Apparatuses for renal neuromodulation and associated systems and methods

• US 8,548,600 B2
• Filed: 09/14/2012
• Issued: 10/01/2013
• Est. Priority Date: 04/08/2002
• Status: Expired due to Term

• Current Assignee: Medtronic Ardian Luxembourg SARL (Medtronic Plc)
• Original Assignee: Medtronic Ardian Luxembourg SARL (Medtronic Plc)
• Inventors: Deem, Mark, Gifford, Hanson III, Demarais, Denise, Sutton, Douglas, Thai, Erik, Gelfand, Mark, Levin, Howard R.
• Primary Examiner(s): BOCKELMAN, MARK
• Application Number:
  US13/619,851
• Publication Number:
  US 20130012866A1
• Time in Patent Office: 382 Days
• Field of Search: 604/21, 604/103.01, 607/44, 607/101, 607/116, 606/41
• US Class Current: 607/101
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• 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 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/00071 Electrical conductivity
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/0022 Balloons
• 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 2018/00505 Urinary tract
• CPC Class Codes: A61B 2018/00511 Kidney
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00613 Irreversible electroporation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00904 Automatic detection of target tissue
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61M 25/0023 : by the form of the lumen, e.g. cross-section, variable diameter
• CPC Class Codes: A61M 5/14 : Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61N 1/0412 : Specially adapted for transcutaneous electroporation, e.g. including drug reservoirs
• CPC Class Codes: A61N 1/05 : for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0551 : Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/18 : Applying electric currents by contact electrodes
• CPC Class Codes: A61N 1/205 : for promoting a biological process
• CPC Class Codes: A61N 1/326 : for promoting growth of cells, e.g. bone cells
• CPC Class Codes: A61N 1/327 : for enhancing the absorption properties of tissue, e.g. by electroporation
• CPC Class Codes: A61N 1/36007 : of urogenital or gastrointestinal organs, e.g. for incontinence control
• CPC Class Codes: A61N 1/36017 : with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36057 : adapted for stimulating afferent nerves
• CPC Class Codes: A61N 1/36103 : Neuro-rehabilitation; Repair or reorganisation of neural tissue, e.g. after stroke
• CPC Class Codes: A61N 1/36114 : Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36117 : for treating hypertension
• CPC Class Codes: A61N 1/36139 : with automatic adjustment
• CPC Class Codes: A61N 2007/0021 : Neural system treatment
• CPC Class Codes: A61N 2007/003 : Destruction of nerve tissue
• CPC Class Codes: A61N 5/00 : Radiation therapy ultrasound therapy A61N7/00; devices or apparatus applicable to both therapy and diagnosis A61B6/00
• CPC Class Codes: A61N 7/00 : Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

Methods and apparatus are provided for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. It is expected that renal neuromodulation (e.g., denervation) may, among other things, reduce expansion of an acute myocardial infarction, reduce or prevent the onset of morphological changes that are affiliated with congestive heart failure, and/or be efficacious in the treatment of end stage renal disease. Embodiments of the present invention are configured for percutaneous intravascular delivery of pulsed electric fields to achieve such neuromodulation.

Claims

1. An apparatus for renal neuromodulation, the apparatus comprising:

an electric field generator configured to deliver non-pulsed thermal RF energy to renal nerves that modulate renal neural activity of a human patient;

a catheter having a distal portion configured for percutaneous placement within a renal blood vessel of the patient;

an expandable balloon at the distal portion of the catheter, wherein the expandable balloon is selectively transformable between a low-profile, delivery configuration and a deployed configuration sized to fit within the renal blood vessel, and wherein the expandable balloon comprises a weeping balloon for infusion of a selected agent therefrom; and

a helical conductor electrically connectable to the electric field generator and arranged about the expandable balloon such that, when the balloon is in the deployed configuration, the helical conductor is configured to deliver the thermal RF energy through an inner wall of the renal blood vessel to neural fibers that innervate a kidney of the patient to reduce renal sympathetic nerve activity.

2. The apparatus of claim 1 wherein, in the deployed configuration, the balloon is sized to occlude the renal blood vessel.

3. The apparatus of claim 1 wherein the energy from the helical conductor is sufficient to cause at least partial renal denervation.

4. The apparatus of claim 1 wherein the energy from the helical conductor is sufficient to cause at least partial ablation of at least one neural fiber.

5. The apparatus of claim 1 wherein the helical conductor is sized and shaped to physically contact the inner wall of the renal blood vessel when the balloon is in the deployed configuration.

6. The apparatus of claim 1 wherein, when the balloon is in the deployed configuration, the helical conductor is configured to deliver the energy through the inner wall of the renal blood vessel in a helical pattern.

7. The apparatus of claim 1, further comprising one or more sensors at the distal portion of the catheter for monitoring and/or controlling effects of the energy delivery.

8. The apparatus of claim 7 wherein at least one of the sensors comprises a thermocouple for monitoring temperature.

9. The apparatus of claim 1 wherein the catheter is configured for placement in the renal blood vessel over a guidewire.

10. The apparatus of claim 1 wherein the balloon is collapsed for delivery to the renal blood vessel within a sheath, and further wherein the balloon is configured to expand into contact with the wall of the renal blood vessel after exiting from the sheath.

11. The apparatus of claim 1 wherein the selected agent comprises saline.

12. The apparatus of claim 1 wherein the balloon, when in the low-profile delivery configuration, is sized to fit within a sheath, and further wherein the balloon is configured to expand into contact with the wall of the renal blood vessel after exiting from the sheath.

13. A renal neuromodulation system, comprising:

an electric field generator configured to deliver a non-pulsed thermal RF field to renal nerves that modulate renal neural activity of a human patient; and

a catheter comprising (a) a shaft having a lumen therethrough, (b) an expandable distal balloon, wherein the balloon comprises a weeping balloon for infusion of a selected agent therefrom, and (c) at least one electrode, the catheter being transformable between—

a reduced delivery configuration for percutaneous intravascular placement within renal vasculature of the patient, and

an expanded treatment configuration for delivering the thermal RF field to one or more of the renal nerves,

wherein the at least one electrode is electrically connectable to the electric field generator and comprises a helical configuration arranged about and expandable by the balloon for delivering the thermal RF field to one or more renal nerves to thermally induce modulation of a function of the one or more renal nerves when the catheter is at least partially located within the renal vasculature.

14. The system of claim 13 wherein the at least one electrode is affixed to an outside surface of or embedded within a wall of the balloon.

15. The apparatus of claim 13 wherein, in the deployed configuration, the balloon is sized and shaped to physically contact a wall of the renal vasculature and is configured to act as an insulator to increase impedance within an interior of the renal vasculature and thereby direct an electric field along a desired electric flow path through the wall of the renal vasculature when the balloon is expanded into contact therewith.

16. The system of claim 13 wherein the catheter is configured for infusion of one or more agents into the renal vasculature before, during, or after delivery of the electric field to the one or more renal nerves.

17. The system of claim 16 wherein the one or more agents are chosen from the group consisting of saline, heparinized saline, poloxamer-188 or other protective agents, or anti-proliferative agents.

18. The system of claim 13 wherein the at least one electrode comprises a first dynamically controllable electrode, and wherein the catheter further comprises at least one additional dynamically controllable electrode electrically connectable to the electric field generator.

19. The system of claim 13 wherein the at least one electrode is configured for monopolar use in conjunction with a separate external patient ground.

20. The system of claim 13 wherein the lumen is a guidewire lumen.

21. A method for performing renal neuromodulation, the method comprising:

intravascularly positioning a catheter within a renal blood vessel and at least partially adjacent to a renal nerve of a human patient, wherein the catheter comprises a distal balloon with a helical conductor arranged thereon;

expanding the distal balloon of the catheter;

delivering an energy field via the helical conductor to modulate neural function of the renal nerve; and

infusing one or more agents into the renal blood vessel before, during or after delivering the energy field, wherein the balloon comprises a weeping balloon and the one or more agents are infused therefrom.

22. The method of claim 21 wherein delivering an energy field via the helical conductor comprises delivering a non-pulsed thermal RF field.

23. The method of claim 21 wherein delivering an energy field via the helical conductor comprises delivering a bipolar electric field between at least one pair of electrodes arranged about the balloon.

24. The method of claim 21, further comprising monitoring at least one physiological parameter of the patient with a Doppler ultrasound sensor, a temperature sensor, a pressure sensor, an impedance detector, or a combination thereof.

25. The method of claim 21 wherein intravascularly positioning the catheter comprises delivering the catheter over a guidewire.

26. The method of claim 21 wherein infusing one or more agents into the renal blood vessel comprises infusing saline through one or more pores in the balloon.

27. The method of claim 21 wherein expanding the distal balloon comprises placing the helical conductor arranged on the balloon into physical contact with an inner wall of a renal blood vessel of the patient.

28. The method of claim 21 wherein intravascularly positioning the catheter comprises delivering the catheter via a sheath.