Methods for monitoring renal neuromodulation

• US 8,768,470 B2
• Filed: 05/11/2010
• Issued: 07/01/2014
• Est. Priority Date: 04/08/2002
• Status: Expired due to Fees

• 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:
  US12/777,892
• Publication Number:
  US 20100222851A1
• Time in Patent Office: 1,512 Days
• Field of Search: 607/2, 607/3, 607/44, 607/62, 607/117, 607/118, 604/891.1, 600/504, 600/554
• US Class Current: 607/44
• 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 reversible electroporation A61N1/327
• 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. A method for monitoring renal neuromodulation, the method comprising:

applying a stimulation electric field to a tissue;

monitoring a physiologic response to the stimulation electric field indicating in the tissue the presence of a neural fiber that innervates a kidney; and

inhibiting neural activity along the neural fiber in a minimally invasive manner,

wherein inhibiting neural activity along the neural fiber comprises applying a denervating electric field to the neural fiber via an intravascularly positioned catheter.

2. The method of claim 1 wherein applying a stimulation field and monitoring a physiologic response comprise applying a stimulation field and monitoring a first physiologic response prior to applying a denervating electric field and applying a stimulation field and monitoring a second physiologic response after applying a denervating electric field.

3. The method of claim 2 further comprising comparing the first physiologic response and the second physiologic response to determine an extent of renal neuromodulation.

4. The method of claim 1 wherein applying a denervating electric field comprises ablating the neural fiber.

5. The method of claim 1 wherein applying a stimulation electric field comprises stimulating afferent renal nerve fibers.

6. The method of claim 1 wherein applying a stimulation electric field comprises stimulating efferent renal nerve fibers.

7. The method of claim 1 wherein applying a stimulation electric field comprises intravascularly delivering the stimulation electric field.

8. The method of claim 7 wherein applying a stimulation electric field further comprises modulating at least one of frequency, amplitude and pulse duration of the stimulation electric field to facilitate passage of the electric field to the tissue.

9. The method of claim 1 wherein monitoring a physiologic response to the stimulation electric field comprises monitoring at least one of renin, sodium, and blood pressure.

10. The method of claim 1 wherein monitoring a physiologic response to the stimulation electric field comprises monitoring a reduction in renal blood flow.

11. The method of claim 1, further comprising identifying an optimal location for renal neuromodulation based on the monitored physiologic parameter.

12. The method of claim 1 wherein the stimulation field is a first stimulation field, and wherein the method further comprises applying a second stimulation field to the tissue and monitoring the absence of a physiologic response following inhibiting neural activity along the neural fiber.

13. A method for monitoring effectiveness of renal neuromodulation, the method comprising:

applying a stimulation electric field to renal nerves;

monitoring a change in renal blood flow in response to the stimulation electric field; and

delivering an energy field to the renal nerves via an intravascularly positioned catheter, wherein the energy field inhibits neural activity along the renal nerves.

14. The method of claim 13 wherein monitoring a change in renal blood flow comprises monitoring the velocity of blood flow through the renal artery.

15. The method of claim 14 wherein monitoring the velocity of blood flow through the renal artery comprises monitoring blood flow velocity using a Doppler ultrasound sensor.

16. The method of claim 13 wherein monitoring a change in renal blood flow comprises monitoring the flowrate of blood flow through the renal artery.

17. The method of claim 16 wherein monitoring a change in renal blood flow further comprises monitoring the flowrate prior to stimulation to determine a baseline flowrate, monitoring the flowrate after stimulation and comparing the flowrate after stimulation to the baseline flowrate.

18. The method of claim 13 wherein monitoring a change in renal blood flow comprises visually monitoring a change in renal blood flow.

19. The method of claim 18 wherein visually monitoring a change in renal blood flow comprises visualizing renal blood flow using an external ultrasound transducer.

20. The method of claim 13 wherein monitoring a change in renal blood flow comprises monitoring renal blood flow via a pressure transducer.

21. The method of claim 13 wherein monitoring a change in renal blood flow comprises measuring travel time lag of an intravascular temperature input.

22. The method of claim 13 wherein delivering an energy field to the renal nerves comprises ablating the renal nerves via the energy field.