An anatomical classification--a new paradigm for management of urinary dysfunction in the female.

A new classification specifies anatomical defects in the anterior, middle and posterior zones of the vagina as causing urinary dysfunction. An external musculoelastic mechanism stretches the vagina to open and close the outflow tract. The same pelvic floor muscles provide a peripheral control mechanism for micturition. The stretched vagina prevents the filling bladder from activating the stretch receptors. Vaginal laxity may weaken the transmission of muscle forces, interfering with the mechanical process of opening and closure. Laxity may also destabilize the peripheral control mechanism, a neurological process, causing bladder control to swing between the open and closed modes, i.e. bladder instability. Specific symptoms, signs and urodynamic tests were arranged into a pictorial algorithm as a practical guide for locating the three zones of anatomical defects. It was possible to reinterpret almost all the definitions and descriptions of the International Continence Society in terms of this classification, and to explain how vaginal laxity may cause premature activation of the micturition reflex (detrusor instability), stress incontinence and abnormal emptying (dribble, overflow). This convergence in anatomical and urodynamic (ICS) concepts explains many previously unexplained phenomena, and potentially opens up an entirely new approach to management, non-surgical strengthening of specific ligaments, or surgical reinforcement thereof with ambulatory 'keyhole' methods which do not require catheterization.