1. Field of the Invention
The invention relates to devices and methods for treating incontinence. More specifically, particular embodiments of the invention use a variable control vacuum and/or vibratory device or other device to apply suction or other force to the male or female genital region, e.g. the region of the female urethral opening, the clitoral region and/or the vaginal region, or the male penile region.
2. Description of Related Art
A. Incontinence
Urinary incontinence is a significant clinical problem and a major source of disability and dependency. Although urinary incontinence is particularly prevalent in the elderly, it affects all age groups. Millions of male and female adult Americans suffer from urinary incontinence, including at least one-half of all nursing home residents. The monetary costs of managing urinary incontinence, and the psychological costs associated with the problem, are great. Fecal incontinence presents similar concerns.
The most frequently occurring types of urinary incontinence are stress incontinence, urge incontinence, overflow incontinence, and mixed incontinence. Stress incontinence is a common form of incontinence in women. Intra-abdominal pressure exceeds urethral pressure upon coughing, sneezing, laughing, lifting, or like activity, causing leakage of urine. Physical changes associated with pregnancy, childbirth, and menopause, for example, are known to cause stress incontinence.
Urge incontinence occurs when a patient loses urine while suddenly feeling the urge to urinate. The patient is unable to inhibit the flow of urine long enough to reach the toilet. Inappropriate bladder contractions are the most common cause of urge incontinence, and may occur in connection with central nervous system lesions, urinary infection, or bladder tumors, to name several examples.
Overflow incontinence occurs when the bladder is unable to empty normally. Weak bladder muscles, caused e.g. by nerve damage from diabetes, or a blocked urethra, caused e.g. by tumors or urinary stones, are among the more common causes of overflow incontinence. Frequency or urgency involves the need or urge to urinate on an excessively frequent or habitual basis. Combinations of these and other types of incontinence, e.g. stress incontinence and urge incontinence, are often called mixed incontinence.
Many options are available to treat incontinence in its various forms, including Kegel exercises, electrical stimulation, biofeedback, timed voiding or bladder training, medications, pessaries, implants, invasive or minimally invasive surgery, catheterization, and other methods and devices. Kegel exercises, or pelvic floor muscle exercises, for example, are intended to strengthen the muscles supporting the urethra, bladder, uterus and rectum. Weak pelvic floor muscles can contribute to urinary incontinence problems; hence strengthening those muscles can tend to alleviate those problems.
According to several known surgical treatment methods, one or more stimulation systems, including electrodes controlled by an electronic control system, are implanted to electrically stimulate nerves controlling external sphincter and bladder functions. The electronic control system directs the administration of electric pulses to stimulate the nerves appropriately. Note U.S. Pat. No. 4,771,779, for example, which is incorporated herein by reference. U.S. Pat. No. 6,055,456, also incorporated herein by reference, shows an implantable medical lead for stimulation of the sacral nerves to treat incontinence.
Although treatments requiring surgical intervention may be the preferred and most effective treatment mode in some situations, surgical intervention may be too extreme a measure in other situations. In some cases, surgical procedures to treat incontinence actually have a relatively low success rate; in many cases such procedures are irreversible. Additionally, a patient may hesitate to proceed with a surgical option, and/or a patient's physical condition may make surgical intervention inappropriate. Surgery may be inappropriate for pregnant patients, for example, or those of advanced age. Similarly, pharmacological treatment options may cause undesirable side effects and/or interactions with other medications. Non-surgical treatments, for example exercises or bladder training, may demand too high a degree of patient compliance or effort and thus may be resisted or otherwise ineffective.
A need exists, therefore, to treat urinary and/or fecal incontinence in a non-invasive, non-pharmacological manner that is less likely to meet with patient resistance or cause physical trauma or side effects.
B. Urogenital Anatomy
The female urethra passes just anterior to the vagina, and the external female urethral orifice is just posterior to the clitoris. The external urethral sphincter and the compressor urethrae compress the urethra and serve as functional sphincters. The pudendal nerve, which is derived from the anterior divisions of the ventral rami of S2 through S4, is the chief nerve of the perineum, providing sensation to the genitalia including the clitoris and controlling the motor function of the external urethral sphincter and the external anal sphincter. In the male, the pudendal nerve provides sensation from the penis and scrotum and provides motor control to the pelvic floor, including the anal sphincter.
C. Clitoral Anatomy
The clitoris in the human female consists of a cylindrical, erectile organ composed of three parts: the outermost glans or head, the middle corpus or body, and the innermost crura. The glans of the clitoris is visualized as it emerges from the labia minora, which bifurcates to form the upper prepuce anteriorly and the lower frenulum posteriorly. The body of the clitoris consists of two paired corpora cavernosa of about 2.5 cm in length. The body extends under the skin at the corona to the crura. The two crura of the clitoris, formed from the separation of the most proximal portions of the corpora in the perineum, attach bilaterally to the undersurface of the symphysis pubis at the ischiopubic rami.
A fibrous tunica albuginea ensheathes each corporal body made up of lacunar space sinusoids surrounded by trabecula of the vascular smooth muscle and collagen connective tissue. No retractor clitoridis muscle exists in humans as it does in other animals such as cattle and sheep, however a supporting suspensory ligament does hold the clitoris in the introital region.
The main arterial supply to the clitoris is from the ilio-hypogastric-pudendal arterial bed. The internal pudendal artery is the last anterior branch off the internal iliac artery. Distally, the internal pudendal artery traverses Alcock's canal, then terminates as it supplies the inferior rectal and perineal artery which supply the labia. The common clitoral artery continues to the clitoris. This artery bifurcates into a dorsal clitoral artery and a cavernosal clitoral artery.
In the normal female, autonomic efferent innervation of the clitoris passes from the pelvic and hypogastric nerves to the clitoris. Pelvic nerve stimulation results in clitoral smooth muscle relaxation and arterial smooth muscle dilation, causing an increase in clitoral cavernosal artery inflow and an increase in clitoral intracavernous pressure, which lead to tumescence and extrusion of the glans clitoris.
The clitoris has a dense collection of Pacinian corpuscles, Meissner's corpuscles, Merckel tactile disks, and free nerve endings. These sensory afferent nerves pass through the dorsal clitoral nerve to the pudendal nerve and into the sacral nerve roots (S2, S3, S4). (The male anatomy is completely homologous.) The presence of at least one somatic reflex arc is demonstrated by the bulbo-cavernosal reflex; squeezing the clitoris causes the anal sphincter to contract—the so-called “anal wink.”
D. Female Sexual Dysfunction
Clitoral erectile insufficiency or reduced clitoral arterial flow may be caused by atherosclerosis, diabetes, or age-related causes, among other factors. Reduced clitoral arterial flow may lead to fibrosis of the clitoral cavernosa and reduced clitoral physiological function. In an animal model, Park et al. demonstrated that significant collagen synthesis occurs when the arterial inflow to the clitoris is compromised. This work demonstrated the importance of maintaining arterial flow to the clitoris to prevent collagen synthesis and fibrosis on the smooth muscle. See Park, K., et al., Vasculogenic Female Sexual Dysfunction: The Hemodynamic Basis for Vaginal Engorgement Insufficiency and Clitoral Erectile Insufficiency, IJIR, 9:27-37, 1997.
It is believed that the difficulty or inability to achieve clitoral tumescence may be related to and associated with other symptoms of female sexual arousal disorder. According to the International Consensus Report on Female Sexual Dysfunction, Female Sexual Arousal Disorder (FSAD) is defined as the persistent or recurrent inability to attain or maintain adequate genital lubrication or swelling responses resulting in personal distress. FSAD may be expressed as a lack of subjective excitement or lack of genital (lubrication/swelling) or other somatic responses (AFUD Consensus Report of FSD, 1998).
A non-pharmacological approach to treatment that causes blood flow and engorgement, thereby applying a stimulus to the sensory nerve endings in the clitoris, periurethral area, and/or genital area, would be very beneficial to a large group of women complaining of FSAD.