Assessment of prostatic obstruction: A cuff may be enough

Aims: To investigate the use of an inflatable perile cuff to obstruct flow progressively during voiding in order to provide a noninvasive measure of bladder pressure. Methods: In this study, we explain the observed relationship of flow rate with applied cuff pressure by analogy with a simple physical model. The model comprised a fixed-pressure reservoir (simulating the bladder), a collapsible tube around which a fixed pressure could be applied (simulating the prostatic urethra), connected by rigid conduit to a further collapsible tube around which pressure could be applied (simulating the penile urethra and cuff). Flow was progressively obstructed by incremental increase of pressure applied to the "penile urethra," with the experiment being repeated for a range of fixed pressures applied to the "prostatic urethra." Results: The model reproduced the typical pressure/flow curves recorded during voiding by using penile cuff inflation in normal and obstructed men. Conclusions: Our data led us to hypothesise that the relationship between cuff pressure and flow rate can be used to deduce bladder pressure during voiding, prostatic opening pressure, and urethral diameter at the flow-controlling zone, three indicators of lower urinary tract function. These measurements may add to the accuracy of diagnosis and quality of care for a large number of men with lower urinary tract symptoms. (C) 2003 Wiley-Liss, Inc.