Multi-electrode catheter assemblies for renal neuromodulation and associated systems and methods

• US 9,452,017 B2
• Filed: 08/12/2015
• Issued: 09/27/2016
• Est. Priority Date: 05/11/2012
• Status: Active Grant

• Current Assignee: Medtronic Ireland Manufacturing Unlimited Company (Medtronic Plc)
• Original Assignee: Medtronic Ardian Luxembourg SARL (Medtronic Plc)
• Inventors: Chang, William W., Goshgarian, Justin, Mauch, Kevin Michael, Rivera, Leonila, Shin, Sukyoung, Tran, Don H.
• Primary Examiner(s): Wieland, Robert N
• Application Number:
  US14/824,155
• Publication Number:
  US 20160066988A1
• Time in Patent Office: 412 Days
• US Class Current: 1/1
• 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 2018/00059 Material properties
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• 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 2018/1435 Spiral
• CPC Class Codes: A61B 2018/1465 Deformable electrodes
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61M 2025/0915 having features for changing the stiffness
• CPC Class Codes: A61M 2205/6063 Optical identification systems
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61N 1/36057 adapted for stimulating afferent nerves

Abstract

Catheter apparatuses, systems, and methods for achieving renal neuromodulation by intravascular access are disclosed herein. One aspect of the present technology, for example, is directed to a treatment device having a multi-electrode array configured to be delivered to a renal blood vessel. The array is selectively transformable between a delivery or low-profile state (e.g., a generally straight shape) and a deployed state (e.g., a radially expanded, generally spiral/helical shape). The multi-electrode array is sized and shaped so that the electrodes or energy delivery elements contact an interior wall of the renal blood vessel when the array is in the deployed (e.g., spiral/helical) state. The electrodes or energy delivery elements are configured for direct and/or indirect application of thermal and/or electrical energy to heat or otherwise electrically modulate neural fibers that contribute to renal function.

Claims

1. A renal denervation catheter for treatment of a human patient, the renal denervation catheter comprising:

a shaft having a proximal end and a distal end, wherein the distal end of the shaft is configured for intravascular delivery over a guide wire to a renal blood vessel of the patient;

a pre-shaped helical structure disposed at or proximate to the distal end of the shaft, wherein the helical structure is configured to transform between a low-profile delivery state and a deployed state tending to assume the shape of the pre-shaped helical structure, and wherein the helical structure is composed, at least in part, of nitinol; and

a plurality of energy delivery elements carried by the helical structure,

wherein the shaft and the helical structure together define a guide wire lumen therethrough, and wherein—

the guide wire lumen is configured to slidably receive the guide wire to locate the helical structure at a target treatment site within the renal blood vessel of the patient and to restrain the helical structure in the low-profile delivery state, and

the helical structure is reversibly transformable from the delivery state to the deployed state by proximally moving the guide wire through the guide wire lumen until a distalmost end of the guide wire is disposed within the helical structure.

2. The renal denervation catheter of claim 1 wherein:

the plurality of energy delivery elements are individually connectable to an energy source external to the patient; and

the energy source is capable of individually controlling the energy delivered to each energy delivery element during therapy.

3. The renal denervation catheter of claim 1 wherein the plurality of energy delivery elements are composed of gold.

4. The renal denervation catheter of claim 1 wherein the plurality of energy delivery elements comprise a series of band electrodes.

5. The renal denervation catheter of claim 4 wherein at least one of the band electrodes comprises tapered end portions, and wherein the tapered end portions are configured to provide an obtuse angle between an outer surface of the support structure and an outer surface of the at least one band electrode.

6. The renal denervation catheter of claim 1 wherein the plurality of energy delivery elements comprise four electrodes carried by the helical structure.

7. The renal denervation catheter of claim 1 wherein the helical structure is configured to transform between the delivery state and the deployed state while at least the distalmost end of the guide wire is within the guide wire lumen and is disposed within the helical structure.

8. The renal denervation catheter of claim 1 wherein the helical structure comprises a shape-recovery force sufficient to overcome a straightening force provided by a distal region of the guide wire to transform the helical structure to the deployed state when the distalmost end of the guide wire is generally aligned with a distal tip of the helical structure.

9. The renal denervation catheter of claim 1 wherein a distal portion of the helical structure further comprises a flexible curved tip terminating in an open distal end of the guide wire lumen such that, when the helical structure is in the deployed state and the distalmost end of the guide wire is advanced from the open distal end, the guide wire distalmost end is directed away from a wall of the renal blood vessel.

10. The renal denervation catheter of claim 9 wherein the flexible curved tip is composed of polyether block amide copolymer.

11. The renal denervation catheter of claim 9 wherein the flexible curved tip is composed of a thermoplastic polyether urethane material.

12. The renal denervation catheter of claim 1 wherein the helical structure is composed, at least in part, of a nitinol multifilar stranded wire.

13. A method of treating a hypertensive human patient, the method comprising:

transluminally delivering a renal neuromodulation catheter over a guide wire to a target treatment site within a renal artery of the patient, wherein the catheter comprises—

a shaft; and

a multi-electrode array at a distal region of the shaft, the multi-electrode array comprising a support structure composed, at least in part, of nitinol;

proximally withdrawing the guide wire to transform the multi-electrode array from a low-profile delivery state to a deployed state in which the support structure has a radially expanded, generally spiral form shaped and sized to contact the wall of the renal artery and to allow blood to flow in and around the array; and

selectively delivering radio-frequency (RF) energy from one or more electrodes of the multi-electrode array to renal nerves along the renal artery of the patient, thereby at least partially blocking neural traffic to and/or from a kidney of the patient.

14. The method of claim 13 wherein proximally withdrawing the guide wire to transform the multi-electrode array comprises partially withdrawing the guide wire from the multi-electrode array such that at least a portion of the guide wire remains in the multi-electrode array after the multi-electrode array transforms to the deployed state.

15. The method of claim 13 wherein proximally withdrawing the guide wire to transform the multi-electrode array comprises completely withdrawing the guide wire from the multi-electrode array such that a distalmost end of the guide wire is withdrawn to a point proximal of the multi-electrode array.

16. The method of claim 13 wherein selectively delivering RF energy from one or more electrodes of the multi-electrode array comprises selectively delivering RF energy in a bipolar fashion between the electrodes of the multi-electrode array.

17. The method of claim 13 wherein selectively delivering RF energy from one or more electrodes of the multi-electrode array comprises delivering RF energy in a monopolar fashion between a selected electrode and an external ground pad attached to skin of the patient.

18. The method of claim 13, further comprising monitoring a parameter of the one or more electrodes and/or tissue proximate to the renal nerves within the patient during therapy.

19. The method of claim 18 wherein monitoring a parameter comprises monitoring temperature and/or impedance.

20. The method of claim 18, further comprising controlling the delivery of RF energy from one or more electrodes to the renal nerves in response to the monitored parameter.

21. The method of claim 13 wherein selectively delivering RF energy from the one or more electrodes to renal nerves along the renal artery comprises thermally altering one or more renal nerves of the patient.

22. The method of claim 13 wherein selectively delivering RF energy from the one or more electrodes to renal nerves along the renal artery comprises ablating one or more renal nerves of the patient.

23. The method of claim 13 wherein selectively delivering RF energy from the one or more electrodes to renal nerves along the renal artery results in a reduction in renal sympathetic nerve activity of the hypertensive patient.

24. The method of claim 13 wherein at least partially blocking neural traffic to and/or from the kidney of the patient results in a therapeutically beneficial reduction in blood pressure of the hypertensive patient.