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Outlet Resistance (outlet + resistance)

Distribution by Scientific Domains
Medical Sciences100%

Kinds of Outlet Resistance

  • bladder outlet resistance
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    Selected Abstracts

    Urodynamic evaluation of the human bladder response tgo an increase in outlet resistance

    NEUROUROLOGY AND URODYNAMICS, Issue 6 2002
    Jason D. Engel
    Abstract Aim. We prospectively evaluated the response of the human bladder to a chronic increase in urethral resistance according to the indices of pressure, volume flow rate, total (external) bladder work, and maximum and average detrusor power. Methods. Six men with incontinence after radical prostatectomy were evaluated urodynamically before and 3,6 months after undergoing a bulbourethral sling procedure. Results. None of the men suffered from significant obstructive or irritative voiding symptoms preoperatively. Urodynamic evaluation showed postoperative increases in both average detrusor pressure and pressure at maximum flow, but there were no significant changes in voided volume, void time, or postvoid residual urine volume. Maximum detrusor power, average detrusor power, and total (external) bladder work were all significantly increased. Conclusion. These data confirm that the human bladder possesses a functional reserve, which is elicited by an increase in urethral resistance. Neurourol. Urodynam. 21:524,528, 2002. © 2002 Wiley-Liss, Inc. [source]

    Is detrusor hypertrophy in women associated with voiding dysfunction?

    AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 6 2009
    Orawan LEKSKULCHAI
    Background:, In men, bladder wall thickness ,5 mm seems to be a useful predictor of outlet obstruction, with a diagnostic value exceeding that of free uroflowmetry indices. There are no data in the literature examining whether this may also apply in women. Aims:, To identify the relationships between detrusor wall thickness (DWT) and symptoms and urodynamic findings suggestive of voiding dysfunction. Methods:, This is a retrospective study analysing data sets of 686 women seen for urodynamic testing in a tertiary urogynaecological unit. Hesitancy, poor stream and stop,start voiding were recorded as symptoms of voiding dysfunction. All women underwent free uroflowmetry and multichannel urodynamic testing. We used the urethral resistance factor (URA) and the obstruction coefficient (OCO), methods employed to quantify bladder outlet resistance in men. Transperineal ultrasound for DWT was performed after voiding and catheter removal. Statistical analysis was carried out by using the statistical software (spss 15.0; SPSS Inc., Chicago, IL, USA). Results:, Symptoms of voiding dysfunction were reported by 33.1% of patients and 22.4% had urodynamically diagnosed voiding dysfunction. The mean DWT in symptomatic women was not statistically different from the mean DWT in those without symptoms. URA and OCO of symptomatic women were significantly different from those of asymptomatic women (P < 0.01). DWT was not associated with parameters of voiding function, URA or OCO. Conclusions:, Contrary to the situation in men, increased DWT in women does not seem to be associated with symptoms or signs of voiding dysfunction. Therefore, DWT cannot be used as a predictor of voiding difficulty in women. [source]

    A porcine model of bladder outlet obstruction incorporating radio-telemetered cystometry

    BJU INTERNATIONAL, Issue 1 2007
    Matthew B. Shaw
    OBJECTIVE To present a novel porcine model of bladder outlet obstruction (BOO) with a standardized bladder outlet resistance and real-time ambulatory radio-telemetered cystometry, as BOO is a common condition with many causes in both adults and children, with significant morbidity and occasional mortality, but attempts to model this condition in many animal models have the fundamental problem of standardising the degree of outlet resistance. MATERIALS AND METHODS BOO was created in nine castrated male pigs by dividing the mid-urethra; outflow was allowed through an implanted bladder drainage catheter containing a resistance valve, allowing urine to flow across the valve only when a set pressure differential was generated across the valve. An implantable radio-telemetered pressure sensor monitored the pressure within the bladder and abdominal cavity, and relayed this information to a remote computer. Four control pigs had an occluded bladder drainage catheter and pressure sensor placed, but were allowed to void normally through the native urethra. Intra-vesical pressure was monitored by telemetry, while the resistance valve was increased weekly, beginning with 2 cmH2O and ultimately reaching 10 cmH2O. The pigs were assessed using conventional cystometry under anaesthesia before death, and samples conserved in formalin for haematoxylin and eosin staining. RESULTS The pigs had radio-telemetered cystometry for a median of 26 days. All telemetry implants functioned well for the duration of the experiment, but one pig developed a urethral fistula and was excluded from the study. With BOO the bladder mass index (bladder mass/body mass × 10 000) increased from 9.7 to 20 (P = 0.004), with a significant degree of hypertrophy of the detrusor smooth muscle bundles. Obstructed bladders were significantly less compliant than control bladders (8.3 vs 22.1 mL/cmH2O, P = 0.03). Telemetric cystometry showed that there was no statistically significance difference in mean bladder pressure between obstructed and control pigs (4.8 vs 6.7 cmH2O, P = 0.7), but that each void was longer in the pigs with BOO. CONCLUSION This new model of BOO provides a method of reliably and precisely defining the bladder outlet resistance; it induces the changes classically seen with BOO, including increased bladder mass, increased smooth muscle bundle size and decreased compliance. [source]

    Colpo-wrap: a new continence procedure

    BJU INTERNATIONAL, Issue 7 2005
    Thomas M. Boemers
    OBJECTIVE To present a new surgical method to increase bladder outlet resistance for the treatment of urinary incontinence in girls and women. PATIENTS AND METHODS Six patients (mean age 9.6 years), with urinary incontinence were operated using the new technique within the last 3 years. The principle of the procedure is tightening of the bladder neck by mobilizing the anterior vaginal wall and wrapping it around the bladder neck and proximal urethra, in the sense of a vaginoplication (colpoplication). The underlying conditions and causes for urinary incontinence was neurogenic bladder-sphincter dysfunction caused by myelodysplasia in three girls and anorectal malformation combined with a tethered spinal cord in one. In one case incontinence was caused by a cloacal anomaly and one girl had intrinsic sphincter insufficiency after repetitive Otis urethrotomies. The colpo- wrap was combined with a bladder augmentation and Mitrofanoff in three patients, the three other girls undergoing isolated procedures. RESULTS The result of the method is a constant increase in outlet resistance and coaptation of the urethra, comparable with the effect of a vaginal sling procedure. Five patients are completely dry after surgery, one girl with cloaca needed an additional bladder neck injection with hyaluranon/dextranomer copolymer. Transurethral catheterization was possible after surgery with no problems in all patients who required intermittent catheterization. CONCLUSION Considering the feasibility of this technique the colpo-wrap is a reasonable alternative for treating urinary incontinence in females. [source]