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 PCT 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. An array of electrodes is 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 the electrodes are energized under computer control. The electrodes heat and shrink the engaged endopelvic fascia with minimal collateral damage to the surrounding fascia and tissues, while the device structure and controller will together generally avoid ablation of the engaged endopelvic fascia.
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.
In a first aspect, the present invention provides a method for use in a therapy for inhibiting incontinence. The therapy effects a desired contraction of a discrete target region within an endopelvic support tissue. The method comprises engaging a surface of a probe against the target region of the endopelvic support tissue. Energy is directed from an array of transmission elements disposed on the probe surface into the support tissue so as to effect the desired contraction of the target region. The energy directing step is performed without moving the probe.
The energy directing step will often comprise transmitting the energy across a probe surface/tissue interface having a length of at least 10 mm and a width of at least 5 mm. The energy will be sufficient to contract the endopelvic support tissue with minimal damage to underlying tissue. In the exemplary embodiment, the energy directing step comprises applying bipolar electrical energy between a plurality of electrode pairs.
In another aspect, the present invention provides a method for use in a therapy for incontinence. The incontinence therapy includes effecting a desired contraction of an endopelvic fascia. The endopelvic fascia is composed of a left portion and a right portion. The method comprises accessing a first target region along the left or right portion of the endopelvic fascia. The first target region is offset laterally from the urethra. A probe surface is positioned against the first target region, and energy is directed from the positioned probe surface into the first target region so as to effect the desired contraction of the left or right portion of the endopelvic fascia. This energy is directed without moving the positioned probe surface.
Generally, a second target region along the other portion of the endopelvic fascia will also be accessed. The second region is offset laterally from the urethra, so that the urethra is disposed between, and separated from, the first and second target portions. Energy is directed from a probe surface into the second region so as to effect the desired contraction of the other portion without moving the probe surface. These energy directing steps may optionally be performed simultaneously, or may be performed sequentially by moving the probe from one side to the other. A protective zone of the probe surface can be aligned with the urethra to ensure that energy is not inadvertently transmitted from the treatment surface to this delicate tissue structure. Such alignment may be facilitated by introducing a catheter into the urethra.
In another aspect, the invention provides a method for selectively contracting a target tissue. The method comprises aligning a treatment surface of a probe with a first portion of the target tissue. The treatment surface has a peripheral portion and an interior portion. Energy is directed from the treatment surface into the first portion of target tissue so as to contract the first portion. Contraction of the first portion draws a second portion of the target tissue into alignment with the peripheral portion of the treatment surface. Energy can then be selectively directed from the peripheral portion of the treatment surface into the second portion of the target tissue. Advantageously, this allows tissue which was brought into alignment with the probe during the beginning of the treatment to be heated and contracted as it is drawn under the electrodes without over-treatment of the previously contracted tissue.
In another aspect, the invention provides a device for effecting a desired contraction of a discrete target region of a tissue. The target region has a target region size and shape. The device comprises a probe having a treatment surface with a size and shape corresponding to the size and shape of the target region. At least one element is disposed along the treatment surface for transmitting energy from the treatment surface to the target region without moving the probe such that the energy effects the desired contraction.
In another aspect, the invention provides a device for effecting contraction of a target fascial tissue. The target tissue has a fascial surface. The device comprises a probe body having a treatment surface. The treatment surface is oriented for engaging the fascial surface, and has a length of at least about 10 mm and a width of at least about 5 mm. The probe body is at least semi-rigid. An array of electrodes are distributed over the target treatment surface for transmitting energy into the engaged target tissue without moving the probe, such that the energy contracts the target tissue.
In yet another aspect, the invention provides a device for contracting a target tissue having a tissue surface. The device comprises a probe having a treatment surface oriented for engaging the tissue surface of the target tissue. An electrode is disposed on the treatment surface of the probe, and is engageable against the target tissue surface so as to contract the engaged target tissue from an initial size to a contracted size. The electrode comprises a peripheral portion and an interior portion. The interior portion has an area corresponding to the contracted size of the tissue. The peripheral portion is energizeable independently from the interior portion. This advantageous structure allows the tissue immediately surrounding the contracted tissue to be heated and contracted without overtreating (and imposing unnecessary trauma) on the previously contracted tissue.