1. Field of the Invention
The present invention generally relates to medical devices, methods and systems for selectively contracting tissues, particularly for the treatment of urinary incontinence.
Urinary incontinence arises in both men and women with varying degrees of severity, and from different causes. In men, the condition most frequently occurs as a result of prostatectomies which result in mechanical damage to the urethral sphincter. In women, the condition typically arises after pregnancy when musculoskeletal damage has occurred as a result of inelastic stretching of the structures which support the genitourinary tract. Specifically, pregnancy can result in inelastic stretching of the pelvic floor, the external sphincter, and the tissue structures which support the bladder and bladder neck region. In each of these cases, urinary leakage typically occurs when a patient""s abdominal pressure increases as a result of stress, e.g., coughing, sneezing, laughing, exercise, or the like.
Treatment of urinary incontinence can take a variety of forms. Most simply, the patient can wear absorptive devices or clothing, which is often sufficient for minor leakage events. Alternatively or additionally, patients may undertake exercises intended to strengthen the muscles in the pelvic region, or may attempt a behavior modification intended to reduce the incidence of urinary leakage.
In cases where such non-interventional approaches are inadequate or unacceptable, the patient may undergo surgery to correct the problem. A wide variety of procedures have been developed to correct urinary incontinence in women. Several of these procedures are specifically intended to support the bladder neck region. For example, sutures, straps or other artificial structures are often looped around the bladder neck and affixed to the pelvis, the endopelvic fascia, the ligaments which support the bladder, or the like. Other procedures involve surgical injections of bulking agents, inflatable balloons, or other elements to mechanically support the bladder neck.
An alternative surgical procedure which is performed to enhance support of the bladder is the Kelly plication. This involves midline plication of the fascia, particularly for repair of central defects. In this transvaginal procedure, the endopelvic fascia from either side of the urethra is approximated and attached together using silk or linen suture. A similar procedure, anterior colporrhaphy, involves exposing the pubocervical fascia and reapproximating or plicating portions of this tissue from either side of the midline with absorbable sutures. While the Kelly plication and its variations are now often used for repair of cystocele, this procedure was originally described for the treatment of incontinence.
Each of these known procedures has associated shortcomings. Surgical operations which involve midline plications or direct suturing of the tissues of the urethra or bladder neck region require great skill and care to achieve the proper level of artificial support. In other words, it is necessary to occlude or support the tissue sufficiently to inhibit urinary leakage, but not so much that intentional voiding is made difficult or impossible. Balloons and other bulking agents which have been inserted can migrate or be absorbed by the body. The presence of such foreign body inserts can also be a source of urinary tract infections.
Alternative devices, systems, and methods for treatment of urinary incontinence have recently been proposed in U.S. patent application Ser. No. 08/910,370, filed Aug. 13, 1997, and assigned to the assignee of the present invention. This reference, which is incorporated herein by reference, describes techniques for treating urinary incontinence by applying sufficient energy to tissue structures that comprise or support the patient""s urethra so as to cause partial shrinkage of the tissue, and thereby inhibit incontinence. Hence, these techniques generally involve selectively contracting a patient""s own pelvic support tissues, often applying gentle heating of the collagenated endopelvic structures to cause them to contract without imposing significant injury on the surrounding tissues. U.S. patent application Ser. No. 08/910,775, filed Aug. 13, 1997, describes related non-invasive devices, methods and systems for shrinking of tissues, and is also incorporated herein by reference.
While these new methods for treatment of incontinence by selectively contracting tissues represent a significant advancement in the art, still further improvements would be desirable for treating urinary incontinence in men and women. In particular, it would be desirable to provide devices and therapies to reliably and repeatably contract tissues so as to effect the intended physiological change. It would be best if these improved techniques and structures could provide reliable results independent of the normal variations in the skill and experience of the surgeon. It would further be desirable if these improved techniques could be performed using minimally invasive techniques so as to reduce patient trauma, while retaining and/or enhancing the overall efficacy of the procedure.
2. Description of the Background Art
The following U.S. patents and other publications may be relevant to the present invention: U.S. Pat. Nos. 4,453,536; 4,679,561; 4,765,331; 4,802,479; 5,190,517; 5,281,217; 5,293,869; 5,314,465; 5,314,466; 5,370,675; 5,423,811; 5,458,596; 5,496,312; 5,514,130; 5,536,267; 5,569,242; 5,588,960; 5,697,882; 5,697,909; and P.C.T. Published Application No. WO 97/20510.
The present invention provides improved devices, methods, and systems for repeatably and reliably contracting fascia and other support tissues, particularly for the treatment of urinary incontinence. The techniques of the present invention generally enhance the support provided by the natural tissues of the pelvic floor. Rather than relying entirely on the surgeon""s ability to observe, direct, and control the selective shrinking of these tissues, the present invention makes use of tissue contraction systems which are placed statically against the target tissue, and which direct sufficient energy into the tissue so as to inhibit incontinence or the like.
In the preferred embodiment, a thin semi-rigid or rigid credit card shaped device is inserted and urged flat against the endopelvic fascia. Interspersed heating and cooling areas are distributed across a treatment surface of the device, and the treatment surface will often be offset laterally from the urethra to avoid injury to the urinary sphincter or other delicate tissues. The treatment surface will often engage a relatively large area of the endopelvic fascia, and will be held in a static position against this tissue while energy from the heating areas heats and contracts the endopelvic fascia, preferably without ablating the endopelvic fascia. The interspersed cooling helps limit collateral damage to the surrounding fascia and tissues, and will also significantly enhance the rate of healing.
Advantageously, sufficient shrinkage can be provided by the device in the static position so that no additional heating/tissue contraction treatments may be required to the endopelvic fascia on the engaged side of the urethra. Hence, the present invention can take advantage of automated energy delivery circuits and/or selectable contraction probes having treatment surfaces of a variety of selectable sizes and shapes so as to predictably contract the target tissue, rather than relying entirely on a surgeon""s skill to contract the proper amount of tissue, for example, by manually xe2x80x9cpaintingxe2x80x9d a small electrode along the tissue surface, and may also reduce fouling along the electrode/tissue interface. A variety of heating elements can be used, including electrodes (both monopolar and in bipolar pairs), resistive heaters, preheated thermal masses, hot fluid conduits, exothermic reactive chemicals, and the like. Similarly, cooling could be provided by a variety of cooling elements such as chilled fluid conduits, endothermic reactive chemicals, thermoelectric cooling, chilled irrigation ports, and the like.
In one aspect, the invention provides a probe for contracting a target tissue of a patient body. The target tissue has a tissue surface, and the probe comprises a body having a tissue engaging surface. At least one cooling element is disposed on the tissue engaging surface of the probe. The at least one cooling element has a tissue cooling area. At least one energy applying element is also disposed on the tissue engaging surface of the probe. The at least one energy applying element has a tissue heating area that is interspersed with the tissue cooling area. These areas will generally be arranged so as to minimize injury to the target tissue when energy is directed from the tissue heating area to shrink the target tissue.
In another aspect, the invention provides a system for contracting a collagenous tissue. The system comprises a surface oriented for engaging the tissue, and an energy source that applies sufficient energy to selectively contract a portion of the engaged tissue. At least one element is coupled to the energy source so as to selectively transmit the energy through the surface and into the tissue so that the contracted portion is interspersed with other engaged tissue.
In yet another aspect, the invention provides a kit for contracting a collagenous tissue. The kit comprises a probe having at least one energy transmitting element. Instructions are provided for using the probe to direct energy from the probe into a portion of the tissue so as to contract the portion, and so that the contracted and uncontracted portions define an interspersed pattern. This interspersed pattern may significantly increase the rate of the healing process, regardless of whether active cooling is provided.