US 20050228288 A1
The invention is a transvaginal ultrasound probe having an attached echogenic needle that is useful in the treatment of uterine fibroids. The echogenic needle has an echogenic surface near its tip that allows the physician to visualize its location using ultrasound imaging. In one embodiment, the needle has an active electrode at its distal end. The active electrode supplies radio frequency energy to a fibroids causing necrosis of the targeted fibroid or by destroying the fibroid's vascular supply. The radio frequency needle preferably has a safety device that shuts-off energy if the needle punctures the uterine wall. In a second embodiment, the needle has a cryogen supply tube and cryogen supply. This embodiment destroys fibroid tissue by freezing it or its vascular supply when the tissue comes in contact with the needle's frozen distal end. The invention further includes the method of using the ultrasound probe with the attached needle.
1. An echogenic medical needle comprising:
a tubular outer member having a distal end and proximal end, said tubular outer member being positionable into a needle guide that is attached to a vaginal ultrasonic probe;
an echogenic surface disposed proximal to said distal end;
a cryo-insulation sheath disposed on said outer tubular member and defining a distal segment of said outer member that is cryo-noninsulated so that said distal end can be placed in cryogenic contact with uterine fibroids; and
a cryogen supply tube extending from said proximal end to said distal end through which a cryogenic supply is provided to said distal end.
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8. An echogenic medical needle for transvaginal ultrasound directed cryoablation of uterine myomas and fibroids comprising:
a tubular outer member having an inner surface, a distal end having an echogenic surface, and a proximal end;
a cryo-insulation sheath surrounding a surface of a segment of said outer member, said cryo-insulated segment extending from said proximal end of said outer member to, but not including, said distal end of said outer member, such that said distal end can be placed in cryogenic contact with uterine fibroids;
a cryogen supply tube extending from said proximal end of said outer member to said distal end of said outer member; and
a vaginal ultrasonic probe having an attached needle guide whereby said medical needle is positionable in said needle guide.
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18. A method for the cryoablation of myomas and fibroids in the uterus using a transvaginal ultrasound directed echogenic medical needle comprising the steps of:
a) providing an ultrasound probe having a transducer and a needle guide attached to said probe;
b) providing an echogenic needle, the echogenic needle including a tubular outer member having a distal end having a echogenic surface, a proximal end, a cryo-insulation sheath surrounding a surface of a segment of said outer member, said cryo-insulated segment extending from said proximal end of said outer member to, but not including, said distal end of said outer member, a cryogen supply tube within said outer member, said tube extending from send proximal end of said outer member to said distal end of said outer member, and a cryogen supply that is in communication with said tube whereby said cryogen supply is delivered to said distal end of said outer member;
c) inserting said ultrasound probe into a uterus;
d) inserting said echogenic needle into said uterus through said needle guide;
e) sensing the location of said fibroids and said echogenic needle within said uterus with said ultrasonic probe;
f) guiding said echogenic needle to a surface of said fibroids using the ultrasound imaging;
g) positioning said echogenic needle on said surface of said fibroid; and
h) delivering a controlled amount of said cryogen supply to the surface of said myoma to cause cryoablation of said fibroid.
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This application is a divisional application of U.S. application Ser. No. 10/345,635, filed Jan. 16, 2003, which is hereby incorporated herein in its entirety by reference.
This invention relates to surgical needles for tissue ablation, and more particularly, to surgical needles that are for ablation of uterine fibroids.
Approximately 20 to 40 percent of women have uterine fibroids (lieomyomata). In the United States, fibroids result in approximately 175,000 hysterectomies and 20,000 myomectomies each year. Fibroids are well-defined, non-cancerous tumors that arise from the smooth muscle layer of the uterus. Approximately 25% of women suffer fibroid related symptoms, including menorrhagia (prolonged or heavy menstrual bleeding), pelvic pressure or pain, and reproductive dysfunction.
The most common treatments for fibroids include hysterectomy, abdominal myomectomy, laparoscopic myomectomy, hysteroscopic myomectomy, laparoscopy-directed needle mylosis, laparoscopy-directed needle cryomyolysis, high-intensity focused ultrasound ablation of fibroids, and uterine artery embolization. Hysterectomy is a major surgical procedure and carries with it the usual risk of surgery, such as hemorrhaging, lesions, complications, pain, and prolonged recovery. The majority of myomectomies are performed abdominally, wherein a surgeon creates an abdominal incision through which individual fibroids are removed. Abdominal myomectomy and laparoscopic myomectomy, like a hysterectomy, carries the usual risk of surgery.
Radio Frequency (RF) myolysis and thermal tissue ablation are two promising methods for treating fibroids. RF myolysis is a technique in which a RF probe is inserted into a fibroid or the surrounding tissue and then RF energy is applied to the tip of the probe. The tissue surrounding the tip is heated by the RF energy causing necrosis within the tissue. Thermal tissue ablation is a technique that is performed with a cryoablation probe. The cryoablation probe destroys the fibroid tissue by freezing it.
Current methods incorporating RF or cryoablation techniques require direct visualization of the needle tip or electronic imaging. Normally, under direct visualization techniques an endoscope is inserted into the uterus to position the needle. Direct visualization is often problematic because of the difficulties involved in simultaneously manipulating the endoscope and needle. Typically, when electronic imaging is used, the position of the needle is visualized with a hysteroscope or with an external abdominal ultrasound. Hysteroscopy allows direct visualization of the uterine cavity by inserting a small camera on the end of a long tube directly into the uterus through the vagina and cervix. Similar to an endoscope, a hysteroscope must be simultaneously manipulated with the needle, and thus is problematic. Monitoring the probe's position with current ultrasound techniques has a number of drawbacks. For example, a clinician using ultrasound imaging from an external source will have difficulty in distinguishing the uterine tissue from the surrounding organs and precisely locating the needle.
U.S. Pat. No. 5,979,453 to Savage et al. describes a myolysis needle that requires laparoscopic surgery. In laparoscopic surgery the needle must be placed through the uterine serosa into or near the fibroid. As a result, uterine adhesions often form that may cause chronic pain, infertility, and bowel obstruction. Additionally, during laparoscopic surgery the surgeon cannot visualize the tissue below the surface and must blindly place the needle, as a result placement may be sub-optimal.
U.S. Pat. No. 6,146,378 to Mikus et al. discloses a needle placement guide having an endoscope that is inserted into the uterus through the vagina. Using the endoscope, the surgeon positions the endoscopic guide in the correct orientation to the targeted fibroid. After positioning the guide, the endoscope is removed from within the guide and an ablation device is inserted into the guide for subsequent operation on the fibroid. The needle guide suffers from several disadvantages. There is the risk that the needle guide could shift during removal of the endoscope and insertion of the ablation device, resulting in sub-optimal performance. The needle cannot be relocated during the ablation procedure and the endoscope must be reinserted whenever it is necessary to reposition the needle guide. Reinserting and removing the endoscope and ablation device every time the needle must be repositioned increases the time and expense of the surgery.
U.S. Pat. No. 6,379,348 to Onik describes a mylolysis needle that is a combination of a cryosurgical and electrosurgical instrument for tissue ablation. The cryo/electro needle is not easily visualized when in use and requires the use of a dilator to create an access channel in the tissue area where the needle is to be inserted. Similar to laparscopic surgery, placement of the cryo/electro needle is done blindly and may not result in optimal performance.
Thus, a need exists to provide a medical needle system and method that can provide accurate and reliable targeting of fibroid tumors. It is also desirable to provide a needle that has a safety system that would shut-off electrical current to the needle if the uterine wall is punctured.
The invention provides a medical needle for transvaginal ultrasound directed reduction of fibroids. The medical needle is adapted for use in conjunction with a transvaginal ultrasound probe. The ultrasound probe has an attached needle guide through which the needle is inserted. The needle has an outer tubular member having an inner surface, a distal end, and a proximal end. The distal end of the outer member is made of an echogenic material so that the tip of the needle has heightened visibility on an ultrasound screen. Located at the distal end is an active electrode that is in communication with a radiofrequency source. An insulating sheath surrounds the entire outer member except for a section that is near the active electrode at the distal end.
The needle has a return electrode that is optionally located on the outer member near the active electrode or on an outer tissue surface of a patient. Optionally, the needle may have a temperature sensor that is located near the active electrode. Typically, the distal end will either be a sharpened pointed tip or a beveled tip that defines an opening in the distal end.
In a preferred embodiment, the needle has a safety device that will turn off power to the active electrode if the tip of the needle should penetrate a patient's uterine wall. In the embodiment possessing a beveled tip, an inner cylindrical member having a forward end and blunt rear end is disposed within the outer member. The inner member has a cylindrical outer section that is electrically conductive and a section that is not electrically conductive. Disposed on the inner surface of the outer member is a second electrically conductive surface and a third electrically conductive surface that are not in communication with one another. The second surface is in communication with the RF power source and the third surface is in communication with active electrode.
A spring is attached to the forward end of the inner member and the blunt rear end extends outwardly beyond the beveled tip. When pressure is applied to the blunt rear end the spring is compressed and the exposed blunt rear end slides backwardly into the outer member. As the inner tubular member slides into the outer member the electrically conductive surface comes in contact with both the second and third surface so that current passes through the surfaces and RF energy is supplied to the active electrode.
In a second embodiment having a safety device, the inner tubular member does not have a conductive surface and there are no second and third conductive surfaces. Rather, a switch is located at the proximal end of the outer member. When pressure is applied to the blunt rear end of the inner member, the inner member slides back into the outer member and thereby closes the switch. When in the closed position, the switch sends a signal to the RF source and RF energy is applied to the active electrode.
In a third embodiment, the needle has an outer member, an inner surface, an echogenic distal end, and a proximal end. As in the first embodiment, the echogenic material results in the tip of the needle having a heightened visibility. Within the outer member is a cryogen tube that extends longitudinally from the proximal end to the distal end. Surrounding a section of the outer member from the proximal end to near the distal end is a cryo-insulation sheath. The distal end is in communication with a cryogen supply so that the distal end can be in cryogenic contact with fibroids.
The length of the needle in all embodiments is typically from about 25 to 50 centimeters, and somewhat more typically between 30 to 40 centimeters. The diameter of the needle in all embodiments is typically from about 12 to 18 gauge, and somewhat more typically from about 16 to 18 gauge. Normally, the needle has a handle at the proximal end that allows the user to easily grip and manipulate the needle.
The invention also includes a method for the electric surgery of fibroids using a transvaginal ultrasound directed echogenic needle. The method comprises the steps of providing a transvaginal ultrasound probe having a transducer and attached needle guide; providing an echogenic needle as described above; inserting the probe into a patient's uterus; inserting the needle into the uterus through the attached needle guide; sensing the location of the needle and fibroid using ultrasound imaging; guiding and positioning the needle on the surface of a fibroid using ultrasound imaging; and passing a controlled amount of RF energy through the fibroid. The method optionally includes the steps of monitoring tissue temperature, penetrating the surface of the fibroid with the distal end of the needle, and the step of turning off power to the active electrode if the distal end pierces the uterine wall.
The invention additionally includes the method for the cryoablation of fibroids in the uterus using a transvaginal ultrasound directed echogenic needle. The method includes the steps of providing a transvaginal ultrasound probe having a transducer and an attached needle guide; providing a cryoablation echogenic needle as described above; inserting the probe into the uterus; inserting the echogenic needle into the uterus through the attached needle guide; sensing the location of the needle and fibroid using ultrasound imaging; guiding and positioning the needle on the surface of a fibroid using ultrasound imaging; delivering a controlled amount of cryogenic supply to the distal end of the needle while it in contact with the surface of the fibroid. The method optionally includes the step of penetrating the fibroid with the distal end of the needle before or after delivering a controlled amount of cryogenic supply.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
Referring more specifically to the drawings, for purposes of illustration, but not of limitation, there is shown in
As illustrated in
In all embodiments, the needle will have an echogenic surface 135 at or near the distal end 120. For example,
Inserting both the ultrasound probe and echogenic needle into the uterus through the vagina is very advantageous. Traditional laparoscopic myomectomy requires that the ablation needle be inserted into the uterus through the abdomen. During this procedure the needle must be inserted through the uterine serosa, which may result in the formation of uterine adhesions. In contrast, the invention provides an apparatus and method of use for fibroid myomectomy that is a minimally invasive surgical procedure. Adhesions are not expected to form with this method because the echogenic needle is inserted through the vagina rather than penetrating the uterine serosa. A second advantage of the invention is precision and accuracy. The echogenic needle has a heightened ultrasonic visibility that allows the physician to accurately locate and position the needle within the uterus. As a result, the surgical procedure is performed more quickly, the needle is easily repositionable by the surgeon, and most importantly the procedure will have a greater beneficial impact for the patient.
With reference to
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The RF needle of the invention delivers either monopolar or bipolar current. With reference to
With reference to
In contrast to the first embodiment, RF needle 400 has a sharpened beveled tip 190, an inner cylindrical member 405, and a spring 430 disposed within the outer member 115 at the outer member's proximal end 125. The inner member 405 is disposed and moveable longitudinally within the outer member 115. As illustrated in
In a first embodiment of RF needle 400, a segment of the inner cylindrical member has a cylindrical conductive surface, and outer member 115 has a second and third conductive surfaces on its inner surface. The second surface is in communication with the RF power supply 140, and the third surface is in communication with the active electrode 175. When in the rest position, the second and third surfaces are not in communication with each other. As pressure is applied to the blunt rear end 425 the inner member 405 retracts into a charged position. When in a charged position, the conductive surfaces 410, 415, and 420 are in communication and RF energy flows from the RF power source to the active electrode. If the distal end 120 punctures the uterine wall pressure against the blunt rear end 425 will be released and the spring 430 will rapidly extend the blunt rear end 425 outwardly. As a result, the conductive surface 410 will move longitudinally away from the second and third surfaces 415, 420 and RF energy supplied to the active electrode is shut-off. The exact position of conductive surfaces 410, 415, and 420 is not critical except that it is necessary that all three surfaces simultaneously communicate with each other when the inner member is in a retracted position.
In this regard,
The active electrode is at the distal end 120 or alternatively, the noninsulated surface 120 a of the outer member 115 is the active electrode. In this regard,
In a second embodiment of a needle having a safety mechanism 400, the active electrode is located at the blunt rear end. As shown in
However, the electrical connector 425 a may be disposed between the surface of the inner member and an optional RF insulation sheath that surrounds the inner member. The optional insulation sheath does not surround the conductive surface 410 or the active electrode 175.
In a third embodiment of a RF needle with a safety mechanism 400, the inner member is connected to a switch. With reference to
In all the embodiments of a needle having a safety mechanism 400 the inner member 405 is typically made from a material that is non-conductive, such as a plastic. Normally, a non-conductive member will have a conductive material, such as stainless steel, inserted into a surface segment so that the inner member has an electrically conductive surface that will contact the second and third surfaces on the outer member. Somewhat more typically, the inner member is made from a metal such as stainless steel that is surrounded by a RF insulation sheath. The insulation sheath surrounds the inner member except for the conductive surface 410, which is RF non-insulated.
With reference to
Typically, cryogenic liquids such as nitrogen, helium and argon are used to produce the cryogenic effect in the targeted tissue.
In all embodiments, it is necessary that the needle is longer than the ultrasound probe and has sufficient length to reach fibroids deep in the uterus. Typically, the length of the needle is about 25 to 50 centimeters, and somewhat more typically about 30 to 40 centimeters. The needle's diameter is dictated by the ultrasound probe's attached needle guide. Typically, the diameter of the needle is about 12 to 18 gauge, and somewhat more typically about 16 to 18 gauge. However, the needle is not limited to the above recited dimensions and may be varied depending upon the actual length of the probe and the needle guide's inner diameter. Typically, the outer member is made of any material that is suitable for insertion into tissue, such as stainless steel.
Optionally, as shown in
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.