Pressure transmission to the pre-urethral space in stress incontinence.

Pressure transmission from the abdomen to the pre-urethral space has been studied in stress- incontinent women and in some women following pubococcygeal repair for stress incontinence. Pressure was recorded at different levels of the pre-urethral space and simultaneously in the bladder. Simultaneous measurements inside and outside the urethra at different levels above the external urethral meatus showed that an intra-abdominal pressure rise was transmitted via the pre-urethral space to the urethra. Pressure was transmitted almost in full to the surroundings of the lower-most part of the bladder, but outside the functional urethra, transmission was successively more defective along the urethra towards the external meatus. Therefore, a short functional length and a distal maximal pressure plateau in the urethra, as in stress incontinence, is a disadvantage. Pressure losses amount to 1/3 or more. Pressure transmission could be improved to "supranormal" values by establishing firm support for the urethra, thereby allowing a minimum of rotational descent with stress and providing good counterpressure.