Urinary incontinence and the artificial urinary sphincter

Urinary incontinence, as defined by the International Continence Society, is the complaint of involuntary leakage of urine. It is one of the most common medical problems affecting both men and women and can be a source of significant hygienic and psychosocial burden for patients.Large population surveys have found that over 40% of women have some degree of urinary incontinence. [1, 2] The prevalence in men is lower (14-32%), but more common than previously thought. [3-7] Studies have also shown that the prevalence of urinary incontinence also increases with age. [1, 8] There are several types of urinary incontinence. Stress incontinence is the involuntary loss of urine with physical exertion, coughing or sneezing. Urge incontinence is the involuntary loss of urine accompanied by, or immediately preceded by, a sudden desire to urinate (urgency). Mixed incontinence is where the symptoms of stress and urgency coexist. Finally, overflow incontinence is the leakage of urine associated with urinary retention. The focus of this chapter is on the mechanism of action of the human urinary sphincter, problems that can cause sphincter dysfunction leading to stress urinary incontinence, and surgical therapies to help augment a deficient urinary sphincter to restore continence, with particular emphasis on the artificial urinary sphincter. Newer, alternative treatments will also be discussed.