Method for evaluation of the urethral closure mechanism in women during standardised changes of cross-sectional area.

A method for evaluation of the closure mechanism in the female urethra during forced opening has been developed and tested. The cross-sectional area (CA) of the tube and the intraluminal pressure were measured simultaneously by a specially designed balloon catheter. The method enables induction of standardised changes of CA at different rates. Applied in the female urethra the induction results in a distinct pressure response which increases with increasing rate of change of CA as well as size of the induction. The inflation of the balloon simulates a forced opening of the urethra and hence leakage. Obviously, urinary incontinence takes place at forced opening of the urethra. Accordingly, this novel method can give important information on the pathophysiology of stress urinary incontinence in particular and the physiology of sphincter functions in general.