Out in the Open: Urinary Incontinence No Longer a Silent Affliction
Silence may be golden, but not if it keeps you from getting help for urinary incontinence. For of all the urologic conditions, those concerning leaking urine are often the most neglected, especially by women—who make up 85 percent of incontinence sufferers. In either gender, the condition appears in various forms, involving various parts of the anatomy (the bladder, urethra and sphincter) as well as the central nervous system, and triggered by various causes. Stress incontinence is common to women; post-surgical incontinence is most frequent in men who have undergone prostatic surgery.
Civilization's earliest physicians first postulated that sphincter breakdown or bladder weakness caused leaking. But it wasn't until the 1970s, when urodynamic equipment became sophisticated, that urologists began to understand the mechanisms that control voiding.
Today's most popular operations for stress incontinence, have roots in the 1900s and address a common theme: to support the bladder neck and urethral junction so that neither organ sags or leaks. Johns Hopkins's gynecologist Howard Kelly introduced the first plication, or tucking, operation for women in 1914. This colporrhaphy, surgical repair of the vagina, secured the area of the bladder neck with stitches on either side of the urethra. In 1949, a group of specialists, led by urologist Victor F. Marshall, produced the Marshall-Marchetti-Krantz (MMK) procedure, a retropubic suspension of the bladder neck that used an incision in the lower abdomen. Through the incision, urologists stitched the tissue surrounding the bladder neck to the bone or supporting structures. Both the MMK procedure and J.E. Burch's 1961 minimally invasive variation (urethropexy) yielded easy access to immobilize the junction. Another version is the transvaginal approach to bladder suspension—pioneered in 1959 by A.J. Pereyra and since modified by other urologists, including Thomas Stamey, Shlomo Raz and R.F. Gittes. The transvaginal approach involves elevating the bladder neck with sutures placed in the abdominal or pelvic walls.
The powerhouse operation to treat incontinence in women is the pubovaginal sling procedure. This durable technique first lifted the bladder neck using hammock-like strips of surgically transplanted muscles or ligaments. Germany's P. Frangenheim and W. Stoeckel, in 1914 and 1917 respectively, modified the fascial sling technique first introduced by countryman R. Goebell in 1910 to bolster the bladder and urethra. Others would add their own twists, using synthetic, autologous or cadaver material to create the sling. Secured to the abdominal wall or pelvic bone, the sling lifts the urethra into a normal position.
But stress incontinence is not exclusive to females. Dating to early 1900, the approaches to control male incontinence have been legion. In the 1920s, for instance, New York's Oswald S. Lowsley tightened muscles along the male urethra for better constriction.
Yet the bigger milestones involved the use of internal and external devices to compress the urethra or sphincter. The forerunners of today's Cunningham and Baumrucker penile clamps were crude devices that emerged circa 1750 that were used outside the penis to clamp it and constrict the urethra. Nearly two centuries later, in 1947, Minneapolis urologist Frederick E.B. Foley introduced the first artificial sphincter. Patients controlled the artificial sphincter by compressing a pocket device to inflate a pneumatic cuff positioned around surgically segmented portions of the urethra to control the flow of urine.
In 1961, a Veterans Administration urologist in Albany, NY, John Berry, became the first to restore continence by compressing the urethra with implanted acrylic and Silasticª blocks. While early results were encouraging, these devices proved disappointing because they shifted out of place and eroded into the urethra. In 1978, Joseph J. Kaufman, of the University of California, Los Angeles, introduced an implantable silicone-gel "pillow" to cause urethral resistance, based on earlier versions.
But implanted artificial sphincters, the surgical brainchild of Baylor College of Medicine's F. Brantley Scott, soon surpassed the prosthesis. First introduced in 1973, this device would become a viable solution for post-prostatectomy patients suffering from incontinence. Today's model works by keeping the urethra closed until necessary. To empty the bladder, the patient squeezes and releases a scrotum pump, which empties fluid from a sphincter cuff (positioned around the urethra) into a pressure-regulating balloon. With pressure relieved from the urethra, urine flows freely. As the bladder empties, the fluid of the balloon automatically moves back into the cuff, squeezing the urethra shut and preventing leaks.
Surgery is mainly applied to patients with an incompetent urethra. The vast majority of patients suffer from bladder function-related incontinence. Surgery is rarely needed in these cases. Urologists have medications to tap for both genders to expand urine storage, improve bladder emptying or increase sphincter closure and relaxation. Oxybutynin chloride (Ditropan XL) and tolterodine tartrate (Detrol LA) reduce overactive bladders by blocking acetylcholine, the chemical that causes muscle contractions.
These drugs are hardly the end-all. As urologists look forward, they anticipate more effective drugs, delivered in patches, or implantable devices. A bladder pacemaker is used to control overactive bladder.
At the University of Pittsburgh Medical Center, Michael Chancellor and his colleagues are researching the effects stem cells can have on the growth of new tissue in denervated rat sphincters. In the future, it could be possible to rehabilitate "worn-out" sphincters and other organs to restore urologic health without implants, pharmaceuticals or surgery.
Contributors:
Rainer Engel, MD