[Urinary stress incontinence in the female: comparison of incontinence theories and new tension-free surgical procedures].

Urethral sphincter competence involves a complicated inter action of many factors which act in concert. Stress incontinence occurs due to damage to the urethral support and loss or deterioration of urethral sphincter function as a consequence of delivery or aging. Recent research indicates that a more integrated, comprehensive view regarding the different structures, both inside and outside the urethra, is needed to explain the mechanism of incontinence. According to the theories of de Lancey, urinary stress incontinence is caused by defects in the supporting tissues that both actively and passively stabilize the urethra in its correct anatomical position. The integral theory of Petros and Ulmstein explains how laxity in the vagina or its supporting ligaments may cause stress incontinence favored by laxity in the ligamentous insertion points of the vagina. Colposuspension procedures have dominated incontinence surgery for the last 50 years. The introduction of the tension-free vaginal tape procedure was a real innovation that has challenged our understanding of the continence mechanism and taught us the importance of the midurethra. Different modifications of the tension-free procedures have been introduced recently and are discussed in this paper.