongated strut and in the expanded position forms a loop extending radially from the tubular portion, wherein in the expanded position the loop is substantially perpendicular to the longitudinal axis of the filter so that the longitudinal axis passes through an opening in the loop.
14. The vessel filter of claim 13 , wherein the spacer in the expanded position has a transverse dimension less than a transverse dimension of the filter in the expanded position.
15. The vessel filter of claim 13 , wherein the spacer extends upwardly from a cranial end and continues downwardly to wrap around the tubular portion.
16. The vessel filter of claim 15 , wherein the spacer continues downwardly to wrap around the tubular portion and loop less than 360 degrees.