FLEXIBLE CATHETER SHAFT AND METHOD OF MANUFACTURE

• US 20150119859A1
• Filed: 10/09/2014
• Published: 04/30/2015
• Est. Priority Date: 10/24/2013
• Status: Active Grant

• Current Assignee: St. Jude Medical Cardiology Division Incorporated (Abbott Laboratories)
• Original Assignee: St. Jude Medical Cardiology Division Incorporated (Abbott Laboratories)
• Inventors: Dakin, Gregory James, Strong, Jeffrey John, Cajamarca, Tobias
• Granted Patent: US 9,913,961 B2
• Time in Patent Office: Days
• US Class Current: 604/526
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00511 Kidney
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/0052 Localized reinforcement, e.g. where only a specific part of the catheter is reinforced, for rapid exchange guidewire port
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: Y10T 29/49817 with other than ancillary treating or assembling

Abstract

The present disclosure provides a strong, flexible catheter shaft for use in a catheter system. The flexible catheter shaft includes a braided polyimide tube including one or more outer layers of material of varying flexibility. The flexible catheter shaft provides a shaft having sufficient stiffness and kink resistance to allow an operator to advance an electrode basket connected to the flexible catheter shaft through a guide catheter to a target ablation site without causing vessel trauma. The distal tip of the flexible catheter shaft is designed to have sufficient flexibility to reduce any risk of kicking out a guide catheter when tracking the electrode basket around turns into side branches or bifurcations in the vasculature of a patient and includes a distal spring coil.

Claims

1. A catheter shaft comprising a braided polyimide tube having a proximal portion and a distal portion, a substrate layer disposed within the braided polyimide tube, a spring coil disposed within the substrate layer and including a section extending past a distal end of the distal portion of the braided polyimide tube, and an outer spring coil disposed over at least a portion of the section of the spring coil extending past the distal end of the distal portion of the braided polyimide tube, wherein the proximal portion of the braided polyimide tube is covered by a first coating, wherein the distal portion of the braided polyimide tube and the outer spring coil is covered by a second coating, and wherein a pocket extends past a distal end of the outer spring coil.

2. The catheter shaft of claim 1 wherein the braided polyimide tube comprises stainless steel reinforcing strands selected from the group consisting of flat wires, round wires, and combinations thereof

3. The catheter shaft of claim 1 wherein the braided polyimide tube comprises 0.001 inch by 0.003 inch flat wire stainless steel strands.

4. The catheter shaft of claim 1 wherein substrate layer comprises a material selected from the group consisting of a polytetrafluoroethylene/polyimide composite material, a polyimide material, a polytetrafluoroethylene material, and combinations thereof

5. The catheter shaft of claim 1 wherein the spring coil is a flat wound coil having an inner diameter of about 0.030 inches.

6. The catheter shaft of claim 1 wherein the outer spring coil has a wind direction opposite the wind direction of the spring coil.

7. The catheter shaft of claim 1 wherein the first coating covering the proximal portion of the braided polyimide tube comprises a first layer and a second layer covering the first layer.

8. The catheter shaft of claim 1 wherein the second coating covering the distal portion of the braided polyimide tube and the outer spring coil comprises a single layer comprising a polyether block amide material.

9. The catheter shaft of claim 1 wherein the second coating covering the distal portion of the braided polyimide tube and outer spring coil comprises at least two polyether block amide material.

10. A method of manufacturing a catheter shaft, the method comprising:

providing a braided polyimide tube having at least one layer disposed on top of the tube and having a substrate layer disposed within the braided polyimide tube;

removing from a distal portion of the braided polyimide tube the at least one layer;

introducing a new layer of material onto the distal portion of the braided polyimide tube;

introducing a spring coil inside of the substrate layer wherein a section of the spring coil extends beyond a distal end of the braided polyimide tube;

introducing an outer spring coil onto at least a portion of the section of the spring coil that extends beyond a distal end of the braided polyimide tube;

introducing a layer of material onto the outer spring coil; and

forming a pocket on a distal end of the outer spring coil.

11. A catheter shaft comprising a braided polyimide tube having a proximal portion and a distal portion, a substrate layer disposed within the braided polyimide tube, and a spring coil disposed within the substrate layer and including a section extending past a distal end of the distal portion of the braided polyimide tube, wherein the proximal portion of the braided polyimide tube is covered by a first coating, wherein the distal portion of the braided polyimide tube is covered by a second coating, wherein the section of the spring coil that extends past the distal end of the braided polyimide tube is covered by a third coating, and wherein a pocket extends past a distal end of the spring coil.

12. The catheter shaft of claim 11 wherein the braided polyimide tube comprises stainless steel reinforcing strands selected from the group consisting of flat wires, round wires, and combinations thereof

13. The catheter shaft of claim 11 wherein the braided polyimide tube comprises 0.001 inch by 0.003 inch flat wire stainless steel strands.

14. The catheter shaft of claim 11 wherein substrate layer comprises a material selected from the group consisting of a polytetrafluoroethylene/polyimide composite material, a polyimide material, a polytetrafluoroethylene material, and combinations thereof

15. The catheter shaft of claim 11 wherein the spring coil is a flat wound coil having an inner diameter of about 0.030 inches.

16. The catheter shaft of claim 11 wherein the first coating covering the proximal portion of the braided polyimide tube comprises a first layer and a second layer covering the first layer.

17. The catheter shaft of claim 11 wherein the second coating covering the distal portion of the braided polyimide tube comprises a single layer comprising a polyether block amide material.

18. The catheter shaft of claim 11 wherein the third coating covering the section of the spring coil that extends past the distal end of the braided polyimide tube comprises at least one polyether block amide material.

19. A method of manufacturing a catheter shaft, the method comprising:

providing a braided polyimide tube having at least one layer disposed on top of the tube and having a substrate layer disposed within the braided polyimide tube;

removing from a distal portion of the braided polyimide tube the at least one layer;

introducing a new layer of material onto the distal portion of the braided polyimide tube;

introducing a spring coil inside of the substrate layer wherein a portion of the spring coil extends beyond a distal end of the braided polyimide tube;

introducing a layer of material onto the portion of the spring coil that extends beyond the distal end of the braided polyimide tube; and

forming a pocket on a distal end of the spring coil.

20. The method of claim 19 wherein the removing is done with laser ablation.