Percutaneous anti-migration vena cava filter

• US 5,242,462 A
• Filed: 10/17/1991
• Issued: 09/07/1993
• Est. Priority Date: 09/07/1989
• Status: Expired due to Term

• Current Assignee: Lifescreen Sciences LLC (Acacia Research Corporation)
• Original Assignee: Boston Scientific Corporation
• Inventors: Kordis, Thomas F., Weinreich, Michael, Savin, Michael A., Sahatjian, Ronald A., El-Nounou, Fozan O.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): LEWIS, WILLIAM W
• Application Number:
  US07/777,977
• Time in Patent Office: 691 Days
• Field of Search: 606/195, 606/198, 606/200, 128/899, 210/448, 623/1, 623/12
• US Class Current: 606/200
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/8486 provided on at least one of the ends
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0067 conical

Abstract

A filter device positionable within a blood vessel for trapping blood clots in that vessel, the filter device comprising a head with a plurality of divergent legs each secured at its proximal end, to the head, each leg having a hook arranged at its distal end.

Each leg has a radially outwardly directed radius of curvature to create a conical configuration to the filter assembly, while distributing the stress concentration along the length of the bend, so that the elastic limit of the material, stainless steel in this embodiment, is not exceeded, and which permits compact delivery of the filter, and adequate radially directed force to permit slight hook penetration of a vessel wall.

Claims

1. A filter device positionable within a blood vessel, for trapping blood clots, comprising:

an apical head;

a plurality of divergent legs each secured at one of its ends to said head and each having securement means on its distal end with respect to said head;

each of said legs having a first outwardly directed curvature immediately distally adjacent said head, said first curvature in each of said legs allowing insertion of the filter into a small diameter carrier, said first outwardly directed curvature extending in each of said legs, through an arc of about 0.5 inches;

each of said legs having a second outwardly directed curvature in the distalmost portion thereof to provide a slight outwardly directed flare therein while said filter is borne in a carrier, to reduce the possibility of entanglement of the hooks.

2. A filter device as recited in claim 1, wherein said first outwardly directed curvature in each of said legs has a radius of curvature of about 1.4 inches.

3. A filter device as recited in claim 1, wherein said second outwardly directed bend in each of said legs extends through an arc of about 1 inch.

4. A filter device as recited in claim 3, wherein said second outwardly directed bend in each of said legs has a radius of curvature of about 8 inches.

5. A filter device for positioning within a blood vessel, to be utilized for entrapment of blood clots, said filter comprising;

an apical head;

a plurality of divergent legs each secured at one of its ends to said head and each having securement means on its distal end with respect to said head;

each of said legs having a first outwardly directed curvature therein, closely distally adjacent said head, so that the distal remainder of said legs define a generically conical configuration and also to minimize the strain in said legs permitting the filter to be stored in a collapsed state, yet have enough elastic recoil to permit it to expand toward its uncollapsed configuration to allow penetration of a vessel wall upon ejection of the filter therein;

said first outwardly directed bend extending in said legs through an arc of about 0.5 inches;

said first outwardly directed bend having a radius of curvature of about 1.4 inches;

said leg having a second outwardly directed curvature extending through an arc of about 1 inch.

6. A filter device as recited in claim 5, wherein said second outwardly directed curvature has a radius of curvature of about 8 inches.

7. A filter device positionable within a blood vessel for trapping blood clots, comprising:

a apical head;

a plurality of divergent legs each secured at one of its ends to said head and each having securement means on its distal end with respect to said head, said head and said legs having a longitudinally directed center line therewithin;

said head having a cylindrical bore in axial alignment with said center line of said filter adaptable to receive a guidewire for alignment and guidance of said filter upon ejection thereof into a vessel;

said cylindrical bore having a counterbore disposed in each longitudinal end thereof to facilitate emplacement of a guidewire therewith;

said divergent legs having a first radially outwardly directed radius of curvature of about 1.4 inches over an arc of about 0.5 inches in length immediately adjacent said head to permit establishment of a conical geometric configuration to the plurality of legs extending from said apical head.

8. A filter device as recited in claim 7, wherein each of said divergent legs has a second radially outwardly directed radius of curvature of about 8 inches over an arc of about 1 inch in length at the distal end of said each leg, to create a slight outward flare therein, minimizing entanglement thereof.

9. A filter device as recited in claim 7, wherein said divergent legs are made from stainless steel.