Comparison of Bladder Contractility Values Estimated with the Non- Invasive Condom Catheter Method and Pressure-flow Studies

Hypothesis / aims of study Bladder contractility is an important parameter in the diagnosis of lower urinary tract dysfunction. Currently, pressure-flow studies are used to assess bladder contractility by combining flow rate and detrusor pressure into one parameter, e.g. Wmax or WQmax. The determination of Wmax and WQmax is based on a theoretical model (1). Using the non-invasive condom catheter method bladder contractility is assessed by measuring the maximum condom pressure, which represents the isovolumetric intravesical pressure. In a recent study, measurements with the non-invasive penile cuff method were used to assess among other things the theoretical model used to calculate Wmax. It was found that there are marked similarities between the experimental model and the theoretical model at high flow rates (2). However, at low flow rates, the experimental data showed lower bladder contractility compared to the theoretical models. Our aim was to compare the bladder contractility estimated with the non-invasive condom catheter method directly to the bladder contractility derived from the invasive pressure-flow studies. In addition, the quality of both methods was assessed by calculating the normalized repeatability (3).