ELIMINATION OF THE INFLUENCE OF INTRAVESICAL PRESSURE ON THE MICTURITIONAL URETHRAL PRESSURE PROFILE BY CALCULATION OF URETHRAL CROSS-SECTIONAL AREA - AN EXPERIMENTAL-STUDY

Objective To determine whether it is possible to eliminate the influen ce of intravesical pressure on the pressure drop recorded between the bladder and prostatic urethra during the micturitional urethral pressu re profile (MUPP). Materials and methods An experimental study using a n artificial bladder/urethral model and computerized urethral pressure profile measurement system. Results By simultaneous measurement of th e flow rate and MUPP it is possible to calculate a theoretical cross-s ectional area, based on Griffiths' theory of flow through distensible tubes. The calculated cross-sectional area for a given constriction re mains the same despite changes in the driving pressure. Conclusion The effect of changes in intravesical pressure on the MUPP can be elimina ted by calculation of the urethral cross-sectional area. This paramete r forms part of the Schafer model of obstruction and this technique ma y therefore be useful in quantifying bladder outlet obstruction.