Balloon catheter having dual markers and method

• US 5,779,731 A
• Filed: 12/20/1996
• Issued: 07/14/1998
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Leavitt, Ernest E.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US08/770,875
• Time in Patent Office: 571 Days
• Field of Search: 606/191, 606/192, 606/194, 606/195, 606/198, 606/200, 604/95-101, 623/1, 623/12
• US Class Current: 606/194
• CPC Class Codes: A61M 2025/1079 having radio-opaque markers in the region of the balloon
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/1027 Making of balloon catheters

Abstract

An intravascular balloon catheter has a balloon near the distal end of a catheter shaft and a pair of radiopaque markers positioned within the balloon interior. The distal marker is disposed on an inner shaft member, and the proximal marker is disposed at the distal end of an outer shaft member. The markers may be positioned to indicate under fluoroscopy the position and working length of the balloon.

Claims

1. An intravascular balloon catheter for treating a portion of the body of a patient, comprising:

a flexible catheter shaft, at least a distal portion of the catheter shaft having an inner shaft member coaxially surrounded by an outer shaft member, an inflation lumen being defined by an annular space between said inner and outer shaft members;

a flexible balloon disposed near a distal end of the catheter shaft, the balloon having a working portion with a constant cross-sectional area, a proximal end of the balloon being sealed to the outer shaft member, and a distal end of the balloon being sealed to the inner shaft member, whereby the inflation lumen is in fluid communication with the interior of the balloon; and

first and second radiopaque markers disposed within the interior of the balloon, the first marker being affixed to the inner shaft member, and the second marker being affixed to the outer shaft member, said first and second markers being positioned at a distal and proximal end of the balloon working portion, respectively, whereby the first and second markers indicate under fluoroscopy the position of the balloon working portion within the body of the patient.

2. The intravascular balloon catheter as set forth in claim 1, wherein the balloon working portion has a cylindrical shape.

3. The intravascular balloon catheter as set forth in claim 2, the balloon further comprising a proximal and distal frusto-conical tapering segment, and proximal and distal legs being sealed to the outer and inner shaft members, respectively, wherein each of the first and second markers are longitudinally positioned at a transition between the cylindrical working portion and the distal and proximal tapering segments, respectively.

4. The intravascular balloon catheter as set forth in claim 1, wherein the balloon is formed of at least two layers of different materials.

5. The intravascular balloon catheter as set forth in claim 1, further comprising a flexible fixed wire affixed to the inner shaft member and extending distally beyond the distal end of the inner shaft member.

6. The intravascular balloon catheter as set forth in claim 1, wherein the balloon is formed of a substantially inelastic material.

7. The intravascular balloon catheter as set forth in claim 1, wherein the inner shaft member defines a guidewire lumen adapted to slidingly receive a guidewire extending from a proximal guidewire port that is proximal of the balloon to a distal guidewire port that is distal to the balloon.

8. The intravascular balloon catheter as set forth in claim 7, wherein the proximal guidewire port is disposed between a proximal end of the catheter shaft and the balloon, thereby enabling a guidewire to traverse a path from the distal guidewire port through the guidewire lumen defined by the inner shaft member, through the proximal guidewire port, and extend proximally along the exterior of a proximal portion of the catheter shaft in a rapid exchange configuration.

9. The intravascular balloon catheter as set forth in claim 7, wherein said catheter shaft further comprises a proximal shaft portion defining a proximal inflation lumen and a proximal guidewire lumen, the proximal inflation lumen communicating with an inflation lumen defined by an annular space between the outer and inner shaft members, and the proximal guidewire lumen extending parallel to the proximal inflation lumen and communicating with the guidewire lumen.

10. The intravascular balloon catheter as set forth in claim 7, wherein said inner shaft member is formed of at least two layers of different materials, the innermost layer defining the guidewire lumen and being more lubricious to facilitate movement of a guidewire within the guidewire lumen.

11. The intravascular balloon catheter as set forth in claim 1, wherein inner and outer shaft members are each formed of plastic, and the first and second markers are formed of metal.

12. An intravascular balloon catheter for treating a portion of the body of a patient, comprising:

a flexible catheter shaft. at least a distal portion of the catheter shaft having an inner shaft member coaxially surrounded by an outer shaft member, an inflation lumen being defined by an annular space between said inner and outer shaft members;

a flexible balloon disposed near a distal end of the catheter shaft, a proximal end of the balloon being sealed to the outer shaft member, and a distal end of the balloon being sealed to the inner shaft member, whereby the inflation lumen is in fluid communication with the interior of the balloon; and

first and second radiopaque markers disposed within the interior of the balloon, the first marker being affixed to the inner shaft member, and the second marker being affixed to the outer shaft member, whereby the first and second markers indicate under fluoroscopy the position of the balloon within the body of the patient, wherein the second marker is formed by a plastic ring containing a radiopaque agent and affixed to a distal end of said outer shaft member.

13. The intravascular balloon catheter as set forth in claim 12, wherein a percentage concentration of said radiopaque agent is predetermined, such that said first and second markers have equal fluoroscopic brightness.

14. The intravascular balloon catheter as set forth in claim 12, wherein the second marker has the same outer diameter as said outer shaft member.

15. An intravascular balloon catheter, comprising:

a first tube of flexible plastic defining a guidewire lumen, said first tube being formed of an outer plastic layer and an inner plastic layer, the plastic materials of said outer and inner plastic layers being different and bonded to each other, said guidewire lumen being adapted to slidingly receive a guidewire, said inner plastic layer exhibiting a more lubricious surface than said outer plastic layer;

a second flexible plastic tube surrounding said first tube and defining an inflation lumen between the outer surface of the first tube and the inner surface of the second tube;

a flexible balloon having a distal end coupled to said first tube and a proximal end coupled to said second tube, such that the interior volume of the balloon is in fluid communication with said inflation lumen; and

first and second radiopaque markers affixed to the first and second tube, respectively.

16. The intravascular balloon catheter as set forth in claim 15, in which the material of the outer plastic layer has greater stiffness than the material of the inner plastic layer.

17. The intravascular balloon catheter as set forth in claim 15, in which the material of said outer plastic layer is selected from the group consisting of nylon, polyurethane, and polyester.

18. The intravascular balloon catheter as set forth in claim 15, wherein the balloon defines a working length, said first and second markers being positioned at a distal and proximal end of the working length, respectively.

19. The intravascular balloon catheter as set forth in claim 15, wherein the balloon is formed of a substantially inelastic material.

20. The intravascular balloon catheter as set forth in claim 15, further comprising a distal guidewire port that is distal to the balloon and a proximal guidewire port that is between the balloon and a proximal end of the second tube, thereby enabling a guidewire to traverse a path from the distal guidewire port through the guidewire lumen, through the proximal guidewire port, and extend proximally along the exterior of a proximal portion of the catheter shaft in a rapid exchange configuration.

21. The intravascular balloon catheter as set forth in claim 20, wherein the second marker has the same outer diameter as said second shaft member.

22. The intravascular balloon catheter as set forth in claim 15, wherein the second marker is formed by a plastic ring containing a radiopaque agent and affixed to a distal end of said second shaft member.

23. The intravascular balloon catheter as set forth in claim 15, wherein inner and outer shaft members are each formed of plastic, and the first and second markers are formed of metal.

24. An intravascular balloon catheter for expanding a stent within the body of a patient, comprising:

a flexible catheter shaft, at least a distal portion of the catheter shaft having an inner shaft member coaxially surrounded by an outer shaft member;

a flexible balloon disposed near a distal end of the catheter shaft, a proximal end of the balloon being sealed to the outer shaft member, and a distal end of the balloon being sealed to the inner shaft member;

first and second radiopaque markers disposed within the interior of the balloon, the first marker being affixed to the inner shaft member, and the second marker being affixed to a distal end of the outer shaft member, an outer diameter of the second inner marker being larger than an outer diameter of the outer shaft member, thereby forming an annular shelf;

a stent assembled in a crimped configuration around the balloon in an uninflated state, whereby the balloon is adapted to inflate and expand the stent within the desired site, said annular shelf engaging a proximal end of the stent to resist proximal motion of the stent relative to the catheter shaft as the balloon catheter is advanced within the body of the patient.

25. The intravascular balloon catheter as set forth in claim 24, wherein the balloon defines a working length, said first and second markers being positioned at a distal and proximal end of the working length, respectively.

26. The intravascular balloon catheter as set forth in claim 24, wherein the inner shaft member defines a guidewire lumen adapted to slidingly receive a guidewire extending from a proximal guidewire port that is proximal of the balloon to a distal guidewire port that is distal to the balloon.

27. The intravascular balloon catheter as set forth in claim 26, wherein the proximal guidewire port is disposed between a proximal end of the catheter shaft and the balloon, thereby enabling a guidewire to traverse a path from the distal guidewire port through the guidewire lumen defined by the inner shaft member, through the proximal guidewire port, and extend proximally along the exterior of a proximal portion of the catheter shaft in a rapid exchange configuration.

28. A method of making an intravascular balloon catheter for treating a portion of the body of a patient, comprising the steps of:

providing an outer and inner shaft member, the outer shaft member being a tube defining a lumen having an inner diameter that is large enough to accept the inner shaft member within said lumen;

affixing distal and proximal radiopaque markers to the inner and outer shaft members, respectively;

providing a flexible balloon having a central substantially cylindrical portion, and a proximal and distal tapering segment;

sealing a proximal end of the balloon to the outer shaft member, such that the proximal marker is longitudinally aligned with a proximal transition between the central portion and the proximal tapering segment;

inserting the inner shaft member within the lumen of the outer shaft member and longitudinally aligning the distal marker with a distal transition between the central portion and the distal tapering segment; and

sealing a distal end of the balloon to the inner shaft member while the distal marker and the distal transition are so aligned.

29. The method of claim 28, further comprising the additional step of sealing the proximal ends of the inner and outer shaft members, to resist relative movement thereof.

30. The method of claim 28, further comprising the additional step of forming the proximal marker of a plastic formulation having a radiopaque agent.

31. The method of claim 28, wherein said step of providing the inner shaft member further comprises coextruding the inner shaft member into a tube defining a lubricious guidewire lumen.