Medical instruments and techniques for thermally-mediated therapies

Patent metadata

Field	Value
Publication number	US-9433457-B2
Application number	US-71980810-A
Country	US
Kind code	B2
Filing date	Mar 8, 2010
Priority date	Dec 9, 2000
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A surgical instrument for thermally-mediated therapies in targeted tissue volumes and for causing thermal effects in polymer tissue-contacting members. In one embodiment, the instrument has a working end with an interior chamber that is supplied with a biocompatible liquid. An energy source causes a liquid-to-vapor phase change within the interior of the instrument. The vapor phase media then is ejected from the working surface of the instrument, and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. The vapor-to-liquid phase transitions, or internal energy releases, can be provided about thin-film flexible structures for engaging body lumens and cavities. An exemplary embodiment can be used for shrinking, sealing, welding or creating lesions in tissue—while causing limited collateral thermal damage and while totally eliminating electrical current flow in the engaged tissue.

First claim

I claim:

1. A method for a thermally-mediated therapy for treating tissue, the method comprising
providing an instrument having a selected media in a liquid form;
applying energy to the selected media such that the selected media increases in volume causing a liquid-to-vapor phase transition of the selected media to a vapor form;
delivering a pressurized vapor stream of the selected media to flow from the instrument while controlling a pressure of the pressurized vapor stream; and
directing the pressurized vapor stream of the selected media to a tissue site such that contact with the tissue site causes a vapor-to-liquid phase state change of the pressurized vapor stream to the liquid form and where the vapor-to-liquid phase state change releases a thermal energy substantially equal to a heat of vaporization of the selected media to the tissue site to cause ablation of the tissue site.

2. The method for the thermally-mediated therapy of claim 1 wherein the heat of vaporization is in excess of about 500 calories per gram of the selected media.

3. The method for the thermally-mediated therapy of claim 1 wherein the vapor-to-liquid phase state change is created within a patient's body after pressurized ejection of the selected media from at least one port of the instrument.

4. The method for the thermally-mediated therapy of claim 1 wherein the vapor-to-liquid phase state change is created at a selected depth in tissue after pressurized ejection of the media from the instrument.

5. The method for the thermally-mediated therapy of claim 1 wherein the vapor-to-liquid phase state change is created about a flexible working surface deployed in the interior of a body cavity or lumen.

6. The method for the thermally-mediated therapy of claim 1 further comprising the step of controlling a parameter when applying energy to the media, the parameter being selected from a class of parameters consisting of controlling the temperature of the vapor-to-liquid phase state change in the selected media, controlling a volume of the selected media flowing from the instrument, and controlling the rate of delivery of the selected media volume flowing from the instrument.

7. The method for the thermally-mediated therapy of claim 1 wherein the vapor media reduces in volume during the vapor-to-liquid phase state change.

8. The method for the thermally-mediated therapy of claim 1 wherein the vapor-to-liquid phase state change applies thermal energy capable of at least one of shrinking, sealing, welding and creating lesions in tissue.

9. The method for the thermally-mediated therapy of claim 1 wherein the media in the vapor form has a temperature of at least 100° C.

10. The method for the thermally-mediated therapy of claim 1 including controlling at least one of the pressure of the selected media in the vapor form, the volume of the selected media in the vapor form, and a duration of the pressurized vapor stream.

11. The method for the thermally-mediated therapy of claim 5 where directing the pressurized vapor stream of the selected media comprises directing the pressurized vapor stream through an expandable member by engaging the expandable member against the tissue.

Assignees

• Shadduck John H
• Tsunami Medtech Llc

Inventors

• Shadduck John H

Classifications

• A61B18/04 Primary

  by heating (by applying electromagnetic radiation A61B18/18) · CPC title

• A61B2018/0022

  Balloons · CPC title

• A61B2018/00619

  Welding · CPC title

• A61B2018/00404

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

• A61B2090/064

  for measuring force, pressure or mechanical tension · CPC title