Positioning invasive versus noninvasive urodynamics in the assessment of bladder outlet obstruction

Abstract

To provide evidence of promising tests to noninvasively diagnose bladder outlet obstruction (BOO) in men with benign prostatic hyperplasia. Pressure-flow studies are usually performed to prove BOO prior to prostatectomy. However, pressure-flow studies are invasive, expensive, time consuming, and potentially harmful to the patient due to unwarranted side-effects. In the last decade, attempts were made to diagnose BOO noninvasively. Ultrasound-derived measurements such as bladder or detrusor wall thickness or intravesical prostatic protrusion and urodynamic-derived measurements such as isovolumetric bladder pressure by the condom catheter or penile cuff tests show promising results. Likelihood ratios of all tests were calculated for this study and indicated a good ability to detect BOO. Noninvasive measurements of bladder/detrusor wall thickness, intravesical prostatic protrusion, or isovolumetric bladder pressure might replace invasive pressure-flow studies in the future if only information about BOO is needed. These tests are applicable for the majority of patients with lower urinary tract symptoms and suspected BOO. However, urodynamic investigations are still indicated in patients requiring detailed information about the bladder filling and voiding phases and to assess the precise cause of lower urinary tract symptoms.