BACKGROUND OF THE INVENTION

1. Field of the Invention

This application relates to a system and method for delivering therapeutic agents to a patient and, more specifically, to a uterine cavity for endometrial ablation.

2. Background

Abdominal Uterine Bleeding (AUB) is excessive bleeding from the vagina that lasts more than seven days. Heavy periods can cause pain and discomfort and increase the risk of iron-deficiency anemia. Acute excessive bleeding can lead to hemodynamic instability, requiring hospitalization for fluid volume management, blood transfusion, and/or intravenous estrogen. This condition has a significant negative impact on woman's sexual functioning, mental well-being and overall health.

Studies have shown that Abdominal Uterine Bleeding affects approximately 1 in 3 women in their lifetime. This is over 200 million women worldwide. In the U.S. alone, there are ten million women suffering from AUB with 200,000 newly diagnosed women each year. The conservatively estimated annual direct economic cost of AUB in the US is approximately $1-1.55 billion and indirect cost is $12-36 billion.

There are four groups of treatment options that are currently available for treating AUB: 1) Dilatation and Curettage (D&G); 2) Hysterectomy; 3) Intrauterine device (IUD) and 4) Global endometrial ablation (GEA). Each of these treatments has significant disadvantages. Dilation and Curettage offers a short-term relief and has a high risk of perforations. This option is not in wide use. Hysterectomy is a surgical removal of the uterus, which involves major surgery done under general or regional anesthesia. Due to its invasive nature, high costs and risks, the number of these procedures has dropped over 50% in the last decade. Intrauterine devices, such as the Bayer HealthCare′ “Mirena” IUD, are not highly effective and have significant side effects and risks. Use of the Mirena IUD to control heavy menstrual bleeding in women seeking contraception has increased in popularity. This is mainly because many clinicians are uncomfortable with the existing methodologies which require extensive training and skill as well as anesthesia and are mostly performed in “OR setting” facilities. However, due to ease-of-use and relatively low cost of this treatment option, the use has been growing. Global Endometrial Ablation devices, such as the Hologic “NovaSure”, the Boston Scientific “Genesys HTA” and the Cooper Surgical “Her Option”, are currently being utilized to ablate endometrium. The procedure can be done in a hospital setting or in the office. This is the most common option for treatment of AUB in the U.S. The procedure has demonstrated high efficacy, but is rather complex for in-office use and relatively expensive. Thus, GEA and IUD devices are the primary options for AUB treatment that are currently offered.

Endometrial ablation techniques, which have evolved as an alternative to hysterectomy, (e.g., laser, resecting loop with electric current, electric rollerball, thermal fluid-filled balloon, radiofrequency, freezing, heated saline) remove some of the lining of the uterus in an attempt to control excessive bleeding. After endometrial ablation, pregnancy is not likely to occur.

The early techniques of endometrial ablation, introduced in the 1980s and still used today (although much less commonly) involve the use of a hysteroscope with either a “rollerball” or wire loop through which electrical heat travels to remove (resection) the endometrial lining. After the uterus is filled with fluid to enlarge it for better viewing, the surgeon moves the rollerball back and forth across the lining or uses the wire loop to shave off the tissue. Potential risks of this ablation method include infection, perforation of the uterus, cervical laceration, and fluid overload.

In 1997, the Food and Drug Administration (FDA) approved ThermaChoice, the first non-hysteroscopic ablation device to treat excessive uterine bleeding (menorrhagia) due to benign (non-cancerous) causes. The Gynecare ThermaChoice Uterine Balloon Therapy System has a balloon that is inserted through the neck of the cervix and into the uterus. Through a catheter connected to a controller console, the balloon is inflated with fluid and heated to 188° F. (87° C.) for 8 minutes to destroy the uterine lining.

In 2001, the FDA approved three more similar devices. These devices are to be used only in women who have not yet reached menopause and whose child-bearing is completed. The BEI Medical Systems Hydro ThermAblator delivers heated saline solution into the uterus. The heated saline solution is delivered using hysteroscopic guidance. The heated solution destroys the uterine lining in about ten minutes. The CryoGen Her Option Uterine Cryoblation Therapy System uses a cryoprobe capable of producing temperatures down to minus 148° F. (minus 100° C.) at the tip. This extreme cold is applied to the tissue for ten minutes to freeze and destroy the uterine lining. Ultrasound is used to guide and monitor the procedure.

Currently available AUB treatment options are either invasive, ineffective, expensive or have a combination of these limitations. As a result, the market penetration for existing pharmaceutical and therapeutic options remains very low. Studies show that only 15.8% of patients received a therapeutic procedure within twelve months, post diagnosis. Studies also show that 38% of women with AUB undergo a hysterectomy, which is a major surgery, without even being offered less invasive alternatives. These studies show that physicians and patients are well-aware of these limitations and reluctant to use these treatment options.

There is a need for a non-invasive, easy-to-use (short learning curve), and effective device for treating AUB. It would further be advantageous to provide such treatment with a low cost device and low procedural costs. This would enable treatment of the patient population that currently remains untreated due to clinical and economic limitations of the current options. It would also be advantageous if such device ensured that the therapeutic agent is safely delivered to the endometrium in the uterine cavity.

SUMMARY

The present invention overcomes the deficiencies and disadvantages of the prior art. The present invention advantageously provides in preferred embodiments an apparatus for endometrial ablation that is easy to use, economical and controls the pressure of therapeutic agent applied to the endometrium. The apparatus of the present invention also in preferred embodiments apply a pre-check of the uterine cavity to ensure it is sealed before application of the therapeutic agent, thereby preventing exposure to other areas of the body. The therapeutic agent is preferably injected at a controlled pressure to maximize the surface of exposure of the endometrium (preferably the entire surface will be exposed) to the agent while preventing leakage to other areas.

In accordance with one aspect of the present invention, an apparatus for delivering a therapeutic agent to the uterine cavity of the patient is provided having an elongated member having a fluid channel for passage of the agent into a uterine cavity of a patient. The fluid channel has an opening. The dispensing member extends distally of the elongated member and is in communication with the fluid channel and has at least one perforation to provide exit openings for passage of the agent into the uterine cavity into contact with the endometrium, the agent injectable through the at least one perforation at a controlled pressure. In preferred embodiments, the therapeutic agent is a chemical agent for endometrial ablation.

In some embodiments, the dispensing member has a first condition for delivery having a first transverse dimension and a second condition for placement within the uterine cavity having a second transverse dimension greater than the first transverse dimension.

In accordance with another aspect of the present invention, an apparatus for delivering a therapeutic agent to the uterine cavity of the patient is provided having an elongated member having a fluid channel for passage of the therapeutic agent into the uterine cavity. The fluid channel has an opening. A dispensing member extends distally of the elongated member and has at least one perforation to provide for passage of the therapeutic agent into the uterine cavity into contact with the endometrium. An infusion line is in fluid communication with the fluid channel for passage of a fluid into the uterine cavity to assess leakage to determine integrity of the uterine cavity prior to passage of the therapeutic agent into the uterine cavity and the agent is injected at a controlled pressure. In preferred embodiments, the therapeutic agent is a chemical agent for endometrial ablation.

In some embodiments, the dispensing member has a first transverse dimension in a first condition for delivery to the uterine cavity and a second transverse dimension in a second condition for placement within the uterine cavity, the second transverse dimension being greater than the first transverse dimension.

In accordance with another aspect of the present invention, a system for delivering a therapeutic agent to the uterine cavity of the patient is provided having an elongated member having a fluid channel for passage of the agent into contact with the endometrium and a dispensing member extending distally of the elongated member. The dispensing member has a plurality of perforations to provide exit openings for passage of the agent into the uterine cavity into contact with the endometrium. A console has a pressure gauge, a receptacle to receive the agent, and a switch to control injection of the agent through the fluid channel of the elongated member. In some embodiments, the console includes a port to receive a tube from a source of pressurized fluid, the pressurized fluid injectable through the fluid channel into the uterine cavity to assess the presence or absence of leakage in the uterine cavity, and the pressurized fluid is injectable in a first position of the switch. In some embodiments, the pressurized fluid is injectable into the agent in the receptacle to inject the agent through the fluid channel at a higher pressure and a controlled pressure, the pressurized fluid injectable into the agent in a second position of the switch.

In some embodiments, dispensing member has a first condition for delivery having a first transverse dimension and a second condition for placement within a uterine cavity having a second transverse dimension greater than the first transverse dimension.

In accordance with another aspect of the present invention, a console for controlling fluid flow to a uterine cavity for an endometrial ablation procedure is provided, the console comprising a pressure gauge, a receptacle to store a chemical ablative agent, and a switch to control fluid flow. The switch has a first position to prevent fluid flow, a second position to enable pressurized fluid to flow into the uterine cavity and a third position to enable the pressurized fluid to flow into the receptacle to pressurize the ablative agent. In some embodiments, in the second position, the pressurized fluid flows into the uterine cavity to assess the presence of absence of leakage from the uterine cavity to check integrity of the uterine cavity.

In accordance with another aspect of the present invention, a method for injecting a therapeutic agent into the uterine cavity of the patient is provided comprising the steps of a) checking the integrity of a uterine cavity to determine if there is leakage from the uterine cavity; and b) if the integrity of the uterine cavity is confirmed, subsequently injecting the therapeutic agent into the uterine cavity under controlled pressure. In some embodiments, the integrity of the uterine cavity is checked by injection of pressurized fluid and a) determining if the pressure remains constant after injection of the pressurized fluid is terminated and/or b) determining if flow of the pressurized fluid ceases prior to being turned off. In some embodiments, the pressurized fluid is used to inject the therapeutic agent. In some embodiments, the therapeutic agent is a chemical ablation agent.

In some embodiments, the method further includes the step of moving a switch from a neutral position to a first position to align a first fluid line for injection of pressurized fluid. In some embodiments, the method further includes the step of moving the switch to a second position to align a second fluid line for injection of the pressurized fluid into the therapeutic agent to inject the agent at an increased pressure.

