Methods, systems, and apparatuses for protecting esophageal tissue during ablation

• US 20080161890A1
• Filed: 01/03/2007
• Published: 07/03/2008
• Est. Priority Date: 01/03/2007
• Status: Abandoned Application

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Lafontaine, Daniel M.
• Application Number:
  US11/649,009
• Publication Number:
  US 20080161890A1
• Time in Patent Office: Days
• US Class Current: 607/105
• 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 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00035 with return means
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00261 arranged in a line
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00

Abstract

The present disclosure is directed towards methods, systems, and apparatus for protecting esophageal tissue during ablation. An ablation system can include an esophageal catheter having a heat sink and an ablation catheter having at least one ablation element to deliver ablation energy, where heat generated by the ablation energy is absorbed by the heat sink.

Claims

1. An ablation system, comprising:

an esophageal catheter having a heat sink; and

an ablation catheter having at least one ablation element to deliver ablation energy, where heat generated by the ablation energy is absorbed by the heat sink.

2. The ablation system of claim 1, where the esophageal catheter includes:

an inner catheter tube defining a central conduit to receive a guidewire;

an elongate inner sleeve surrounding at least a portion of the inner catheter tube, where the inner sleeve is at least partially sealed at a distal end to an outer surface of the inner catheter tube to create an intermediate lumen; and

an elongate outer sleeve sealed to the outer surface of the inner catheter tube at a point distal from the distal end of the inner sleeve to create an outer lumen, where heat transfer fluid can move through the intermediate lumen and the outer lumen to absorb heat generated by the ablation catheter.

3. The ablation system of claim 1, where the esophageal catheter includes:

an elongate member having a proximal end and a distal end, an inflation lumen, an intake lumen, and an outtake lumen;

a balloon positioned around a portion of the elongate member and in fluid communication with the inflation lumen; and

a chamber disposed within the balloon and in fluid communication with the intake lumen and the outtake lumen, where coolant fluid can move through the intake lumen into the chamber and through the outtake lumen to absorb heat generated by the ablation catheter.

4. The ablation system of claim 1, where the esophageal catheter includes:

an elongate member having a proximal end and a distal end, an inlet lumen, an exhaust lumen, and an inflation lumen;

a first balloon and a second balloon positioned around separate portions of the elongate member, where the inflation lumen is in fluid communication with the first balloon and the second balloon, the inlet lumen extends to an exterior surface of the elongate member at a first point proximal the first balloon, and the exhaust lumen extends to the exterior surface of the elongate member at a second point distal the second balloon, where a heat transfer fluid can flow through the inlet lumen to the exterior surface of the elongate member at the first point, outside the exterior surface of the elongate member to the second point, and through the exterior surface of the elongate member through the exhaust lumen to absorb heat generated by the ablation catheter.

5. The ablation system of claim 1, where the esophageal catheter includes:

an elongate member adapted to be slidably disposed about a core wire;

a cryo tube disposed adjacent to the elongate member, the cryo tube having a proximal region and a distal region including a coil disposed about at least a portion of the elongate member, where the coil includes at least one opening;

an outer tube disposed over at least a portion of the cryo tube; and

a cooling member disposed over the coil and coupled to the outer tube.

6. The ablation system of claim 1, where the esophageal catheter includes:

an elongate member with a proximal end and a distal end, and an inside surface adjacent the distal end;

a thermoelectric cooling device coupled to the inside surface of the elongate member;

an inner catheter tube inside the elongate member, where the inner catheter defines a central conduit extending from the proximal end to the distal end of the elongate member;

an intermediate sleeve that extends inside the elongate member from the proximal end to the distal end of the elongate member and seals to the inside surface of the elongate member and a point distal the thermoelectric cooling device.

7. The ablation system of claim 6, where heat transfer fluid can move through the central conduit toward the distal end of the elongate member, and can return toward the proximal end through an intermediate lumen defined by an outside surface of the inner catheter tube and an inside surface of the intermediate sleeve.

8. The ablation system of claim 1, where the esophageal catheter includes at least one positioning member, where the positioning member has no column strength.

9. The ablation system of claim 8, where at least one positioning member is a string.

11. The ablation system of claim 1, where the esophageal catheter includes:

a trans-esophageal echocardiogram probe; and

a cooling jacket that surrounds at least a part of an outside surface of the esophageal echocardiogram probe.

12. The ablation system of claim 1, where the esophageal catheter includes a thermocouple adjacent the heat sink, where the thermocouple provides signals to change the heat sinks ability to absorb heat.

13. The ablation system of claim 1, where the esophageal catheter includes an inflatable member coupled to the esophageal catheter, where the inflatable member can hold the esophageal catheter in a predetermined position.

10. The ablation system of claim 10, where the heat sink and the at least one positioning member are formed from a biodegradable substance.

14. A method of protecting esophageal tissue, comprising:

applying ablation energy to a cardiac tissue site; and

removing heat from esophageal tissue to maintain a predetermined temperature of the esophageal tissue during the application of ablation energy

15. The method of claim 14, where maintaining the temperature of the esophageal tissue includes removing thermal energy from esophageal tissue heated as a result of applying the ablation energy.

16. The method of claim 15, where removing thermal energy from the esophageal tissue includes:

positioning a heat exchanger catheter into an esophagus; and

circulating a heat exchange fluid through the heat exchanger catheter to remove thermal energy from the esophageal tissue.

17. The method of claim 16, where removing thermal energy from the esophageal tissue includes:

positioning a trans-esophageal echocardial probe with a cooling jacket into an esophagus; and

circulating a heat exchange fluid through the cooling jacket to remove thermal energy from the esophageal tissue.

18. The method of claim 15, where removing thermal energy from the esophageal tissue includes positioning a heat sink in an esophagus.

19. The method of claim 14, where maintaining a temperature of esophageal tissue includes moving at least a portion of the esophageal tissue a distance away from the cardiac tissue site.

20. The method of claim 19, where moving at least a portion of the esophageal tissue includes:

locating the esophagus;

inserting an esophageal catheter into the esophagus; and

manipulating the esophageal catheter to move the esophagus a distance away from the cardiac tissue site.

21. The method of claim 20, where manipulating the esophageal catheter includes applying a magnetic field to the esophageal catheter to move the esophageal tissue.

22. The method of claim 14, where maintaining a temperature of the esophageal tissue includes:

inserting an electrical impedance detector into an esophagus;

detecting an impedance of a radio frequency ablation energy directed towards the cardiac tissue site; and

stopping the generation of ablation energy when the impedance detected reaches a predetermined lower limit.

23. A transesophageal echocardiogram probe, comprising:

an elongate member;

an ultrasonic transducer coupled to the elongate member, the ultrasonic transducer having a conductor to allow ultrasound signals to be sent and received from the probe;

a heat sink that surrounds at least a part of the elongate member to remove thermal energy.

24. The transesophageal echocardiogram probe of claim 23, where the heat sink includes:

an elongate inner sleeve surrounding at least a portion of an inner catheter tube;

an intermediate lumen defined by an outside surface of the inner catheter tube and an inside surface of the elongate inner sleeve; and

an elongate outer sleeve sealed at a distal end to the outer surface of the inner catheter tube at a point proximal the ultrasonic transducer, where heat transfer fluid can move through the inner catheter tube and the intermediate lumen to absorb heat.

25. The transesophageal echocardiogram probe of claim 24, where the heat sink includes:

a balloon positioned around a portion of the elongate member and in fluid communication with a fluid inlet lumen defined by the elongate member extending from the proximal end of the elongate member to a proximal end of the balloon; and

a fluid outlet lumen defined by the elongate member extending from a distal end of the balloon to the proximal end of the elongate member, where heat transfer fluid can move through the fluid inlet lumen into the balloon and through the fluid outlet lumen to absorb heat.

26. The transesophageal echocardiogram probe of claim 24, where the heat sink includes a first balloon and a second balloon positioned around separate portions of the elongate member, where an inflation lumen is in fluid communication with the first balloon and the second balloon, an inlet lumen extends to an exterior surface of the elongate member at a first point proximal the first balloon, and an exhaust lumen extends to the exterior surface of the elongate member at a second point distal the second balloon, where a heat transfer fluid can move through the inlet lumen to the exterior surface of the elongate member at the first point, outside the exterior surface of the elongate member to the second point, and through the exterior surface of the elongate member through the exhaust lumen to absorb heat generated by the ablation catheter.

27. The transesophageal echocardiogram probe of claim 24, where the heat sink includes:

a thermo-electric cooling device coupled to an inside surface of at least a portion of the elongate member;

an inner catheter tube defining a central conduit for receiving a cable to control the movement of the elongate member;

an elongate inner sleeve surrounding at least a portion of a length of the elongate member at least partially sealed at a distal end to an outer surface of the inner catheter tube creating an intermediate lumen;

an elongate inner sleeve sealed at a distal end to an inner surface of the elongate member at a point distal the thermoelectric cooling device to create an outer lumen, where the inner sleeve is in fluid communication with a heat transfer fluid source.