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What are lower urinary tract symptoms?
LUTS, or lower urinary tract symptoms, is a term
used to describe a range of urinary symptoms and may
include: frequency, urgency, incontinence, nocturia,
dysuria, recurrent urinary tract infection (UTI),
hesitancy, weak stream, and incomplete emptying.
LUTS encompasses dysfunctions in bladder storage,
voiding or both. The
International Prostate Symptom Score
(IPSS) is designed for the assessment and diagnosis of LUTS
and evaluation of treatment outcomes.
Dysfunctions of storage include:
- Bladder capacity
- Bladder compliance
- Overactive bladder (OAB) = Presence of phasic
contractions (also called detrusor instability)
- Urethral incompetence
- Incontinence (urge, stress, mixed)
Dysfunctions in voiding include:
- Bladder neck and urethral function
- Urethral diverticulum
- Vesicoureteral reflux
- Obstruction
- Intrinsic sphincter deficiency
- Detrusor weakness
Urologic Testing
A urologic exam includes detailed patient history, physical
assessment, patient diary (frequency/volume charts),
and urodynamic testing (filling/voiding studies).
Urodynamics is the general term for the study of the storage and
voiding function/dysfunction of the lower urinary
tract. This includes one or more of the following:
- Filling cystometry
- Uroflowmetry
- Flow/pressure study
- Bladder pressure during filling (storage) and voiding
- Obstruction when the pressure in the bladder is high and
the flow rate of urine is low
- Electromyography (EMG): looks at the coordination between bladder
muscle contraction and sphincter relaxation (detrusor sphincter dyssynergia)
- Videocystourethography (VCUG): x-ray imaging
NIRS Approach
The NIRS bladder
monitor system applies near infrared spectroscopy
(NIRS) technology to monitor hemodynamic changes in
the microcirculation of the bladder detrusor muscle
during voiding. This is used to detect characteristic changes
in health and disease, and provides a real-time,
non-invasive evaluation of bladder function to aid
in the diagnosis of bladder outlet obstruction
(BOO). The diagnosis is made with the use of a uroflowmeter
(for measuring the maximum urinary flow
rate, Qmax) and ultrasound devices (for measuring
postvoid residual volume, PVR).
This breakthrough
technology provides urologists with clinically
relevant information about the health and function
of the bladder without the use of invasive
catheter-based tests.
Currently Urodynamix has two systems in use
worldwide:
Tetra™ Bladder Monitor System
is a system developed
by Urodynamix and distributed worldwide by Laborie
Medical Technologies Inc. as an accessory to
Laborie's premium urodynamics equipment.
It allows for the non-invasive monitoring
of bladder function to aid in the diagnosis of BOO.
uroNIRS 2000™
Bladder Monitor System is a
wireless standalone tablet PC-based device
specifically designed for ease of use in the
physician’s office setting. The system is compact and portable.
This non-invasive
NIRS procedure is easier, faster, less expensive and
more comfortable for patients than conventional
invasive urodynamic studies (UDS).It eliminates the use of catheters and the
associated complications, fear, and pain [1], [2],
Clinical studies
have shown that the uroNIRS bladder monitor has 86%
sensitivity and 89% specificity for detecting BOO
compared to conventional UDS [4].
References:
[1] Klingler HC, Madersbacher S, Djavan B,
Schatzl G, Marberger M, Schmidbauer CP. Morbidity of the evaluation of the lower
urinary tract with transurethral multichannel
pressure-flow studies. J Urol. 1998 Jan;
159(1):191-4
[2] Greenstein A, Bar-Yosef Y, Chen J, Matzkin H.
Does information provided to men before a urodynamic
study affect their expectation of pain? BJU Int.
2005 Dec; 96(9):1307-9
[3] Choe JH, Lee JS, Seo JT. Urodynamic studies
in women with stress urinary incontinence:
Significant bacteriuria and risk factors. Neurourol
Urodyn. 2007;26(6):847-51
[4] Macnab AJ, Stothers L. Near-infrared
Spectroscopy: Validation of bladder-outlet
obstruction assessment using non-invasive
parameters. Can J Urol. 2008; 15(5): 4241-4248
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