Circumferential ablation device assembly and methods of use and manufacture providing an ablative circumferential band along an expandable member

• US 20020198521A1
• Filed: 06/06/2002
• Published: 12/26/2002
• Est. Priority Date: 07/08/1997
• Status: Active Grant

• Current Assignee: Mark A. Maguire
• Original Assignee: Mark A. Maguire
• Inventors: Maguire, Mark A.
• Granted Patent: US 6,758,847 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• 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 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00256 Creating an electrical block
• CPC Class Codes: A61B 2017/00318 Steering mechanisms
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00136 with polymer
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00238 porous
• CPC Class Codes: A61B 2018/00369 Heart valves
• CPC Class Codes: A61B 2018/00815 measured by a thermistor
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/044 the surgical action being effected by a circulating hot fluid
• CPC Class Codes: A61B 2090/3966 Radiopaque markers visible in an X-ray image
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49888 Subsequently coating
• CPC Class Codes: Y10T 29/49982 Coating

Abstract

A medical balloon catheter assembly includes a balloon having a permeable region and a non-permeable region. The balloon is constructed at least in part from a fluid permeable tube such that the permeable region is formed from a porous material which allows a volume of pressurized fluid to pass from within a chamber formed by the balloon and into the permeable region sufficiently such that the fluid may be ablatively coupled to tissue engaged by the permeable region. The non-permeable region is adapted to substantially block the pressurized fluid from passing from within the chamber and outwardly from the balloon. The porous material may be a porous fluoropolymer, such as porous polytetrafluoroethylene, and the pores may be created by voids that are inherently formed between an interlocking node-fibril network that makes up the fluoropolymer. Such voids may be created according to one mode by expanding the fluoropolymer. The balloon may be formed such that the porous material extends along both the permeable and non-permeable regions. In one mode of this construction, the porous material is porous along the permeable region but is non-porous along the non-permeable region, such as for example by expanding only the permeable region in order to render sufficient voids in the node-fibril network to provide permeable pores in that section. The voids or pores in the porous material may also be provided along both permeable and non-permeable sections but are substantially blocked with an insulator material along the non-permeable section in order to prevent fluid from passing through. The insulator material may be dip coated, deposited, or extruded with the porous material in order to fill the voids. The insulator material may in one mode be provided along the entire working length of the balloon and then selectively removed along the permeable section, or may be selectively exposed to only the non-permeable sections in order to fill the voids or pores there.

Claims

1. A method for forming a medical balloon catheter device assembly which is adapted to deliver a volume of fluid to a region of tissue in a body, comprising:

providing a tube having a first end portion, a second end portion and a permeable section formed at least in part from a porous material, the porous material having a plurality of pores which are adapted to allow a volume of pressurized fluid to pass from within and outwardly through the tube;

securing the first and the second end portions to a distal end portion of an elongate catheter body such that the tube forms at least in part a balloon which defines a pressurizeable chamber over the catheter body and which includes a working length that is adapted to radially expand from a radially collapsed condition to a radially expanded condition when the chamber is filled with the pressurized fluid, wherein the permeable section is positioned only along the working length; and

coupling the pressurizeable chamber with a distal port of a fluid passageway that extends along the catheter body between the distal port and a proximal port along the proximal end portion of the elongate catheter body which is adapted to couple to a pressurizeable fluid source.

2. The method of claim 1, further comprising:

after securing the end portions of the balloon along the elongate catheter body, sterilizing the balloon and elongate catheter body.

3. The method of claim 1, further comprising:

forming a taper along the working length of the balloon having a distally reducing outer diameter; and

positioning the permeable section along the taper.

4. The method of claim 3, wherein the step of forming the taper further comprises:

providing a first inner expansion element located along a proximal end portion of the working length within the chamber and a second inner expansion element located along a distal end portion of the working length within the chamber, the first inner expansion element being adapted to inflate to a larger diameter than the second inner expansion element;

fluidly coupling the first and the second inner expansion elements to one or more sources of inflation fluid; and

inflating the first and the second inner expansion elements with the inflation fluid to form a taper with a distally reducing outside diameter along the chamber working length extending between the first and second inner expansion elements.

5. The method of claim 1, wherein the tube is formed at least in part from a porous fluoropolymer having a plurality of voids which form the pores.

6. The method of claim 5, wherein the porous fluoropolymer includes a plurality of nodes which are interconnected with fibrils to form a node-fibril network such that the plurality of voids are formed between the nodes and interconnecting fibrils.

7. The method of claim 1, further comprising:

providing an ablation electrode to electrically couple to an electrical current source and also to the permeable section when the pressurizeable chamber is filled with an electrically conductive fluid.

8. The method of claim 7, further comprising:

securing the ablation electrode to the distal end portion of the elongate catheter body between the first and the second end portions of the tube such that the ablation electrode is positioned within the chamber.

9. The method of claim 1, wherein the tube further comprises a non-permeable section.

10. The method of claim 9 further comprising:

forming a taper along the working length of the balloon having a distally reducing outer diameter; and

positioning the non-permeable section along the taper.

11. The method of claim 9, wherein both the permeable and non-permeable sections of the tube are formed at least in part from the porous material.

12. The method of claim 11, further comprising substantially blocking the pores along the non-permeable section such that the blocked pores are substantially non-permeable to the volume of fluid when the fluid is pressurized.

13. The method of claim 12, wherein the step of substantially blocking the pores comprises blocking the pores with an insulator material.

14. The method of claim 13, wherein substantially blocking the pores comprises dip coating the non-permeable section with the insulator material.

15. The method of claim 13, wherein substantially blocking the pores comprises melting the insulator material to the non-permeable section.

16. The method of claim 13, wherein substantially blocking the pores comprises depositing the insulator material along the non-permeable section.

17. The method of claim 16, wherein depositing the insulator along the nonpermeable section is accomplished according to a deposition process selected from the group consisting of plasma depositing, vapor depositing, and ion beam depositing.

18. The method of claim 13, further comprising:

substantially blocking the pores along both the permeable section and the non-permeable section with the insulator material; and

selectively removing the insulator material such that the pores along the permeable section are left open and un-blocked and the pores along the non-permeable section are left blocked.

19. The method of claim 18, wherein selectively removing the insulator material from the permeable section comprises dissolving the insulator material along the permeable section with a solvent.

20. The method of claim 19, further comprising:

selectively masking the insulator material along the non-permeable section from being exposed to and dissolved by the solvent.