Cystometry, Pressure Flow Study and Urethral Pressure Measurement

Abstract

Cystometry, pressure flow study (PFS) and urethral pressure profile (UPP) are core contents of paediatric urodynamic studies (PUDS) which are becoming an increasingly popular tool to evaluate the lower urinary tract dysfunction (LUTD)/lower urinary tract symptoms (LUTS) in children with congenital or acquired malformations such as neurogenic bladder, vesicoureteric reflux, urinary tract infection, urge syndrome, nocturnal enuresis, urinary incontinence and anorectal malformations. The aims of these tests are to reproduce symptoms, to identify the underlying causes for symptoms and to quantify related pathophysiological processes. Cystometry is mainly used to evaluate bladder function of the filling phase and PFS for voiding phase. UPP is used to monitor urethral function (sphincter function), but its clinical application is limited. Instead, simultaneous bladder and urethral pressure measurement for evaluating urethral dynamic function is encouraging. However, it must be realized these studies are invasive and artefacts may occur and influence the correct interpretation of the results. Infants and children have a different spectrum of bladder dysfunctions from adults and are generally much less cooperative during a urodynamic study. The normal urodynamic parameters, such as bladder capacity, change with age. Therefore, cystometry, PFS and UPP operation need more gentle, and results interpretation need more carefully. This chapter will introduce how to perform the procedures, and emphasis will be placed on correctly setting up the equipment according to ICS and ICCS guidelines, correct terminology, indications for performing, as well as how to interpret results. Cystometry in combination with fluoroscopy which is referred to as a video-urodynamic study will not be covered in this report.