Pressure/cross-sectional area probe in the assessment of urethral closure function

A probe, which enables measurement of related values of pressure and cross-sectional area, was used for in vitro studies and in vivo measurements in the female urethra. Six healthy females underwent two successive investigations. Measurements were performed at the bladder neck, in the high-pressure zone and distally in the urethra. The in vitro study showed that cross sectional areas of 13–79 mm2 were determined with a SD of 1.4 mm2. In vivo measurements revealed that the urethral parameters: elastance, hysteresis, pressure and power of contraction during coughing and squeezing were fairly reproducible. However, a certain interindividual variation of the parameters was found.