Validity of a non-invasive determination of the isovolumetric bladder pressure during voiding in men with LUTS.
Invasive pressure flow analysis is the gold standard for discriminating between hypocontractile bladder muscle function and infravesical obstruction in male patients with lower urinary tract symptoms. Here a non-invasive method to determine the isovolumetric bladder pressure to judge contractility is presented. This is based on interruption of urine flow by sudden occlusion of a specially fixed condom catheter. The pressure inside the condom is recorded and used to estimate the isovolumetric bladder pressure. Combined with, for example, home uroflowmetry, this non-invasive method may overcome some of the disadvantages (e.g., invasiveness, cost) of the conventional pressure flow test. To determine the isovolumetric bladder pressure reliably with this non-invasive method, two constraints have to be met. First, the bladder neck and urethra have to remain open after occlusion of the condom catheter. This was tested combining the non-invasive test with radiography in five patients. Second, a steady state has to be reached, i.e., the flow in the urethra, due to the elastic properties of the biological and the condom systems, should come to a stop when the bladder pressure and the condom pressure equilibrate. This was investigated by comparing the non-invasively recorded condom pressure with the simultaneously invasively recorded intravesical pressure in 52 patients. In these patients, three different methods of condom fixation were evaluated. The results show that the bladder neck and urethra remain open during the test. However, a steady state is often not reached. In more than 80% of the cases with the best condom fixation, the bladder pressure has not stabilized, although the condom pressure reached a plateau. Therefore, this method of sudden occlusion is not yet clinically applicable for determining the isovolumetric bladder pressure. Neurourol. Urodynam. 18:477-486, 1999.
Gommer
E D
ED
Department of Urology, Maastricht University Hospital, Maastricht, The Netherlands.
Vanspauwen
T J
TJ
Miklosi
M
M
Wen
J G
JG
Kinder
M V
MV
Janknegt
R A
RA
van Waalwijk van Doorn
E S
ES
D006801:Humans; D008297:Male; D001743:Urinary Bladder / Q000503:physiopathology*; D014563:Urodynamics; D014570:Urologic Diseases / Q000503:physiopathology; D014572:Urology / Q000295:instrumentation / Q000379:methods*