Method for emitting therapeutic energy within tissue

• US 6,143,019 A
• Filed: 02/20/1998
• Issued: 11/07/2000
• Est. Priority Date: 08/22/1995
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Ware, David L., Motamedi, Massoud
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/026,590
• Time in Patent Office: 991 Days
• Field of Search: 607/88, 607/89, 607/92, 607/99-102, 607/105, 607/113, 607/122, 607/126, 606/14, 606/15, 606/33, 128/898
• US Class Current: 607/89
• CPC Class Codes: A61B 18/00 Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body eye surgery A61F9/007; ear surgery A61F11/00
• 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 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 2017/00053 Mapping
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00392 Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/2261 with scattering, diffusion or dispersion of light
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body

Abstract

A catheter capable of both sensing myocardial electrical activity and delivering ablating energy within myocardial tissue is disclosed. The catheter comprises electrodes on the outer sheath and contains a movable fiber optic cable that can be percutaneously advanced beyond the catheter body and into the myocardium for myocardial heating and coagulation, or modification of tissues responsible for cardiac arrhythmias. The fiber optic tip is designed to diffuse ablating energy radially to ablate a larger volume of tissue than is possible with a bare fiber optic tip. In addition, the tip is treated so that energy is not propagated in a forward direction, thus helping to prevent unwanted perforation of the heart tissue. Also disclosed is a method of cardioprotection from ischemia comprising inducing local hyperthermia in heart tissue.

Claims

1. A method of inducing angiogenesis comprising the steps of:

(a) positioning the distal end of a catheter proximate to the endocardium;

(b) identifying a target area of tissue;

(c) extending the distal end of a conductor through the distal end of the catheter and into the tissue; and

(d) transmitting energy through the conductor into the tissue to create volumetric hyperthermia in said tissue.

2. The method of claim 1, wherein the conductor comprises a wave guide and the energy comprises laser energy.

3. The method of claim 1, wherein said tissue reaches a temperature of at least about 40°

C.

4. The method of claim 1 wherein said energy is conductive energy.

5. A method of inhibiting tissue damage due to ischemia comprising providing radiative or conductive energy within said tissue in an amount effective to induce local volumetric hyperthermia.

6. The method of claim 5, wherein said tissue is heart tissue and said energy is applied beneath the endocardial surface, beneath the epicardial surface or within the interstitial area of said heart.

7. A method of inhibiting tissue damage due to insults including reperfusion injury, said method comprising providing radiative or conductive energy within said tissue in an amount effective to induce local volumetric hyperthermia.

8. The method of claim 7, wherein said tissue is heart tissue and said energy is applied beneath the endocardial surface, beneath the epicardial surface or within interstitial area of a heart.

9. The method of claim 7, wherein said tissue comprises an organ and the energy is applied in vivo or in vitro to said organ in order to extend the time for tissue transplant and/or to improve the outcome of organ transplant.

10. A method for the endogenous production of heat shock proteins (HSPs) or growth factors within tissue comprising:

delivering energy into the tissue to create volumetric hyperthermia in said tissue in an amount effective to stimulate the expression and release of HSPs or growth factors within the tissue.

11. The method of claim 10, wherein the tissue is cardiac tissue.

12. The method of claim 10, wherein HSP70 is produced in the tissue.

13. The method of claim 10, wherein vascular endothelial growth factor (VEGF) is produced in the tissue.

14. The method of claim 10, wherein the tissue is cardiac tissue and the energy is delivered by penetrating the endocardium and applying said energy to the myocardium.

15. The method of claim 10, wherein the energy is delivered interstitially.

16. The method of claim 10, wherein the tissue is heated to a temperature of greater than 40°

C.