Incontinence is defined as the involuntary leakage of urine from the bladder. Incontinence can affect both men and women in any age group but is more common in women and the elderly. As the population ages, the number of people suffering from bladder control problems is increasing. The costs of this problem are personal, physical and financial, and many with incontinence suffer social embarrassment, isolation, ill health and even depression.
Normal urinary continence and bladder control requires a complex interaction between the brain, nervous system and organs in the pelvis. The pelvic organs include the bladder, urethra, the prostate in men and the muscles of the pelvic floor called the levator ani. Controlling the outflow of urine are two valves, or sphincters, located in the bladder neck and earliest portion of the urethra. The bladder neck sphincter is under involuntary (autonomic) control while the urethral sphincter has both voluntary and involuntary components. The levator ani muscles act as a supporting hammock for this system and also have reflex as well as voluntary activity.
The bladder has two essential functions: to store urine and to empty urine. While this concept is simple, the interplay necessary between the brain, bladder, sphincters and pelvic floor muscles is very complex. Perceptions of bladder filling and fullness, and subsequent initiation of emptying requires synchronization of the nervous system, the bladder muscle, sphincters and pelvic floor. Similarly, controlling a full bladder in the face of daily activity relies on precise neural orchestration and healthy pelvic organs.
When any component of the system loses normal function, urinary control can be affected. Neural injury, damage to the bladder, sphincters, supporting structures and even the pelvic floor can all lead to incontinence. It is important to understand that treatment is available. Incontinence is not something to accept as a result of age, surgery, childbirth or related illness. Our understanding of the mechanisms of urine leakage and therapies to restore control continue to progress. The first step toward treatment, however, is recognition of the problem. Incontinence is a burden that can be lifted.
Classification of Incontinence
Incontinence is classified by both causes and symptoms. The two most common types are called urge incontinence and stress incontinence. Urge incontinence is primarily bladder "misbehavior," and as such is characterized by spontaneous and uncontrolled urine leakage, often accompanied by the overwhelming sensation of needing to void. This condition is also referred to as bladder instability or overactive bladder. Many people with this condition also have difficulty with bowel control and report frequent bowel movements or difficulties with constipation.
The causes of urge incontinence are not clearly known. It is likely that changes in the nerves controlling the bladder or the bladder muscle itself play important roles. Learned voiding behaviors, ageing, hormonal changes, childbirth, surgery, dietary habits and other factors appear to influence this condition.
In contrast to urge incontinence, stress incontinence is primarily due to weakness of the valve mechanism (sphincter) in the bladder outlet and urethra. This may be due to intrinsic changes in the urethra, or loss of support and strength of the bladder neck and adjacent structures (pelvic relaxation, cystocele, pelvic organ prolapse). It is also associated with postsurgical or radiation changes in men following treatment for prostate cancer. With physical exertion or activity that increases abdominal pressure, urine is forced through the deficient valve.
These two types of incontinence can be present separately or in combination. For this reason, proper evaluation is needed to direct appropriate therapy.
Another type of leakage is termed overflow incontinence. This results from failure of the bladder to empty either from intrinsic weakness, nerve injury or blockage to flow. With an overfull bladder, exertion or abdominal pressure can cause urine to spill out. Overflow incontinence can sometimes be confused with stress and urge incontinence. Proper evaluation and testing is necessary for correct diagnosis.
Other conditions, such as urinary tract fistulae (holes between the urinary tract and other structures), stroke, spinal cord injury and other neurologic diseases can also cause incontinence and voiding problems.
Therapy for Urge Incontinence
Therapy for urge incontinence usually begins with attempts to retrain the bladder and its behavior. Awareness and strengthening exercises are used to develop proper function of the pelvic muscles, bladder and sphincter valve. These muscles play an important role in the conscious and unconscious control of bladder emptying. These exercises are generally referred to as Kegel exercises and require mastery of movements of the pelvic floor muscles. Retraining the bladder and voiding habits takes dedicated practice and time but is associated with a high success rate in those who expend the effort.
Coupled with bladder and pelvic floor retraining, certain medicines have proven helpful in controlling urgency and urge incontinence. A class of medicines called anticholinergics help to decrease the number of voiding and incontinence episodes as well as the volume of any leakage. Oxybutynin (Ditropan) and tolterodine (Detrol) are the most commonly used. While these medicines are helpful for bladder control, certain side effects can be bothersome. Dry mouth, dizziness and blurred vision can decrease the tolerability of these agents. Other medicines helpful in controlling the bladder muscles and sphincter are hyoscyamine (Levsin), amitriptyline (Elavil), imipramine (Tofranil) and flavoxate (Urispas).
As an adjunct to pelvic floor training and medication, biofeedback modalities are often helpful for managing urgency and urge incontinence. This technique uses audible or visual reinforcement in developing control of the pelvic floor muscles. A device that can measure pelvic muscle pressure or activity is inserted into the vagina or rectum. Conscious contraction of the pelvic floor muscles causes a bell or beep to sound or a series of lights to flash. This sequence helps to reinforce the proper responses for building muscle and bladder control. Therapy is usually started in the office setting and continues with a home program. Certain devices are portable and suitable for home therapy.
Results of biofeedback vary from about 50 percent to 80 percent. This wide variation among studies is likely due to the heterogeneity of incontinence disorders in participating patients. Nevertheless, many people find benefit from this therapy, which is essentially noninvasive and free from side effects.
For those patients with persistent urgency, frequency and urge incontinence in the face of conservative therapy, an exciting new therapy called sacral neuromodulation is proving effective. This therapy is directed at the nerves controlling the bladder. By using a small electrical current similar to that in a heart pacemaker, bladder behavior can be improved. The therapy is first tested temporarily as an outpatient and if successful is followed by permanent implantation of a small stimulator near the tailbone. Results of this therapy have been outstanding with excellent durability.
In certain cases, bladder surgery can be helpful to control the most difficult symptoms of urinary frequency and urge incontinence. Augmentation cystoplasty is one such operation associated with satisfactory results.
Therapies for urge incontinence continue to emerge as we continue to enhance our understanding and appreciation of the causes, severity and prevalence of the condition.
In 1956, Arnold Kegel described the exercises that bear his name. The technique begins by identifying the muscles of the pelvic floor (levator ani). In women, this can be done by feeling the muscles to the side and floor of the vagina (pubococcygeus) with a finger. Contraction of these muscles causes the floor of the pelvis to rise. One should be able to do this without contribution from the abdominal or buttock muscles. It is helpful to begin learning the technique with practice in the supine (lying down) position and progress to sitting and standing. While supine, the abdomen should not contract and the buttocks should not elevate with initiation of a Kegel contraction. One can also localize this movement by attempting to slow or stop the urine stream during voiding.
When the correct movement is learned, two different types of contractions can be performed:
Be sure to completely relax the pelvic floor before initiating another contraction. One can perform sets of exercises in the morning and evening. The important thing is to set aside dedicated time for practice. This skill takes time to acquire and is only as valuable as the effort put toward mastering it. Results can be seen after as little as two to three weeks but may not be fully appreciated for three to six months.
Pelvic floor training helps to develop strength and awareness of the supporting muscles of the pelvis, which are intimately related to bladder and rectal function. It helps to unmask and facilitate local reflexes that inhibit unwanted bladder contractions associated with urge incontinence. Increasing pelvic floor strength may help to combat exertional leakage associated with stress incontinence due to slight weakness of the sphincter, if one can initiate a contraction prior to coughing, sneezing, lifting or other exertions.
Reference: Kegel AH. Stress incontinence of urine in women: physiologic treatment. J Int Coll Surg 1956;25:487.
Sacral nerve modulation (InterStim, Medtronic, Columbia Heights, Minn.) is an exciting new therapy for intractable urinary urgency, frequency and urge incontinence. It is also effective for reversing cases of idiopathic urinary retention (failure to empty the bladder). This therapy borrows many of the concepts and technology of heart pacemakers. In a similar fashion to a pacemaker, a device delivers small repetitive electrical impulses to stimulate nerves to the bladder. These nerves travel just beneath the sacrum (tail bone).
The value of this therapy was recognized more than a decade ago and has gradually developed to its current state. Experience in Europe over the past five years has contributed to growing success in this country.
One of the advantages of this therapy is that the stimulation can be given on a temporary basis following a minor office procedure. A trial of therapy, called a test stimulation can be conducted for up to one week to allow assessment of success and suitability for permanent implantation. The results can be dramatic, with significant resolution of frequency episodes and leakage. This procedure takes about 30 minutes and involves placement of a thin wire lead near a nerve to the bladder. This lead is then connected to a device similar in size to a pager that delivers the impulses.
During the test phase, a diary is kept charting the frequency and volume of urination as well as leakage episodes and any pain symptoms. When completed, the test stimulation lead is removed painlessly, the stimulator is returned and the results are reviewed.
If test stimulation is successful, one can consider permanent device implantation. This latter phase involves a short surgery to place a more durable stimulator lead near the nerve previously tested.
This lead is then tunneled under the skin of the lower back and connected to a pulse generator similar in size to a pocket watch with a thickness of an inch. This IPG is positioned beneath the skin of the upper buttock below the belt line.
The neural stimulator does not impair sitting, sleeping, exercise or other activities. Both patient and physician can control device performance to achieve optimal results.
Important aspects of this therapy are its reversibility and minimal invasiveness. It does not change any of the body's structures and uses the intrinsic "wiring" of the body and bladder to achieve the desired effect.
Weil EH et al. Sacral root neuromodulation in the treatment of refractory urinary urge incontinence: A prospective randomized clinical trial. Eur Urol 2000;37(2):161.
Shaker H, Hassouna MM. Sacral root neuromodulation in the treatment of various voiding and storage problems. Int Urogynecol J Pelvic Floor Dysfunct 1999;10(5):336.
Therapy for Stress Incontinence
In contrast to urge incontinence, treatment of stress incontinence focuses less on bladder behavior than on the structure and function of the bladder and sphincter valve. Kegel exercises designed to improve pelvic muscle strength have an important role in mild degrees of stress incontinence and in maintaining health and function of the lower urinary tract. For more significant degrees of exertional leakage, many options are available. These include temporary devices to support, close or plug the urethra, injection of urethral bulking agents into the bladder neck and sphincter area to help its closure and surgical procedures to restore function of the valve mechanism.
Stress incontinence is thought to result from either loss of support for the bladder neck and sphincter area or intrinsic damage to the urethra and sphincter itself. Again, each of these entities may be present singly or in combination, and accurate diagnosis is important for treatment planning. Many procedures done previously, such as the Kelly plication and bladder suspension of the Raz, Stamey and Pereyra type, have not shown satisfactory durability to warrant their use.
Surgical procedures for restoring continence can be performed through an abdominal incision, laparoscopy or a vaginal approach. The most reliable of these procedures in women are the Burch colpocystourethropexy and the pubovaginal sling. The sling procedure places a strong material beneath the urethra and bladder neck to provide strength to the sphincter valve and restore its function. Results show excellent durability with low complication rates for patients of all ages. For males with significant stress incontinence, the favored surgical therapy is placement of an artificial urinary sphincter. This is a mechanical device designed to replace the sphincter valve. It provides closure of the valve on a continuous basis and is opened by squeezing a small pump implanted beneath the skin of the scrotum. This allows unrestricted voiding, after which the device closes automatically.
Urethral Bulking Agents
Part of the mechanism of stress incontinence involves failure of the sphincter valve to form a seal adequate to hold back leakage. This lack of sphincter closure is due to changes in the muscular wall and lining of the urethra. A minimally invasive therapy for this condition involves the injection of a biocompatible material into the sphincter area to help it close. The material used is similar in type and technique to that used by plastic surgeons in treating facial wrinkles and contouring. The procedure can be performed in the office under a local anesthetic and is well tolerated. A cystoscope is inserted into the urethra and used to direct the injection into the appropriate site.
In the majority of cases, two to three sessions are necessary to achieve a satisfactory result. These sessions are usually done at four- to six-week intervals. The rate of improvement in continence is 60 percent to 70 percent, while the overall cure rate (complete dryness) is lower (15 percent to 25 percent). Results are generally poor in men suffering from incontinence as a result of radical prostatectomy.
Reference: McGuire EJ, et al.: Periurethral collagen injection for male and female sphincteric incontinence: indications, techniques, and result. World J Urol 1997;15(5):306.
A sling operation is currently the most effective therapy for significant stress urinary incontinence due to weakness of the urethral sphincter. This procedure requires one to two hours of operative time and an overnight stay in the hospital. Through a vaginal approach, small incisions are made beneath the bladder neck and urethra.
A strong and durable material from the body called fascia is placed beneath the bladder neck to provide support when pressure is placed on the bladder from a sneeze, cough, exercise or other activity
This fascia is obtained from the thigh (through an additional small incision), abdomen (through an incision over your pubic bone) or from a donor. A catheter placed through the urethra or the abdominal wall is usually left in place overnight or for a few days following surgery.
Results are immediate but a healing period of modified activities is usually recommended for four to six weeks. This operation has a success rate of more than 90 percent and has excellent durability.
Chaikin D et al. Results of pubovaginal sling for stress incontinence: a prospective comparison of 4 instruments for outcome analysis. J Urol 1999 Nov;162(5):1670-3.
Wright EJ et al. Pubovaginal sling using cadaveric allograft fascia for the treatment of intrinsic sphincter deficiency. J Urol 1998 Sep;160(3 Pt 1):759-62.
3. Carr LK, Walsh PJ, Abraham VE, Webster GD. Favorable outcome of pubovaginal slings for geriatric women with stress incontinence. J Urol 1997 Jan;157(1):125-8.
Artificial Urinary Sphincter
The artificial urinary sphincter (AUS) is a hydraulic biocompatible device with three components.
There is a fluid-filled reservoir roughly the size of a golf ball that is implanted in the groin area next to the bladder. A pump device about the size and shape of a thumb is placed inside the scrotum in front of one of the testicles. The last piece is a circular inflatable cuff that is placed around the urethra and sphincter area.
When activated, the cuff compresses the urethra with sufficient pressure to withstand forces associated with most activities. When one has the usual sensation of a full bladder, the pump in the scrotum is pressed between the fingers twice to allow the cuff to open. Voiding is completed in the normal fashion, and the device automatically closes over one to two minutes. Implantation of this device generally requires a two-hour surgery and an overnight stay in the hospital. The device is left inactivated for a period of four to six weeks following implantation to allow for successful healing and recovery. After this waiting period, the device is turned on and results are immediate. The materials in the AUS are durable for a period of seven to 10 years. If they wear out, they can be replaced as an outpatient with a 40- to 60-minute operation. The AUS is associated with significant improvement in quality of life in the majority of men with significant stress urinary incontinence.
Haab F et al. Quality of life and continence assessment of the artificial urinary sphincter in men with minimum 3.5 years of follow-up. J Urol 1997Aug;158(2):435.