The promise of urethral pressure reflectometry: an update.

Abstract

The urethral closure mechanism in women is incompletely understood. Measuring closure function in a collapsed urethral tube without distending the tube and changing its natural shape is impossible with conventional methods. Over the last decade, studies with urethral pressure reflectometry (UPR), a method that measures pressure and the corresponding cross-sectional area along the entire length of the urethra continuously by means of acoustic reflectometry, have been performed. The studies have mainly been performed on patients with stress urinary incontinence (SUI). Our aim was to provide an overview of the studies conducted with UPR, establishing whether the method may be used in clinical practice. We reviewed all literature published on UPR. Urethral pressure reflectometry is easily performed with limited bother for the patient. The catheter consists of a 45-cm-long PVC tube connected to a thin and highly flexible polyurethane bag, which is placed in the urethra. When inserted, the bag only occupies 0.4mm(2) of the urethra, respecting the natural shape and orientation of the urethra and, most importantly; respecting the laws of physics when measuring urethral pressure. UPR can discriminate patients with SUI from continent women and separate assessment of the sphincter function and support system is possible. Also, UPR has revealed statistically significant differences in urethral pressures after drug therapy for SUI. We conclude that UPR has a place in clinical practice. The method has shown groundbreaking potential in the understanding of urethral dysfunction in SUI patients.