VISUAL ELECTRODE ABLATION SYSTEMS

• US 20090227999A1
• Filed: 05/14/2009
• Published: 09/10/2009
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Voyage Medical, Inc.
• Inventors: Saadat, Vahid, Miller, David, Willis, N. Parker, Malchano, Zachary J., Rothe, Chris A., Tam, Edmund, Peh, Ruey-Feng
• Granted Patent: US 9,155,587 B2
• Time in Patent Office: Days
• US Class Current: 606/14
• CPC Class Codes: A61B 1/00089 Hoods
• CPC Class Codes: A61B 1/012 characterised by internal passages or accessories 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 2017/00106 ultrasonic
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00809 measured thermochromatically
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

Visual electrode ablation systems are described herein which include a deployment catheter and an attached imaging hood deployable into an expanded configuration. In use, the imaging hood is placed against or adjacent to a region of tissue to be imaged in a body lumen that is normally filled with an opaque bodily fluid such as blood. A translucent or transparent fluid, such as saline, can be pumped into the imaging hood until the fluid displaces any blood, thereby leaving a clear region of tissue to be imaged via an imaging element in the deployment catheter. An electric current may be passed through the fluid such that it passes directly to the tissue region being imaged and the electrical energy is conducted through the fluid without the need for a separate ablation probe or instrument to ablate the tissue being viewed.

Claims

1. A tissue ablation apparatus, comprising:

a barrier or membrane projecting from a deployment catheter and defining a field when the barrier or membrane is expanded from an insertion configuration to a deployed configuration which defines at least one aperture through which fluid is permeable,

an energy source spaced from the aperture such that energy from the energy source passes through a purging fluid introduced into the field and into a tissue surface when adjacent to the aperture, and

wherein introduction of the purging fluid displaces blood from the field such that the tissue surface is temporarily isolated from a surrounding blood-filled environment by the barrier or membrane whereby a lesion is formed by the energy passed into the tissue surface.

2. The apparatus of claim 1 wherein the lesion defines a pattern when formed within the temporarily isolated field.

3. The apparatus of claim 2 wherein the pattern is consistently repeatable over the tissue surface.

4. The apparatus of claim 1 wherein the barrier or membrane defines a conical structure.

5. The apparatus of claim 1 wherein the purging fluid comprises saline.

6. The apparatus of claim 1 wherein the barrier or membrane comprises a distal membrane along which the aperture is defined.

7. The apparatus of claim 1 further comprising an imaging element positioned within or along the barrier or membrane and adapted to image the tissue surface adjacent to the barrier or membrane when the field is purged of blood via the purging fluid.

8. The apparatus of claim 1 wherein the energy source comprises an electrode configured to conduct electrical energy through the purging fluid.

9. The apparatus of claim 1 wherein the energy source comprises laser energy or thermal energy.

10. The apparatus of claim 1 wherein the energy source is positioned within the barrier or membrane proximally of the field.

11. The apparatus of claim 1 wherein the energy source is configured as a support strut positioned along the barrier or membrane.

12. The apparatus of claim 1 wherein the energy source is configured as a ring electrode extending from a support member positioned within the field proximally of the aperture.

13. The apparatus of claim 1 further comprising one or more ultrasound transducers along an outer surface of the barrier or membrane for contacting the tissue surface.

14. A method of ablating a tissue surface, comprising:

positioning a barrier or membrane projecting from a deployment catheter and expanded from an insertion configuration to a deployed configuration against the tissue surface, the barrier or membrane defining at least one aperture through which fluid is permeable;

introducing a purging fluid into a field defined by the expanded barrier or membrane such that blood is displaced from the field and the tissue surface is temporarily isolated from a blood-filled environment; and

transmitting energy through the purging fluid and into the tissue surface such that a lesion is formed.

15. The method of claim 14 wherein positioning comprises placing the aperture against the tissue surface such that the field is isolated from the blood filled environment.

16. The method of claim 14 wherein positioning comprises intravascularly advancing the barrier or membrane into a chamber of a heart.

17. The method of claim 14 further comprising visualizing the tissue surface via an imager positioned within or along the barrier or membrane.

18. The method of claim 17 further comprising monitoring a change in color of the tissue surface whereby a blanched color is indicative of lesion formation.

19. The method of claim 17 further comprising monitoring the tissue surface for formation of bubbles.

20. The method of claim 17 further comprising adjusting a power level of the energy based upon visual images of the tissue surface.

21. The method of claim 17 wherein visualizing comprises inspecting the tissue region for discontinuous lesion formations.

22. The method of claim 14 further comprising repositioning the barrier or membrane to a second region of the tissue surface.

23. The method of claim 22 further comprising forming at least one additional lesion which is consistent with the lesion.

24. The method of claim 14 wherein transmitting comprises conducting electrical energy through the purging fluid.