Observations on the function of the female urethra: II: Relation between maximum urethral closure pressure at rest and the degree of urethral incompetence.

Aims: To study the relation between maximum urethral closure pressure (MUCP) at rest and the degree of urethral. incompetence in the female. Patients and Methods: Two hundred fifty five patients aged 20 years or older, with stable bladders on multichannel urodynamics, without known neurological pathology, and with no previous history of pelvic or anti-incontinence surgery were included in the study. Resting urethral pressure profile (UPP) and the grade of urethral incompetence was registered. Results: Mean age of the group was 45.6 +/- 12.7 years; mean MUCP was 62.7 +/- 28.5 cm of water. There was a statistically significant difference in the MUCP when the different grades of urethral incompetence were compared to each other, the higher grades being associated with a lower maximal closure pressure. Conclusions: This study demonstrates that there is a highly significant relationship between MUCP and between all grades of urethral incompetence. This supports previous observations that MUCP decreases when abdominal leak point pressure (ALPP) is low and that this might be secondary to some mechanical failure in the pressure transmission from the abdominal cavity to the urethra. Studies should never compare continent to incontinent cohorts without considering their ALPP because in doing so they are comparing groups that are functionally heterogeneous. (C) 2003 Wiley-Liss, Inc.