Renal Nerve Neuromodulation Device

• US 20130226166A1
• Filed: 02/28/2012
• Published: 08/29/2013
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: Trisalus Life Sciences Incorporated
• Original Assignee: Surefire Medical, Inc.
• Inventors: Chomas, James E., Weldon, Norman R., Pinchuk, Leonard
• Granted Patent: US 9,089,341 B2
• Time in Patent Office: Days
• US Class Current: 606/33
• CPC Class Codes: A61B 18/1206 Generators therefor
• 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 2018/00178 Electrical connectors
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00267 having a basket shaped structure
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2018/00511 Kidney
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing

Abstract

A neuromodulation device includes an ablation valve with electrodes provided about its circumference. The valve dynamically reacts to fluid pressure within the vessel. When a pressure within and distal said ablation valve is greater than the body fluid pressure within the vessel, said ablation valve closes and the electrodes move out of contact with the endothelium of the vessel. When a pressure within and distal the ablation valve is less than the body fluid pressure upstream of the valve, the valve opens such that the electrodes are in circumferential contact with the endothelium. Fluid can be injected into the valve to alter the local pressure about the valve and force the electrodes into contact with the endothelium.

Claims

1. A neuromodulation device for use in a vessel having an endothelium and carrying body fluid with a fluid pressure, comprising:

a) an elongate flexible introducer having a proximal end and distal end;

b) an expandable ablation valve at said distal end of said introducer, said ablation valve having a proximal surface, a distal surface, a circumference, and a plurality of electrodes displaced about said circumference, said ablation valve adapted to dynamically react to fluid pressure within the vessel such that,

i) when a pressure within and on said distal surface of said ablation valve is less than the fluid pressure on said proximal surface of said ablation valve, said ablation valve is in a retreated configuration in which said electrodes are out of circumferential contact with the endothelium of the vessel, and

ii) when said pressure within and on said distal surface of said ablation valve is greater than the fluid pressure on said proximal surface of said ablation valve, said ablation valve is in a contact configuration in which said electrodes are in circumferential contact with the endothelium of the vessel; and

c) a conductor extending along said introducer, said conductor having a distal end electrically coupled to said electrodes of said ablation valve and a proximal end extended to a terminal for coupling to a RF generator.

2. A neuromodulation device according to claim 1, wherein:

said introducer is a catheter defining a lumen having a distal opening that is located at an interior of said ablation valve.

3. A neuromodulation device according to claim 1, wherein:

a proximal end of said ablation valve is located substantially coincident with said distal opening of said lumen.

4. A neuromodulation device according to claim 1, wherein:

said ablation valve expands to said contact configuration during diastole, and moves to said retreated configuration during systole.

5. A neuromodulation device according to claim 1, wherein:

said ablation valve comprises an inner layer defined by electrospun fibers, and an expandable structure over said inner layer comprising a braid of filaments which cross over each other, at least a plurality of said filaments having a spring bias to assume a preferred crossing angle relative to each other, a proximal end of said braid of filaments radially collapsed and coupled to the distal end of said elongate introducer.

6. A neuromodulation device according to claim 5, wherein:

in each of said contact configuration and said retreated configuration, said ablation valve has respective frustoconical shapes.

7. A neuromodulation device according to claim 5, wherein:

said filaments define at least a plurality of electrodes.

8. A neuromodulation device according to claim 7, wherein:

said filaments comprise insulated wires, and each said electrode is defined at a portion of said wire at which a portion of the insulation has been removed to expose an interior conductive metal of said wire.

9. A neuromodulation device according to claim 7, wherein:

said filaments include non-conductive filaments.

10. A neuromodulation device according to claim 7, wherein:

an outer layer of electrospun fibers provided over said filaments.

11. A neuromodulation device according to claim 7, wherein:

said device is bipolar.

12. A neuromodulation device according to claim 11, wherein:

said electrodes includes first and second electrically isolated sets of electrodes, and said conductor comprises first and two electrically isolated conductors, said first conductor electrically coupled to said first set of electrodes, and said second electrode coupled to said second set of electrodes.

13. A neuromodulation device according to claim 7, wherein:

said device is monopolar.

14. A neuromodulation device according to claim 1, further comprising:

a sleeve into which said introducer and ablation valve are provided for delivery to a treatment site, said introducer longitudinally displaceable relative to said sleeve to advance said ablation valve out of a distal end of said sleeve.

15. A neuromodulation device according to claim 1, further comprising:

an inner catheter having a proximal end and a distal end and extending through said introducer, wherein a distal end of said ablation valve is coupled to said distal end of said inner catheter, and said inner catheter and introducer are longitudinally translatable relative to each other to move said ablation valve between said open and closed configurations.

16. A neuromodulation device according to claim 1, further comprising:

said RF generator electrically coupled to said terminal.

17. A neuromodulation device for use in a vessel having an endothelium and carrying body fluid with a fluid pressure, comprising:

a) an elongate flexible outer catheter having a proximal end and distal end;

b) an inner catheter extending through said outer catheter, said inner catheter having proximal and distal ends;

c) an expandable ablation valve having proximal and distal ends, said proximal end of said ablation valve coupled to said distal end of said outer catheter, and said distal end of said ablation valve coupled to said distal end of said inner catheter, said ablation valve having a circumference, and a plurality of electrodes displaced about said circumference,

wherein longitudinal displacement of said inner catheter relative to said outer catheter in a first direction to cause said distal ends of said inner and outer catheters to move away from one another causes said ablation valve to move into a reduced diameter retreated configuration, and longitudinal displacement of said inner and outer catheters in an opposite second direction causes to said ablation valve to radially expand into a enlarged diameter open configuration; and

d) a conductor extending along said outer catheter, said conductor having a distal end electrically coupled to said electrodes of said ablation valve and a proximal end extended to a terminal for coupling to a RF generator,

18. A device for neuromodulation of a vessel, comprising:

a) an introducer including a proximal end and a distal end;

b) an ablation valve coupled to said distal end of said introducer, said ablation valve movable between a first substantially tubular closed configuration to a second flared open configuration, said ablation valve including,

an inner fiber layer formed by electrostatically depositing or spinning polymeric first filaments over a mandrel, and

a braid layer provided over said inner fiber layer, said braid layer having a substantially including a plurality of elongate conductive second filaments each coated in an electrically insulative coating, a portion of said second filaments having the insulative coating removed therefrom to expose the inner second filaments thus defining respective electrodes, said second filaments each having a diameter of 0.025 mm to 0.127 mm, said second filaments having a proximal end, a distal end, and a length extending therebetween, said proximal ends secured relative to each other, said second filaments along said lengths distal of said proximal ends not bonded to each other such that said second filaments are movable relative to each other, said wherein in said second configuration said second filaments cross one another at an angle of 100°

to 150°

, and said first filaments have a Young'"'"'s modulus of elasticity greater than 100 MPa; and

c) an electrical conductor extending along said introducer, said conductor having a proximal end and distal end, said distal end coupled to said proximal end of said filaments such that said conductor and said electrodes are electrically coupled,

19. A method of neuromodulation within a vessel, the vessel having an endothelium and at least one nerve about the vessel, comprising:

a) providing an expandable ablation valve having a proximal surface, a circumference, and a plurality of electrodes displaced about said circumference, said ablation valve adapted to dynamically react to fluid pressure within the vessel;

b) advancing said ablation valve in a collapsed state to a target location;

c) releasing said ablation valve from said collapsed state to permit said ablation valve to dynamically react to fluid pressure about said ablation valve such that said electrodes of said ablation valve move into and out of contact with the endothelium according to said fluid pressure abut said ablation valve; and

d) when said electrodes of said ablation valve are in contact with the endothelium of the vessel, applying sufficient RF energy to said electrodes to effect neuromodulation.

20. A method according to claim 19, wherein:

said ablation valve automatically expands into contact with said endothelium during diastole, and is forced out of contact with said endothelium during systole.

21. A method according to claim 19, wherein:

said ablation valve automatically expands into contact with said endothelium when fluid pressure within and on a proximal side of said ablation valve is greater than fluid pressure on a distal side of said ablation valve, and is forced away from said endothelium when fluid pressure on a distal side of said ablation valve is greater than fluid pressure on a proximal side of said ablation valve.

22. A method according to claim 21, further comprising:

injecting fluid into said ablation valve to increase a fluid pressure within said ablation valve.

23. A method according to claim 19, wherein:

RF energy is only applied to said electrodes when said electrodes are in contact with said endothelium.

24. A method according to claim 23, further comprising:

detecting an impedance in an RF circuit to determine when said electrodes are in contact with said endothelium.

25. A method according to claim 23, further comprising:

detecting a signal from a physiological monitor to determine when said electrodes are in contact with said endothelium.

26. A method according to claim 25, wherein:

said physiological monitor is an ECG.

27. A method of neuromodulation within a vessel, the vessel having an endothelium and at least one nerve about the vessel, comprising:

a) providing an expandable ablation valve having a circumference, and a plurality of electrodes displaced about said circumference;

b) advancing said ablation valve in a reduced diameter configuration to a target location;

c) expanding said ablation valve from said reduced diameter configuration to causes said electrodes to contact the endothelium, said ablation valve dynamically reacting to fluid pressure about said ablation valve such that said electrodes of said ablation valve move into and out of contact with the endothelium according to said fluid pressure about proximal and distal locations of said ablation valve; and

d) when said electrodes of said ablation valve are in contact with the endothelium of the vessel, applying sufficient RF energy to said electrodes to effect neuromodulation.

28. A method according to claim 27, further comprising:

increasing a force of expansion of said electrodes against the endothelium to increase a duty cycle of the device.