Reinforced multiple lumen catheter

• US 5,221,255 A
• Filed: 10/16/1991
• Issued: 06/22/1993
• Est. Priority Date: 01/10/1990
• Status: Expired due to Term

• Current Assignee: Sudha S. Mahurkar Trust
• Original Assignee: Sakharam D. Mahurkar, Smriti S. Mahurkar
• Inventors: Mahurkar, Smriti S., Mahurkar, Sakharam D.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/776,873
• Time in Patent Office: 615 Days
• Field of Search: 604/43-45, 604/264, 604/280, 604/281, 604/282
• US Class Current: 604/43
• CPC Class Codes: A61M 2025/0031 characterized by lumina for withdrawing or delivering, i.e. used for extracorporeal circuit treatment
• CPC Class Codes: A61M 2025/0037 characterized by lumina being arranged side-by-side
• CPC Class Codes: A61M 2025/004 characterized by lumina being arranged circumferentially
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0028 characterized by features relating to at least one lumen located at the proximal part of the catheter, e.g. alterations in lumen shape or valves catheter hubs A61M25/0097
• CPC Class Codes: A61M 25/0029 characterized by features relating to least one lumen located at the middle part of the catheter, e.g. slots, flaps, valves, cuffs, apertures, notches, grooves or rapid exchange ports catheter shaft surface irregularities A61M2025/006
• CPC Class Codes: A61M 25/003 characterized by features relating to least one lumen located at the distal part of the catheter, e.g. filters, plugs or valves catheter tips A61M25/0067
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/0053 having a variable stiffness along the longitudinal axis, e.g. by varying the pitch of the coil or braid

Abstract

A dual-lumen catheter comprises an elongated cylindrical tube made of silicone and having an internal septum extending along the length thereof to form a pair of longitudinal lumens. A hollow conical tip is formed on the distal end of the tube with the outside surface of the conical tip merging smoothly with the outside surface of the tube, and the inside surface of the conical tip merging smoothly with the inside surface of one of the lumens.

The distal end of the other lumen is longitudinally spaced from the distal end of the tip. A reinforcing member is located inside the tube and extends along the length of the tube. The reinforcing member is made of a material which is substantially stiffer than the material of the tube so that the catheter can be advanced against a resistance by the applications of force to the proximal end of the catheter.

Claims

1. A dual-lumen hemodialysis catheter comprising:

an elongated cylindrical tube made of a uniformly soft, elastic material which is compatible with the human body, said tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other in the axial direction, and

a diametral reinforcing member extending along the length of said septum, and made of a material which is substantially stiffer than the material of said tube so that the catheter can be advanced longitudinally against a resistance by the application of force proximally of the resistance and so that said lumens will not collapse by deflection of said septum when the pressure differential of a dialysis system exists across said septum, said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff reinforcing material is not exposed to blood passing through said lumens.

2. The dual-lumen catheter of claim 1 wherein said septum is flat so that said lumens have D-shaped cross sections.

3. The dual-lumen catheter of claim 1 which includes a hollow conical tip on the distal end of said tube, the outside surface of said conical tip merging smoothly with the outside surface of the tube, and the inside surface of said conical tip merging smoothly with the inside surface of one of said lumens, the distal end of the other of said lumens being longitudinally spaced from the distal end of said tip.

4. The dual-lumen catheter of claim 3 wherein said conical tip forms a solid connection from the distal end of said septum and other lumen to the distal end of said tip, and the distal end of said reinforcing member engages said solid connection providing axial column strength so that longitudinal forces applied to said tube are transmitted to said tip via said reinforcing member so as to apply to the tip of said catheter a longitudinal force which urges said catheter in the distal direction.

5. The dual-lumen catheter of claim 3 wherein said conical tip is molded directly onto the end of said tube.

6. The dual-lumen catheter of claim 3 wherein the distal end of one of said lumens and said septum are connected to said conical tip by solid material.

7. The dual-lumen catheter of claim 3 wherein said conical tip is preformed and bonded to the end of said tube, a portion of said preformed tip extending into said tube to form the terminus of one of said lumens.

9. The dual-lumen catheter of claim 1 wherein said reinforcing member and a portion of said tube at the distal end thereof are interlocked.

10. The dual-lumen catheter of claim 1 which includes a kink-resisting spiral of reinforcing material wound around a substantial length of said tube.

11. The dual-lumen catheter of claim 10 wherein said spiral is embedded in the cylindrical wall of said tube.

12. The dual-lumen catheter of claim 1 wherein said reinforcing member includes a planar stiff material enclosed within said septum.

13. The dual-lumen catheter of claim 1 which includes a circumferential reinforcing member extending around the circumference of said cylindrical tube.

8. The dual-lumen catheter of claim i wherein said reinforcing member is made of nylon.

14. A dual-lumen catheter comprising:

an elongated flexible cylindrical tube made of a uniformly soft material which is compatible with the human body, said tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other in the axial direction, said septum comprising a pair of transversely spaced longitudinal webs formed as integral parts of said tube, and a reinforcing member comprising a flat strip of stiff material located longitudinally between said webs and bonded thereto so that said reinforcing member is completely enclosed by said webs of soft compatible material and is isolated from body fluids passing through said lumens, said reinforcing member extending along the length of said tube and being made of a material which is substantially stiffer than the material of said tube so that the catheter can be advanced longitudinally against a resistance by the application of force proximally of the resistance and so that said lumens will not collapse by deflection of said septum when a pressure differential exists across said septum.

15. The dual-lumen catheter of claim 14 wherein the transverse dimension of said reinforcing strip, in the direction parallel to said webs, is greater than the inside diameter of said tube so that said strip extends partially into the walls of the tube.

16. A method of introducing a dual-lumen catheter into a femoral vein of a patient for long-term use, said method comprising the steps of

making a subcutaneous tunnel on the abdomen of the patient, beginning above the inguinal ligament and extending downwardly to a point on the thigh that is proximate the femoral vein,

passing a dual-lumen catheter downwardly through said tunnel, and then bending the catheter and inserting it upwardly into said femoral vein, in the direction of blood flow within said vein,

said catheter being bent in a generally U-shaped configuration between the lower end of the tunnel and the point of access to said femoral vein, said U-bend being reinforced by a spiral winding of reinforcing material.

17. A multiple-lumen catheter comprising:

an elongated cylindrical silicone tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other in the axial direction.

one of said distal openings being formed by at least one aperture in the side wall of said tube opening into one of said lumens, and

a reinforcing solid-walled tube extending along the full length of, and embedded in the walls of, only one of said lumens for transmitting forces applied to the proximal end of said tube to said conical tip, and for preventing one of said lumens from collapsing when the pressure differential of a dialysis system exists across said septum.

18. The dual-lumen catheter of claim 17 wherein both said one lumen and said reinforcing member have D-shaped transverse cross sections.

19. The dual-lumen catheter of claim 17 wherein the inside walls of said reinforcing member are coated with the same material that forms said tube so that said tubular reinforcing member is isolated from body tissues and fluids.

20. A dual-lumen catheter comprising:

an elongated cylindrical tube made of a uniformly soft, elastic material and having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having D-shaped cross sections and distal openings which are offset from each other in the axial direction, said septum comprising a flat strip of stiff material extending longitudinal through said septum, the distal end of said strip being connected to the distal end of said tube and having apertures therein, portions of said tube extending transversely through said apertures to interlock said strip and said tube, said reinforcing member extending along the length of said tube and being made of a material which is substantially stiffer than the material of said tube so that the catheter can be advanced longitudinally against a resistance by the application of force proximally of the resistance and so that said lumens will not collapse by deflection of said septum when the pressure differential of a dialysis system exists across said septum.

21. A blood purification system comprising:

a dialysis system for purifying a patient'"'"'s blood; and

a dual-lumen catheter coupled to said dialysis system comprising;

an elongated cylindrical tube made of a soft, elastic material which is compatible with the human body, said tube having an internal septum extending along the length thereof to form first and second longitudinal lumens having distal openings which are offset from each other in the axial direction, wherein said dialysis system withdraws blood through said first lumen under a negative pressure and returns blood through said second lumen under a positive pressure, so that a pressure differential exists across said septum, and

a diametral reinforcing member extending along the length of said tube and made of a material which is substantially stiffer than the material of said tube so that the catheter can be advanced longitudinally against a resistance by the application of force proximally of the resistance and so that said first lumen will not collapse by deflection of said septum from the pressure differential produced across said septum by a dialysis system said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff reinforcing material is not exposed to blood passing through said lumens.

22. A dual-lumen catheter comprising:

an elongated cylindrical tube made of a uniformly soft, elastic material which is compatible with the human body, said tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other int he axial direction, and

a diametral reinforcing strip extending along the length of said septum, said reinforcing strip being sufficiently stiffer than the material of said tube to prevent collapse of either of said lumens by a pressure differential across the reinforced septum, said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff material of said reinforcing strip is not exposed to body fluids passing through said lumens.

23. A dual-lumen catheter comprising:

an elongated flexible cylindrical tube made of a soft polymer and having an internal planar septum extending axially therein to divide the interior of said tube into a pair of longitudinal lumens which are D-shaped in traverse section,

one of said lumens extending through the distal end of the catheter,

at least one aperture in the side wall of said tube opening into the other of said lumens,

said septum comprising a pair of parallel webs joined to the side walls of said tube, and a diametral reinforcing strip enclosed between said webs, so that said strip is completely embedded within said septum so that said reinforcing material is not exposed to body fluids passing through said lumens, said strip having a greater stiffness than said tube and webs in the axial direction, and

means for connecting the proximal ends of said lumens to two different fluid flow paths.

24. The dual-lumen catheter of claim 23 which includes a conically tapered tip whose circumference smoothly merges with the circumference of the catheter.

25. The dual-lumen catheter of claim 24 wherein the first lumen opens at the apex of the conically tapered tip.

26. The dual-lumen catheter of claim 24 wherein the tip of the catheter is attached to the distal end of said reinforcing member.

27. The dual-lumen catheter of claim 23 wherein said reinforcing member is enveloped in the catheter material on all the sides and ends.

28. The dual-lumen catheter of claim 23 wherein the proximal end of said reinforcing member is anchored at the lumen diversion portion of the catheter.

29. The dual-lumen catheter of claim 23 which includes additional spiral reinforcement along its circumference.

30. The dual-lumen catheter of claim 23 wherein said reinforcing member extends laterally beyond the internal diameter of the tube to anchor in the walls of the tube.

31. A dual-lumen hemodialysis catheter comprising:

an elongated cylindrical tube made of a uniformly soft, elastic material which is compatible with the human body, said tue having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other in the axial direction, and

a diametral reinforcing member extending along the length of said septum and made of a material which is substantially stiffer than the material of said tube, said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff reinforcing material is not exposed to blood passing through said lumens.

32. A dual-lumen catheter comprising:

an elongated flexible cylindrical tube made of a uniformly soft material which is compatible with the human body, said tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other int he axial direction, said septum comprising a pair of transversely spaced longitudinal webs formed as integral parts of said tube, and a reinforcing member comprising a flat strip of stiff material located longitudinally between said webs and bonded thereto so that said reinforcing member is completely enclosed by said webs of soft compatible material and is isolated from body fluids passing through said lumens, said reinforcing member extending along the length of said tube and being made of a material which is substantially stiffer than the material of said tube.

33. A blood purification system comprising:

a dialysis system for purifying a patient'"'"'s blood; and

a dual-lumen catheter coupled to said dialysis system comprising;

an elongated cylindrical tube made of a soft, elastic material which is compatible with the human body, said tube having an internal septum extending along the length thereof to form first and second longitudinal lumens having distal openings which are offset from each other in the axial direction, wherein said dialysis system withdraws blood through said first lumen under a negative pressure and returns blood through said second lumen under a positive pressure, so that a pressure differential exists across said septum, and

a diametral reinforcing member extending along the length of said tue and made of a material which is substantially stiffer than the material of said tube, said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff reinforcing material is not exposed to blood passing through said lumens.

34. A dual-lumen catheter comprising:

an elongated cylindrical tube made of a uniformly soft, elastic material which is compatible with the human body, said tube having an internal planar septum extending along the length thereof to form a pair of longitudinal lumens having distal openings which are offset from each other in the axial direction, and

a diametral reinforcing strip extending along the length of said septum, and made of a material which is substantially stiffer than the material of said tube, said reinforcing member being completely embedded within said soft compatible material of said tube and septum so that said stiff material of said reinforcing strip is not exposed to body fluids passing through said lumens.