Re: Noninvasive methods to evaluate bladder obstruction in men.

Reading this paper leads to some thoughts. Our main concerns are first that from paragraph “Symptoms” to paragraph “Doppler Resistive Index”, this paper looks like the paper of M. Belal and P. Abrams “Noninvasive methods of diagnosing bladder outlet obstruction in men. Part 1: Nonurodynamic approach” J Urol 2006; 176: 22-8 (not referenced by the authors) and second, more important, that the authors have made a mixture between two methods the condom method (paragraph Measurement using External Catheter (MEC)) and the penile cuff method (paragraph Measurement Using Penile Compression (MUCP)). Some results about penile cuff method are included in the paragraph external catheter and vice versa. About external catheter, the authors mention a good accuracy for weak flow rate while the original paper mention a lack of accuracy if the flow rate is lower than 5.4 mL/s (van Mastright et al. Development and application of the condom catheter for non-invasive measurement of bladder pressure. J Urol 2009; 25: 99-104). The description of penile compression given by the authors is (only) that of the cuff deflation (Mc Rae et al NAU 1995; 14: 101-114 and Gleason et al. NAU 1997; 16: 93-100) which is not used today. The penile cuff method currently used is an inflation-deflation method (C.J. Griffiths et al.); after initiation of voiding, a cuff is progressively inflated at a stepwise increment of 10cm H2O to a maximum of 200 cm H2O until interruption of the flow. Thus many measurements are possible. The surge of flow observed when the cuff is deflated allows calculating a PCR index (see next remark). In addition, some non-invasive methods have been forgotten: the Penile Compression and Release (PCR) from M.P. Sullivan et al. (NAU 1995; 14: 481-3 & NAU 2000; 19: 657-669) allowing calculating a PCR index, and the D index of voiding dysfunction from F.A. Valentini et al. (BJU Int 2008; 101: 995-9) obtained from a modelled analysis of free uroflows.