LOOP THROMBECTOMY DEVICE

• US 20100211087A1
• Filed: 02/17/2009
• Published: 08/19/2010
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Osborne, Thomas A.
• Granted Patent: US 8,361,095 B2
• Time in Patent Office: Days
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320708 Curettes, e.g. hollow scraping instruments
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 2017/320716 comprising means for preventing embolism by dislodged material
• CPC Class Codes: A61B 2017/320733 with a flexible cutting or scraping element, e.g. with a whip-like distal filament member

Abstract

A thrombectomy device may include an elongate torsion member having a proximal end and a distal end, and a plurality of helically arranged engagement members disposed at a distal portion of the elongate torsion member. Preferably, at least a portion of the engagement members has a rounded, atraumatic shape. The engagement members have a collapsed state where the engagement members are compressed toward the elongate torsion member, and an expanded state where the engagement members are expanded radially outward. Preferably, the engagement members are attached to and extends radially outward from the elongate torsion member at a different longitudinal point such that the engagement members are spaced longitudinally and circumferentially from each other when in the expanded state. When the thrombectomy device is deployed in a body lumen or cavity, the engagement members expands out to contact a wall of the body lumen or cavity.

Claims

1. A medical device for removing a thrombus, the device comprising:

an elongate torsion member having a proximal end and a distal end; and

a plurality of helically arranged engagement members disposed at a distal portion of said elongate torsion member, said engagement members having a collapsed state wherein said engagement members are compressed toward said elongate torsion member, and an expanded state wherein said engagement members are expanded radially outward,

wherein said engagement members are attached to and extend radially outward from said elongate torsion member at different longitudinal points along said elongate torsion member such that said engagement members are spaced longitudinally and circumferentially from each other when in said expanded state, and wherein at least a portion of said engagement members has a rounded atraumatic shape.

2. The medical device of claim 1, wherein when deployed in a body lumen or cavity, said engagement members expand out such that said rounded atraumatic shape of said engagement members contacts a wall of said body lumen or cavity.

3. The medical device of claim 1, wherein an entirety of each of said engagement members consists of loop of wire that extends from said longitudinal point on said torsion member in a continuous manner, said loop of wire being made of a material having super-elastic characteristics.

4. The medical device of claim 3, wherein said elongate torsion member is a metallic shaft made from a flexible metallic material and said wire of each of said engagement members is permanently attached to said different longitudinal points.

5. The medical device of claim 3, wherein said elongate torsion member is a torque cable that is woven from a plurality of metallic wire strands, and wherein said wire forming said engagement members is a single continuous wire woven into said torque cable.

6. The medical device of claim 5, wherein said wire strands and said wire forming said engagement members are made of nitinol.

7. The medical device of claim 5, further comprising a torque shaft fixedly attached to said proximal end of said elongate torsion member.

8. The medical device of claim 7, further comprising a handle that engages said torque shaft such that when said handle is rotated said engagement members are also rotated.

9. The medical device of claim 1, wherein a distal tip of said torsion member has a blunt atraumatic shape.

10. The medical device of claim 7, further comprising an inner sheath disposed around said elongate torsion member and having a diameter that is less than an outer diameter of said helical arrangement of engagement members in said expanded state, said inner sheath comprising a spring member disposed at a distal end thereof, said spring member having a compressed configuration in which said spring member has a diameter substantially equal to said diameter of said inner sheath, and an expanded configuration in which at least a portion of said spring member has a diameter that is larger than said diameter of said inner sheath.

11. The medical device of claim 10, wherein said spring member has a proximal end that is restrained and a distal end that is unrestrained in said expanded state, such that said spring member has a cone like shape when expanded.

12. The medical device of claim 11, wherein a distal end of said inner sheath comprises pleats that are folded when said spring member is in said compressed configuration, and that are unfolded when said spring member is in said expanded configuration.

13. The medical device of claim 11, wherein at least a distal portion of said inner sheath is made of an elastic polymer that is coupled to said spring member such that said elastic polymer stretches when said spring member moves from said compressed to said expanded configuration.

14. The medical device of claim 13, further comprising a substantially inelastic outer sheath disposed on an outer surface of said inner sheath and slidably movable thereupon, said outer sheath restraining said spring member in said compressed configuration.

15. A medical device for removing a thrombus, the device comprising:

1) a torque cable that is woven from a plurality of metallic wire strands, said torque cable having a proximal end and a distal end, said distal end having a blunt atraumatic shape;

2) a plurality of helically arranged engagement members disposed at a distal portion of said torque cable, said members having a collapsed state wherein said engagement members are compressed radially inward, and an expanded state wherein said engagement members are expanded radially outward,

wherein each of said engagement members is a loop of wire extending from said torsion member in a continuous manner that is woven into said torque cable such that each engagement member extends radially outward from said torque cable at a different longitudinal point along said torque cable and said engagement members are spaced longitudinally and circumferentially from each other when in said expanded state, and

3) an inner sheath disposed around said torque cable and having a diameter that is less than a diameter of said helical arrangement of said engagement members in said expanded state, said inner sheath comprising a spring member disposed at a distal end thereof, said spring member having a compressed configuration in which said spring member has a diameter substantially equal to an inner diameter of said inner sheath, and an expanded configuration in which at least a portion of said spring member has a diameter that is larger than said diameter of said inner sheath,

wherein said spring member has a proximal end that is restrained and a distal end that is unrestrained in said expanded state, such that said spring member has a cone like shape when expanded.

16. A method of removing a thrombosis, said method comprising the steps of:

1) providing a thrombectomy device comprising;

a) an elongate torsion member having a proximal end and a distal end; and

b) a plurality of helically arranged engagement members disposed at a distal portion of said elongate torsion member, said members having a collapsed state wherein said engagement members are compressed toward said elongate torsion member, and an expanded state wherein said engagement members are expanded radially outward,

wherein said engagement members are attached to and extend radially outward from said elongate torsion member at different longitudinal points along said elongate torsion member such that said engagement members are spaced longitudinally and circumferentially from each other when in said expanded state, and wherein at least a portion of each engagement member has a rounded atraumatic shape;

2) introducing said thrombectomy device percutaneously into a body lumen or cavity proximal of a thrombosis;

3) expanding said thrombectomy device such that said plurality of engagement members are in said expanded state and at least a portion thereof contacts a wall of said body lumen or cavity;

4) rotatably advancing said thrombectomy device toward said thrombus such that said rounded atraumatic shape of said engagement members translates longitudinally along said wall in a corkscrew shaped path; and

5) twistingly engaging said thrombus with said plurality of helically arranged engagement members as said thrombectomy device is rotatably advanced, such that said thrombus is captured within said helical arrangement of engagement members.

17. The method of claim 16, wherein said thrombectomy device further comprises:

an inner sheath disposed around said elongate torsion member, said inner sheath comprising a compressed spring member disposed at a distal end thereof, said spring member having a compressed configuration in which said spring member has a diameter substantially equal to an inner diameter of said inner sheath, and an expanded configuration in which at least a portion of said spring member has a diameter that is larger than said diameter of said inner sheath.

18. The method of claim 17, further comprising:

expanding said spring member, thereby causing said distal end of said inner sheath to radially expand; and

retracting said thrombectomy device including said captured thrombus into said inner sheath through said expanded distal end.

19. The method of claim 18, wherein said thrombectomy device is linearly withdrawn into said inner sheath.

20. The method of claim 18, wherein said thrombectomy device is rotatably withdrawn into said inner sheath.