Method and system for photoselective vaporization for gynecological treatments

Abstract

A method for photoselective vaporization of uterine tissue includes delivering laser radiation to the treatment area on the tissue, via an optical fiber for example, wherein the laser radiation has a wavelength and irradiance in the treatment area on the surface of the tissue sufficient because vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation. The laser radiation is generated using a neodymium doped solid-state laser, including optics producing a second or higher harmonic output with greater than 60 watts average output power. The delivered laser radiation has a wavelength for example in a range of about 200 nm to about 650 nm, and has an average irradiance in the treatment area greater than about 10 kilowatts / cm2, in a spot size of at least 0.05 mm2.

Description

RELATED APPLICATION INFORMATION [0001] The present application is a continuation of U.S. patent application Ser. No. 10 / 371,080 filed 21 Feb. 2003, which application claims the benefit of U.S. Provisional Application No. 60 / 358,356, filed 22 Feb. 2002. [0002] The present application is related to U.S. patent application Ser. No. 10 / 278,723, filed 23 Oct. 2002. [0003] The present application is related to U.S. patent application Ser. No. 09 / 737,721, filed 15 Dec. 2000, now U.S. Pat. No. 6,554,824. [0004] The present application is related to U.S. patent application Ser. No. 10 / 279,087, filed 23 Oct. 2002.BACKGROUND OF THE INVENTION [0005] 1. Field of the Invention [0006] The present invention relates generally to laser treatment of tissue, and more particularly to photoselective vaporization of tissue, including uterine tissue, as applied to the treatment of gynecological conditions. [0007] 2. Description of Related Art [0008] A commonly employed procedure for removal of tissue in th...

AI Technical Summary

Benefits of technology

[0018] The present invention provides a method for treating gynecologic conditions, including conditions involving uterine tissue, such as intramural and intracavitery uterine myomas, leiomyoma uteri, rhabdomyoma, endometriosis, endometrial hyperplasia, endometrial cysts, endometrial polyps, menorrhagia, uterine septa, intrauterine adhesions, or cervical intraepithelial neoplasia. Other gynecological conditions involving the female reproductive organs such as the fallopian tubes, the ovaries, and the vagina, are also treatable according to the present invention. Treatment according to the embodiments of present invention is executed by vaporizing, incising, or coagulating tissue, such as uterine tissue, using a laser that generates light with an average power greater than 40 watts and a wavelength between 300 and 700 nm where the output beam of the laser is delivered to the target tissue through an optical waveguide, such as an optical fiber that emits light in forward direction (end-firing) or in a laterally directed manner (side-firing) where laterally means at an angle of 10°-170° with respect to the fiber axis, and where the waveguide is guided into the vagina or the uterine cavity using a hysteroscope. In embodiments of the invention, the hysteroscope is equipped with a rigid tip. In other embodiments of the invention, the hysteroscope is equipped with a flexible tip, which can be manipulated by the surgeon, allowing greater control over the procedure, and access to more regions of the target tissue.

[0031] Furthermore, embodiments of the invention include the delivery of the laser energy using a Q-switched, solid-state laser which produces micro-pulses in combination with applying pump power to the laser medium in a sequence a pulses so that output radiation is produced in macro-pulses having a peak power of greater than 200 watts, and more preferably about 240 watts or greater. The peak irradiance in the treatment area during the pulses is thereby substantially increased, and preferably greater than 50 kilowatts / cm2, and as much as 90 kilowatts / cm2 in some embodiments of the invention.

Problems solved by technology

Although 1064 nm light is hemostatic at high power levels, its low absorption in blood and uterine tissue leads to inefficient ablation and a large residual layer of thermally denatured tissue several millimeters thick.

The difficulty of achieving higher average output power densities is that when high input powers are supplied to the laser element from an excitation source such as an arclamp a large amount of heat is generated in the lasing element.

This heat induces various deleterious effects in the lasing element.

In particular the temperature difference between the coolant and the hot lasing element generates a thermally induced graded index lens that decreases the beam quality of the laser and causes the laser to operate with more transverse optical modes than it would otherwise.

The larger number of modes makes M2 larger and makes it difficult to focus the light into small, low numerical aperture fibers and reduces the ability to project high power density light onto tissue.

As a result, the vaporization efficiency of CW arclamp pumped 532 nm lasers is significantly reduced.

Surgical procedures within the uterus have unique risks.

Any surgery in the uterus must avoid weakening of the wall of the uterus, which could lead to complications during pregnancy.

Also, the physiological diversity of the uterus increases the difficulty of intrauterine operations.

In case of a myoma in the cornu, the uterine wall is further thinned by the myoma, which increases the risk of intraoperative perforation of the uterine wall.

Even if perforation does not occur, the presence of a thin uterine wall could predispose the patient to bowel injury.

As stated by Indman, J. Reproduct. Med. 1991, lack of precise knowledge of the minimum thickness of the uterine wall may be the limiting factor in determining the safety of use of the 1064 nm Nd:YAG laser for endometrial ablation.

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