Noninvasive measurement of bladder pressure by controlled inflation of a penile cuff.
OBJECTIVE
A noninvasive test providing reliable objective quantification of bladder pressure during the voiding cycle would make an important contribution to the management of lower urinary tract symptoms. We developed a new noninvasive test to measure bladder pressure in males based on controlled inflation of a penile cuff during voiding. We compared the new technique with simultaneous invasive bladder pressure measurement.


METHODS
We evaluated 7 volunteers and 32 patients. A conventional pressure flow study was performed first. The bladder was refilled, a penile cuff was fitted and after voiding commenced the cuff was inflated in steps of 10 cm. water every 0.75 seconds until urine flow was interrupted. The cuff was rapidly deflated, allowing flow to resume, and the cycle was repeated until the end of voiding. The flow rate was graphed against cuff pressure for each interruption cycle to determine the pressure at which flow was interrupted. This pressure was compared with simultaneous invasive isovolumetric bladder pressure.


RESULTS
Invasive and noninvasive pressure measurements agreed well. Average cuff pressure at interruption of flow exceeded mean simultaneous isovolumetric bladder pressure plus or minus standard deviation by 14.5 +/- 14.0 cm. water.


CONCLUSIONS
The new method provides noninvasive quantitative information on voiding bladder pressure in males. Further study is required to assess whether the technique can contribute to the management of lower urinary tract symptoms.
Griffiths
C J
CJ
Regional Medical Physics Department and Department of Urology, Freeman Hospital, Newcastle upon Tyne, United Kingdom.
Rix
D
D
MacDonald
A M
AM
Drinnan
M J
MJ
Pickard
R S
RS
Ramsden
P D
PD
D000328:Adult; D006801:Humans; D008297:Male; D008875:Middle Aged; D010413:Penis / Q000502:physiology; D011312:Pressure; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination / Q000502:physiology*; D014563:Urodynamics; D014572:Urology / Q000295:instrumentation