Aim of Study
Invasive
pressure flow analysis is the gold standard for discriminating
hypocontractile detrusor and infravesical obstruction
in male patients with lower urinary tract symptoms
(1). Previous
studies show it is possible to diagnose infravesical
obstruction on basis of a combination of maximum flow
rate and isovolumetric bladder pressure (2, 3). When an external catheter was utilized it can
occur an elasticity of the condom and damping of the
bladder pressure. The purpose of this study is to
analyze the results of non-invasive isometric bladder
pressure measured by a catheter in the fossa naviculares
of the urethra and compare the results with flow/pressure
study.
Method
Fifty
male patients with lower urinary tract symptoms were
evaluated by flow/pressure study and non-invasive
isometric bladder pressure. A catheter was developed to adapt in the fossa naviculares of the
urethra to avoid leakage during micturation and when
the catheter was occluded. When the catheter was occluded
was possible measured the isometric bladder pressure.
The urinary flow was measured and the isometric
bladder pressure was registered when the catheter
was occluded. In
both study the Abrams Griffith number was utilized
to evaluate bladder outlet obstruction. Kappa coefficient was used for statistical
analysis.
Results
Of
the 50 patients studied, 17 were excluded because
their Abrams Griffiths Number were in dough range
. The statistical results comparing non invasive bladder
pressure to urodynamic evaluation shoed 87% sensitivity,
88% specificity, positive predictive value 93,35 and
negative predictive value of 80%.
Conclusion
Non
invasive isometric bladder pressure analyzed with
urinary flow present very close results to flow/pressure
study and should be used in male patients who presents
lower urinary tract symptoms.
References
-
Validity of a non-invasive determination
of the isovolumetric bladder pressure during voiding
in men with LUTS. Neurourol Urodyn
1999 18 477-486
-
Non-invasive measurement of bladder pressure
using en external catheter. Neurourol Urodyn 1999
18 455-475
-
Non-invasive pressure/flow measurements
for precise grading of bladder outflow obstruction.
J Urol 1994 151 323A
