Distal urethral compensatory mechanisms in women with an incompetent bladder neck who remain continent, and the effect of the menopause

摘要

AbstractFemale continence is thought to be maintained at the level of the bladder neck and by the external sphincter. However, many women have an incompetent bladder neck, that is their bladder neck opens under stress. However, they still remain continent, presumably by use of their distal external sphincter. To establish the effect of age and the menopause on this phenomenon, data from 202 climacteric urodynamically normal and continent women were examined. The overall prevalence of videocystourethographically diagnosed bladder neck incompetence in these women was 51 ± 4. The median age in this group was 50.4 years but the prevalence of bladder neck incompetence in women below 50.4 years was not significantly different from older women (>50.4 years) being 49 ± 5 and 53 ± 5, respectively. Of the 202 women studied the prevalence of bladder neck incompetence in perimenopausal women was 54 ± 5 and 48 ± 5 in postmenopausal women, there being no statistically significant difference between the two subgroups separated on the basis of their estrogen status. These data do not support the contention that bladder neck integrity is estrogen dependent nor is there any evidence from these data that is it age dependent. To understand how women with bladder neck incompetence maintain continence, 55 of the 202 women also underwent urethral pressure profilometry. Bladder neck incompetence results in a proximal shortening of the stress urethral pressure profile but these women maintained their stress urethral functional length by decreased distal shortening of the stress profile. In other words, they made more use of the distal portion of the urethra. This is achieved by augmentation of their distal transmission pressure ra