Catheter with flexible tip and shape retention

• US 20040015151A1
• Filed: 07/22/2002
• Published: 01/22/2004
• Est. Priority Date: 07/22/2002
• Status: Active Grant

• Current Assignee: Chambers Technology LLC
• Original Assignee: Chambers Technology LLC
• Inventors: Chambers, Jeffrey W.
• Granted Patent: US 7,115,134 B2
• Time in Patent Office: Days
• US Class Current: 604/532
• CPC Class Codes: A61M 2025/0063 having means, e.g. stylets, mandrils, rods or wires to reinforce or adjust temporarily the stiffness, column strength or pushability of catheters which are already inserted into the human body
• CPC Class Codes: A61M 2025/09075 having a core without a coil possibly combined with a sheath
• CPC Class Codes: A61M 2025/09116 Design of handles or shafts or gripping surfaces thereof for manipulating guide wires
• CPC Class Codes: A61M 2025/0915 having features for changing the stiffness
• CPC Class Codes: A61M 2210/125 Heart
• CPC Class Codes: A61M 25/0041 pre-formed, e.g. specially adapted to fit with the anatomy of body channels urethral catheters A61F2/04
• CPC Class Codes: A61M 25/0136 Handles therefor

Abstract

An improved apparatus and method to catheterize passages is disclosed. The present invention provides a catheter having a soft flexible pre-formed distal tip, that when used in combination with commercially available guidewires of variable stiffness, results in the ability to control the direction and angle of wire advancement allowing cannulation of body passages, including those that arise at acute angles. The catheter can have a longitudinal axis, a proximal section and a distal section having a soft flexible pre-formed tip having a curvature of ninety degrees or greater and shape retention. The catheter can have an inner wall that defines a lumen that runs along said longitudinal axis forming a single continuous tube, a reinforcement braid disposed over the inner wall, and an outside covering disposed over the reinforcement braid. A spacer can be added between said wall liner and said reinforcement braid in the proximal end.

Claims

1. A catheter generally flexible to conform to vascular areas of a body for use with a variable stiffness guidewire, comprising:

said catheter extending from a proximal end to a distal end;

said catheter having a lumen therein, the lumen sized to receive the guidewire therein;

said catheter having a pre-formed curved portion in its distal end (curved distal tip) of ninety degrees or greater;

the curved distal tip rotatable to different orientations by rotations of the proximal end of the catheter; and

the curved distal tip having

a flexibility to permit straightening of the curved distal tip by advancing the guidewire therethrough, and

shape retention memory to return to the original angle of curvature.

2. The catheter of claim 1, wherein the proximal end to the distal end forms a first section, the pre-formed curved portion is less flexible than the first section.

3. The catheter of claim 1, wherein the curved distal tip includes a first straight subsection, a pre-formed curved subsection, and a second straight subsection.

4. The catheter of claim 1, wherein the curved distal tip includes a straight subsection and a pre-formed curved subsection.

5. The catheter of claim 1, wherein the curved distal tip includes a pre-formed curved subsection and a straight subsection.

6. The catheter of claim 3, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

7. The catheter of claim 4, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

8. The catheter of claim 5, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

9. The catheter of claim 3, wherein the pre-formed curved subsection is disposed between the first straight subsection and the second straight subsection.

10. The catheter of claim 1, wherein an amount of curvature of the curved distal tip can be controlled by a variable stiffness guidewire.

11. The catheter of claim 1, wherein the pre-formed curved portion is formed of fused nylon.

12. The catheter of claim 1, wherein the pre-formed curved portion is formed of plastic.

13. The catheter of claim 1, wherein the pre-formed curved portion is formed of polyurethane.

14. The catheter of claim 1, wherein the pre-formed curved portion includes a wire having shape memory characteristics.

15. The catheter of claim 1, wherein the pre-formed curved portion includes a braided metal member.

16. A catheter generally flexible to conform to vascular areas of a body, comprising:

said catheter extending from a proximal end to a distal end and having an intermediate section therebetween;

a variable stiffness guidewire slidably disposable within a lumen of the catheter, the guidewire having a guidewire proximal end and extending to a guidewire distal end;

the lumen sized to receive the guidewire therein;

the catheter having a pre-formed curved portion in its distal end (curved distal tip);

the curved distal tip rotatable to different orientations by rotations of the proximal end of the catheter; and

the curved distal tip having a flexibility to permit straightening of the curved distal tip by sliding the guidewire relative to the catheter.

17. The catheter of claim 16, wherein the guidewire has a variable stiffness near the distal end with decreasing stiffness toward a distal tip of the guidewire.

18. The catheter of claim 16, wherein the curved distal tip includes a first straight subsection, a pre-formed curved subsection, and a second straight subsection.

19. The catheter of claim 16, wherein the curved distal tip includes a straight subsection and a pre-formed curved subsection.

20. The catheter of claim 16, wherein the curved distal tip includes a pre-formed curved subsection and a pre-formed straight subsection.

21. The catheter of claim 18, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

22. The catheter of claim 19, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

23. The catheter of claim 20, wherein a bending stiffness of the straight subsection is greater than a bending stiffness of the pre-formed curved subsection.

24. The catheter of claim 18, wherein the pre-formed curved subsection is disposed between the first straight subsection and the second straight subsection.

25. A method for catheterizing body passages, comprising the steps of:

introducing a variable stiffness guidewire into a body passage, the guidewire having a guidewire proximal end and a guidewire distal end;

disposing a lumen of a catheter over the variable stiffness guidewire, the catheter generally flexible to conform to vasculature of a body, the catheter extending from a proximal end to a distal end and having an intermediate portion therebetween, the catheter having a pre-formed curved portion in its distal end (curved distal tip), the curved portion having a flexibility to permit straightening of the curved distal tip by sliding the guidewire relative to the catheter;

slidably adjusting the variable stiffness guidewire relative to the catheter and straightening the pre-formed curved portion;

introducing the guidewire and catheter into a body passage;

advancing the catheter and guidewire through the body passage to an entrance of a first branched passageway;

withdrawing the guidewire into the catheter allowing the catheters curved distal tip to resume its pre-formed angle of curvature;

advancing the guidewire and using the plurality of forces the desired angle of curvature of the curved distal tip of the catheter can be created, thereby allowing the guidewire to be advanced into the first branched passageway; and

cannulating successively branched passageways by cooperatively manipulating and slidably adjusting the relative position of the guidewire and catheter from the exterior of the body until the desired body passageway is reached.

26. The method of claim 25, further comprising the steps of:

rotating the proximal end of the catheter to rotate the distal tip to different orientation, and

advancing further the guidewire and catheter.

27. The method of claim 25, further comprising the step of administering medication through the catheter.

28. The method of claim 25, further comprising the steps of removing the catheter and advancing an angioplasty balloon over the guidewire.

29. The method of claim 25, further comprising the steps of removing the catheter and advancing a stent over the guidewire.

30. The method of claim 25, further comprising removing the guidewire.

31. A catheter for use in combination with a variable stiffness guidewire, comprising:

a longitudinal axis, a proximal section and a distal section;

said distal section comprising a soft flexible pre-formed curved portion in its distal end having a curvature of ninety degrees or greater and shape retention properties;

said catheter having

an inner wall that defines a lumen that runs along said longitudinal axis forming a single continuous tube, a reinforcement braid disposed over said inner wall, and

an outside covering disposed over said reinforcement braid;

said catheter proximal end further comprising a spacer disposed between said wall liner and said reinforcement braid; and

said reinforcement braid doubled over the proximately two-thirds of the catheter.

32. A catheter for use with a variable stiffness guidewire with a pre-formed curved distal tip, comprising:

said catheter generally flexible to conform to vascular areas of a body, said catheter extending from a proximal end to a distal end;

said catheter having a lumen therein, the lumen sized to receive a guidewire therein;

the distal tip rotatable to different orientations by rotations of the proximal end of the catheter; and

the distal tip having flexibility to permit bending of the distal tip by advancing the variable stiffness guidewire therethrough.