Apparatus for effective ablation and nerve sensing associated with denervation

Patent metadata

Field	Value
Publication number	US-10420481-B2
Application number	US-201816034854-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Oct 25, 2013
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

An intravascular catheter for nerve activity ablation and/or sensing includes one or more needles advanced through supported guide tubes (needle guiding elements) which expand to contact the interior surface of the wall of the renal artery or other vessel of a human body allowing the needles to be advanced though the vessel wall into the extra-luminal tissue including the media, adventitia and periadvential space. The catheter also includes structures which provide radial and lateral support to the guide tubes so that the guide tubes open uniformly and maintain their position against the interior surface of the vessel wall as the sharpened needles are advanced to penetrate into the vessel wall. Electrodes near the distal ends of the needles allow sensing of nerve activity before and after attempted renal denervation. In a combination embodiment ablative energy or fluid is delivered from the needles in or near the adventitia to ablate nerves outside of the media while sparing nerves within the media.

First claim

What is claimed is:

1. A method of modulating nerve activity, comprising:
positioning a distal portion of a catheter within a renal vessel;
advancing a first needle guiding element and a second needle guiding element outward from the catheter toward an inside surface of the renal vessel;
advancing a first needle and a second needle through the first needle guiding element and second needle guiding element, respectively, and into a peri-vascular space outside of the inside surface of the renal vessel, wherein a distal end of the first needle guiding element and a distal end of the second needle guiding element are configured to maintain their position against the inside surface of the renal vessel as the first needle and the second needle advance into the peri-vascular space; and
operating the catheter to provide at least one modality of neurolysis to nerves located in the peri-vascular space or to sense nerve activity from at least one of the first and second needles.

2. The method as in claim 1 , wherein the at least one modality of neurolysis includes injecting an ablative fluid through the first needle and the second needle to form two ablative fluid zones in the peri-vascular space.

3. The method as in claim 2 , wherein the ablative fluid injected from each needle into the peri-vascular space travels circumferentially forming one zone for each needle where the zones approximately intersect to form a ring of neurolysis.

4. The method as in claim 2 , wherein injecting the ablative fluid comprises injecting ethanol.

5. The method as in claim 1 , wherein the at least one modality of neurolysis includes providing ablation of nerves using energy delivered by at least the first needle.

6. The method as in claim 5 , where the energy delivered is in the radiofrequency spectrum.

7. The method as in claim 5 , where the energy delivered includes providing ultrasonic ablation from an ultrasound transducer.

8. The method as in claim 1 , further including evaluating nerve activity by comparison to a treatment criterion.

9. The method as in claim 5 , wherein operating the catheter to sense nerve activity uses a return that is provided by at least one of: the second needle, an electrode on the skin of the patient, or an electrode on the catheter.

10. The method as in claim 1 , wherein operating the catheter to sense nerve activity includes sensing nerve activity during two or more periods of time separated by at least 30 seconds.

11. The method as in claim 10 , where the two or more periods of time include a first period of time before ablation and a second period of time after ablation.

12. The method as in claim 1 , wherein the catheter includes a third needle, wherein operating the catheter to sense nerve activity includes sensing nerve activity between the first needle and the second needle, between the first needle and the third needle, or between the second needle and the third needle.

13. The method as in claim 1 , including evaluating the quality of neurolysis by comparison of the nerve activity to a pre-set criterion.

14. The method as in claim 1 , wherein operating the catheter to sense nerve activity further includes sensing nerve activity between at least two needles.

15. A method of modulating nerve activity, comprising:
positioning a distal portion of a catheter within a vessel of a human patient;
advancing at least a first needle guiding element and a second needle guiding element outward from the catheter toward an interior wall of the vessel;
advancing at least a first needle and a second needle through the first guiding element and the second needle guiding element and into a peri-vascular region outside of the interior wall of the vessel, wherein a distal end of the first needle guiding element and a distal end of the second needle guiding element are configured to maintain their position against the interior wall of the vessel as the first needle and the second needle advance into the peri-vascular region;
wherein the catheter is configured to provide at least a first modality of neurolysis to nerves located in a peri-vascular region of the patient or sense nerve activity from at least one location in the peri-vascular region.

16. The method as in claim 15 , further including using external equipment to provide a measurement of nerve activity.

17. The method as in claim 16 , wherein the measurement of nerve activity is used to determine the efficacy of the first modality of neurolysis.

18. The method as in claim 17 , wherein at least part of the method is repeated if the level of neurolysis is insufficient.

19. The method as in claim 15 , where a second modality of neurolysis is applied, wherein the second modality of neurolysis is different from the first modality of neurolysis.

20. The method as in claim 16 , wherein a visual display is used to provide the measurement of the nerve activity.

21. The method as in claim 16 , wherein the measurement of nerve activity includes a measurement of one or more of:
spike count,
mean burst frequency,
peak burst frequency,
power within at least one spectral band, and
a normalized measurement of nerve activity which compares nerve activity after injection to nerve activity before injection.

Assignees

• Ablative Solutions Inc

Inventors

• Fischell David R
• Fischell Tim A
• Ghazarossian Vartan
• Almany Steven
• John Michael Sasha

Classifications

• A61B17/320068

  using mechanical vibrations, e.g. ultrasonic (A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745) · CPC title

• A61B2018/00404

  Blood vessels other than those in or around the heart · CPC title

• A61B2018/1432

  curved · CPC title

• A61B18/0218

  with open-end cryogenic probe, e.g. for spraying fluid directly on tissue or via a tissue-contacting porous tip · CPC title

• A61B5/6852

  Catheters · CPC title