System and method for mapping the functional nerves innervating the wall of arteries, 3-D mapping and catheters for same

• US 9,820,811 B2
• Filed: 12/01/2015
• Issued: 11/21/2017
• Est. Priority Date: 08/26/2011
• Status: Active Grant

• Current Assignee: Symap Medical suzhou Ltd
• Original Assignee: Symap Medical suzhou Ltd
• Inventors: Wang, Jie
• Primary Examiner(s): CAREY, MICHAEL JAMES
• Application Number:
  US14/956,350
• Publication Number:
  US 20160081744A1
• Time in Patent Office: 721 Days
• Field of Search: 607118, 607117, 607148, 607149, 607 44, 606 20, 606 27, 606 32
• 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 2018/00202 rotating
• 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 2018/00511 Kidney
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/1435 Spiral
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 5/0036 including treatment, e.g., using an implantable medical device, ablating, ventilating
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/201 Assessing renal or kidney functions
• CPC Class Codes: A61B 5/24 : Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/4833 : Assessment of subject's compliance to treatment
• CPC Class Codes: A61B 5/4893 : Nerves
• CPC Class Codes: A61B 5/6852 : Catheters
• CPC Class Codes: A61B 5/6853 : with a balloon
• CPC Class Codes: A61B 5/7246 : using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61N 1/056 : Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/36117 : for treating hypertension

Abstract

Disclosed herein are systems and methods for locating and identifying nerves innervating the wall of arteries such as the renal artery. The present invention identifies areas on vessel walls that are innervated with nerves; provides indication on whether energy is delivered accurately to a targeted nerve; and provides immediate post-procedural assessment of the effect of energy delivered to the nerve. The methods includes evaluating a change in physiological parameters after energy is delivered to an arterial wall; and determining the type of nerve that the energy was directed to (sympathetic or parasympathetic or none) based on the evaluated results. The system includes at least a device for delivering energy to the wall of blood vessel; sensors for detecting physiological signals from a subject; and indicators to display results obtained using said method. Also provided are catheters for performing the mapping and ablating functions.

Claims

1. A proximal renal ablation method for ablation of sympathetic renal nerve of a subject, comprising the steps of:

a) introducing a catheter into the lumen of a renal artery such that the tip of said catheter contacts a site on an inner wall of said renal artery, wherein said site is within a proximal region from an ostium of said renal artery, wherein said proximal region has a length equals to one-third of total length of said renal artery;

b) applying electrical stimulation by introducing electrical current to said site via the catheter, wherein said electrical current is controlled to be sufficient to elicit changes in one or more physiological parameters when there is an underlying nerve at said site, said one or more physiological parameters are selected from the group consisting of systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate;

c) measuring said one or more physiological parameters after said electrical stimulation, wherein an increase of said one or more physiological parameters as compared to measurements obtained before said electrical stimulation would indicate that a sympathetic renal nerve has been mapped at said site; and

d) applying ablation energy through the catheter to the site identified in step (c) for ablation of said sympathetic renal nerve.

2. The method of claim 1, wherein said catheter is an ablative catheter currently in use to treat cardiac arrhythmias.

3. The method of claim 1, wherein said catheter is an ablative catheter designed specifically for mapping renal nerves for ablative procedures.

4. The method of claim 1, further comprises repeating the steps (b) to (c) on the site identified in (c), wherein a lack of change in said one or more physiological parameters confirms nerve ablation.

5. The method of claim 1, wherein said electrical current has one or more of the following parameters:

(a) voltage between 2 and 30 volts;

(b) resistance between 100 and 1000 ohms;

(c) current between 5 and 40 milliamperes;

(d) time of application between 0.1 and 20 milliseconds; and

(e) total applied time between 1 to 5 minutes.

6. A proximal renal ablation method for ablation of renal nerve of a subject, comprising the steps of:

a. determining the presence of a renal nerve by

i. contacting a first site on an inner wall of a renal artery with one or more first electrodes, said first site is in a proximal region from an ostium of said renal artery, wherein said proximal region has a length equals to one-third of total length of said renal artery;

ii. applying a first electrical stimulation by introducing electrical current to said first site via said first electrodes, wherein said electrical current is controlled to be sufficient to elicit changes in one or more physiological parameters when there is an underlying nerve at said first site, said one or more physiological parameters are selected from the group consisting of systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate; and

iii. measuring said one or more physiological parameters after said first electrical stimulation, wherein an increase of said physiological parameters as compared to measurements obtained before said first electrical stimulation would indicate the presence of a sympathetic renal nerve;

b. contacting a second site on an inner wall of said renal artery with one or more second electrodes, said second site is within a proximal region from an ostium of said renal artery, wherein said proximal region has a length equals to one-third of total length of said renal artery;

c. delivering ablation energy to said second site via said second electrodes; and

d. applying a second electrical stimulation to said first site via said first electrodes and measuring said physiological parameters after applying said ablation energy, wherein no increase of said physiological parameters after said second electrical stimulation indicates ablation of said sympathetic renal nerve in said subject.

7. The method of claim 6, further comprising repetition of steps (b) to (d) at a new second site if ablation at an original second site did not ablate the renal nerve in said subject.

8. The method of claim 6, wherein said first electrodes and second electrodes are located on a single catheter.

9. The method of claim 6, wherein said first electrodes and second electrodes are located on different catheters.

10. The method of claim 6, wherein said electrical current has one or more of the following parameters:

(a) voltage between 2 and 30 volts;

(b) resistance between 100 and 1000 ohms;

(c) current between 5 and 40 milliamperes;

(d) time of application between 0.1 and 20 milliseconds; and

(e) total applied time between 1 to 5 minutes.

11. The method of claim 6, wherein said first electrodes or second electrodes are located on a catheter comprising an expandable tip at its distal end.

12. The method of claim 11, wherein said expandable tip when viewed from the distal end has a diameter in the range of 3.5 mm to 20 mm.

13. The method of claim 11, wherein said expandable tip comprises a tubular structure that houses one or more resilient members with pre-formed curvatures, wherein said first or second electrodes are disposed on said one or more resilient members, said one or more resilient members are attached at their proximal ends to a controlling shaft, wherein movement of said controlling shaft causes said one or more resilient members to be pushed out of said tubular structure to resume the pre-formed curvature or retracted into said tubular structure.

14. The method of claim 6, wherein said first or second electrodes are disposed on a section of a catheter having a configuration comprising a spiral having one or more loops.

15. The method of claim 14, wherein said configuration comprises a spiral pyramid with loops becoming progressively smaller from a proximal end to a distal end.