Filter and method for trapping emboli during endovascular procedures

• US 5,941,896 A
• Filed: 12/16/1997
• Issued: 08/24/1999
• Est. Priority Date: 09/08/1997
• Status: Expired due to Term

• Current Assignee: Montefiore Hospital and Medical Center Incorporated
• Original Assignee: Montefiore Hospital and Medical Center Incorporated
• Inventors: Kerr, Andrew
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Bui, Vy Q.
• Application Number:
  US08/991,469
• Time in Patent Office: 616 Days
• Field of Search: 606/159, 606/200, 606/192, 606/106, 606/110, 606/113, 606/114, 606/127, 606/128, 606/151
• 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 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0067 conical

Abstract

A filter and method for trapping emboli during endovascular procedures are provided. In one embodiment of the invention, the filter is formed from a bent, flexible guidewire shaped to define a frame and a porous filtering material mounted to portions thereof. In a collapsed state, the filter can readily pass through the lumen of a catheter and into the bloodstream of a patient. Upon completion of an endovascular procedure, the filter is collapsed and retracted into the catheter. In alternative embodiments of the invention, porous filtering material is mounted to external portions of a catheter, and a control guidewire is provided to selectively expand the filter between open and closed states.

Claims

1. A filter for trapping emboli during endovascular procedures in a blood vessel, said filter comprising:

a flexible guidewire having a first end, a second and and an intermediate portion extending therebetween, said intermediate portion including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection, said first segment defining a loop, said second segment extending from and through said loop; and

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected along a first length of said second segment, wherein said first length of said second segment is disposed in a plane transverse to other portions of said second segment.

2. A filter as in claim 1, wherein said first length of said second segment being formed to define a generally circular shape extending from and into said loop.

3. A filter as in claim 2, wherein said second segment being formed with a generally straight second length extending from said first length of said second segment, said second segment being formed with a generally straight third length extending from said second length and through said generally circular shape defined by said first length of said second segment, said second and said third lengths defining an acute angle therebetween.

4. A blood filtering system for trapping emboli in a blood vessel during endovascular treatment, said system comprising:

a tubular catheter having a distal end for insertion into the blood vessel to be treated, said catheter defining a lumen along the entire length thereof;

a guidewire slidably disposed in said lumen of said catheter, said guidewire having a first end, a second end and an intermediate portion extending therebetween, said intermediate portion including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection, said first segment defining a loop, said second segment extending from and through said loop, said second segment extending in a direction away from said distal end of said catheter; and

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected along a length of said second segment, wherein said guidewire and said filtering material collectively form a collapsible filter, said filter being reversibly collapsible between a relaxed state and a collapsed state, wherein, in said relaxed state, said filter being opened with a length of said second segment shaped and dimensioned for pressing engagement with the blood vessel, and, wherein, in said collapsed state, said filter being closed and capable of sliding passage through said lumen of said catheter.

5. A system for endovascular treatment of a blood vessel, said system comprising:

a tubular catheter having a distal end for insertion into the blood vessel to be treated, said catheter defining a lumen along the entire length thereof;

a guidewire slidably disposed in said lumen of said catheter, said guidewire having a first end, a second end and an intermediate portion extending therebetween, said intermediate portion including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection, said first segment defining a loop, said second segment extending from and through said loop, said second segment extending in a direction away from said distal end of said catheter;

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected along a length of said second segment, wherein said guidewire and said filtering material collectively form a collapsible filter, said filter being reversibly collapsible between a relaxed state and a collapsed state, wherein, in said relaxed state, said filter being opened with a length of said second segment shaped and dimensioned for pressing engagement with the blood vessel, and, wherein, in said collapsed state, said filter being closed and capable of sliding passage through said lumen of said catheter; and

an endovascular treatment device slidably disposed on said guidewire for endovascular treatment of the blood vessel.

6. A system as in claim 5, wherein said endovascular treatment device includes an angioplasty balloon.

7. A system as in claim 5, wherein said endovascular treatment device includes a stent.

8. A blood filtering system for trapping emboli in a blood vessel during endovascular treatment, said system comprising:

a tubular catheter having a proximal end and a distal end, said distal end for insertion into the blood vessel to be treated, said catheter being formed with a continuous cylindrical wall extending between said ends, said wall defining a lumen along the entire length of said catheter, wherein an aperture is formed through said wall in proximity to said distal end, said aperture defining a passage extending through said wall and in communication with said lumen;

a guidewire having a first end, a second end and an intermediate portion extending therebetween, said second end of said guidewire being located proximally the proximal end of said catheter, said intermediate portion of said guidewire including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection of said intermediate portion, said first segment defining a loop, said loop being disposed at a location external to said catheter, wherein said second segment extends continuously from said loop, through said loop, through said aperture, into said lumen, and to said second end of said guidewire; and

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected along a length of said second segment, said filtering material also being secured to a portion of said wall of said catheter.

9. A system as in claim 8, wherein said filtering material is secured to said wall of said catheter at locations intermediate said distal end of said catheter and said aperture.

10. A system as in claim 8, wherein said filtering material is secured to said wall of said catheter at locations intermediate said proximal end of said catheter and said aperture.

11. A system as in claim 8, wherein an inflatable angioplasty balloon is mounted to said wall of said catheter.

12. A filter for trapping emboli during endovascular procedures in a blood vessel, said filter comprising:

a flexible guidewire having a first end, a second end and an intermediate portion extending therebetween, said intermediate portion including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection, said first segment defining a loop, said second segment extending from and through said loop with a first length of said second segment being formed to define a generally circular shape extending from and into said loop; and

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected to said first length of said second segment, wherein said first length being dimensioned to be fully in pressing engagement with the blood vessel.

13. A filter for trapping emboli during endovascular procedures in a blood vessel, said filter comprising:

a flexible guidewire having a first end, a second end and an intermediate portion extending therebetween, said intermediate portion including a first segment, a second segment and a unitary connection therebetween, said first segment extending a predetermined distance from said first end, said first segment being bent with said first end being secured to said unitary connection, said first segment defining a loop, said second segment extending from and through said loop with a first length of said second segment being formed to define a generally circular shape extending from and into said loop, said second segment being formed with a generally straight second length extending from said first length of said second segment, said second segment being formed with a generally straight third length extending from said second length and through said generally circular shape defined by said first length of said second segment, said second and said third lengths defining an acute angle therebetween; and

a porous filtering material having interstices dimensioned to prevent passage therethrough of life-threatening emboli, said filtering material being slidably connected to said first length of said second segment, wherein said first length being dimensioned for pressing engagement with the blood vessel.