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Dive into the research topics where B. Clarke is active.

Publication


Featured researches published by B. Clarke.


Ultrasound in Obstetrics & Gynecology | 2005

Biometry of the pubovisceral muscle and levator hiatus by three‐dimensional pelvic floor ultrasound

Hans Peter Dietz; C. Shek; B. Clarke

Until recently, magnetic resonance was the only imaging method capable of assessing the levator ani in vivo. Three‐dimensional (3D) ultrasound has recently been shown to be able to demonstrate the pubovisceral muscle. The aim of this study was to define the anatomy of the levator hiatus in young nulliparous women with the help of 3D ultrasound.


International Urogynecology Journal | 2001

The use of perineal ultrasound to quantify levator activity and teach pelvic floor muscle exercises.

Hans Peter Dietz; P. D. Wilson; B. Clarke

Abstract: Perineal ultrasound was used to detect and quantify levator activity by measuring the displacement of the internal urethral meatus against the inferoposterior margin of the symphysis pubis. Women who had previously been instructed in pelvic floor muscle exercises were more likely to contract the levator muscle when asked to do so than were those without previous instruction (P<0.0001). Of the 56 women who were unable to contract the pelvic floor on request, 32 (57%) eventually succeeded with visual ultrasound biofeedback. Pelvic floor muscle assessment and teaching can be used as an adjunct to the ultrasound assessment of urogynecologic patients, requiring at most 5 minutes. It allows quantification of lavator activity and can provide visual biofeedback, which is easily understood and readily accepted by women.


International Urogynecology Journal | 2002

Bladder Neck Mobility and Urethral Closure Pressure as Predictors of Genuine Stress Incontinence

Hans Peter Dietz; B. Clarke; Peter Herbison

Abstract Two hundred and seventy-five consecutive patients with symptoms of lower urinary tract dysfunction underwent urodynamic evaluation, including multichannel urodynamics, urethral pressure profilometry, X-ray and ultrasound imaging. After women with previous incontinence or prolapse surgery or pelvic radiotherapy and those with evidence of urethral kinking on ultrasound had been excluded, 179 datasets were analyzed. Both bladder neck descent (P<0.0001) and maximum urethral closure pressure (P<0.0001) were strongly associated with a fluoroscopic diagnosis of GSI. Only weak correlations between bladder neck mobility and urethral pressure parameters (highest r=−0.17) were observed. Regression analysis yielded a mathematical model that demonstrated a wide spread of odds ratios for GSI for the measured values (from <0.2 to >100). Bladder neck descent explained 29% and urethral closure pressure 12% of overall variability. Both bladder neck mobility and maximum urethral closure pressure are strong predictors of the diagnosis of GSI, provided major confounders are excluded. Bladder neck mobility appears to be the stronger predictor.


British Journal of Obstetrics and Gynaecology | 2005

Bladder neck mobility is a heritable trait

Hans Peter Dietz; Narelle K. Hansell; M. Grace; Ann Eldridge; B. Clarke; Nicholas G. Martin

Objective  Congenital connective tissue dysfunction may partly be responsible for female pelvic organ prolapse and urinary incontinence. We undertook a heritability study to determine whether mobility of the bladder neck, one of the main determinants of stress urinary incontinence, is genetically influenced.


International Urogynecology Journal | 2001

The Urethral Pressure Profile and Ultrasound Imaging of the Lower Urinary Tract

Hans Peter Dietz; B. Clarke

Abstract: In a prospective study 105 patients with symptoms of stress incontinence underwent videourodynamic testing, including resting urethral pressure profilometry and translabial ultrasound. The urethral pressure profile (UPP) included maximum urethral closure pressure (MUCP), functional length (FL) and area under the curve (AUC). Ultrasound parameters included urethral thickness, urethral rotation and bladder neck descent, as well as funneling/opening of the internal urethral meatus on Valsalva maneuver. Levator contraction strength was assessed measuring the cranioventral displacement of the internal meatus. Negative correlations between UPP data and age, parity and previous surgery were observed which were consistent with literature data. There was a positive correlation between the urethral AP diameter on ultrasound and the MUCP, which agrees with reports showing reduced sphincter thickness or volume in stress-incontinent women. Hypermobility on ultrasound did not correlate with UPP data. However, a lower MUCP correlated with extensive opening of the bladder neck. Finally, there was a trend towards poorer pelvic floor function with lower MUCP measurements.


Australian & New Zealand Journal of Obstetrics & Gynaecology | 2005

Prevalence of rectocele in young nulliparous women

Hans Peter Dietz; B. Clarke

Background:  It is generally assumed that fascial defects in the rectovaginal septum are the result of childbirth. However, rectoceles do occur in women who have never delivered vaginally.


International Urogynecology Journal | 2001

The influence of posture on perineal ultrasound imaging parameters.

Hans Peter Dietz; B. Clarke

Abstract: A prospective clinical study was carried out to evaluate the influence of posture on perineal ultrasound imaging parameters. One hundred and thirty-two consecutive women presenting with symptoms of lower urinary tract dysfunction were examined by multichannel videourodynamics and perineal ultrasound, both supine and standing. Ultrasound included color Doppler imaging when available, i.e. in a subgroup of 99 patients. The position of the bladder neck at rest was higher in the supine position (P<0.001) and it descended further on Valsalva (P<0.001), to reach an almost identical final position. There was a higher degree of urethral rotation on supine imaging (P= 0.001). Urethral funneling on Valsalva was more likely in the erect position (P<0.001), as was urine leakage documented by color Doppler imaging (P<0.001). The effect of a pelvic floor contraction was not significantly influenced by posture. Imaging of the urethrovesical junction should be undertaken in both supine and erect positions to document optimally both hypermobility and funneling or leakage.


International Urogynecology Journal | 1997

The role of urodynamic assessment in the diagnosis of lower urinary tract disorders

B. Clarke

The relationship between clinical symptomatology and urodynamic findings was studied prospectively in 1000 unselected women with symptoms of lower urinary tract dysfunction. Women in the study were subjected to both clinical and multichannel urodynamic assessment. The symptom of stress incontinence was confirmed by urodynamic assessment to be associated with genuine stress incontinence (95%). However, it was also associated with sensory urgency (96%) and detrusor instability (64%). Other lower urinary tract symptoms were associated with a range of abnormal urodynamic findings. It was concluded that urodynamic assessment provided useful information in women with lower urinary tract disorders, in developing principles of diagnosis and management.


Australian & New Zealand Journal of Obstetrics & Gynaecology | 2004

Does pregnancy affect pelvic organ mobility

Hans Peter Dietz; Ann Eldridge; M. Grace; B. Clarke

Background: It is generally accepted that parity is a strong predictor of pelvic organ prolapse and incontinence. However, controversy persists as to whether this effect is due to pregnancy itself or parturition.


Twin Research | 2004

Genetic Covariation of Pelvic Organ and Elbow Mobility in Twins and Their Sisters

Narelle K. Hansell; Hans Peter Dietz; Susan A. Treloar; B. Clarke; Nicholas G. Martin

A range of environmental risk factors, with childbirth the most notable, have been associated with the development of pelvic organ prolapse and urinary incontinence. However, indications of genetic influence (positive family histories, ethnic differences) have prompted research into the heritability of measures of pelvic organ descent and joint mobility, which have also been associated with prolapse and incontinence. Genes appear to influence about half of the variation in these measures and, furthermore, the pelvic organ measures are associated with elbow hyperextension at a phenotypic level (r approximately .2). We examined these measures in young, nulligravid women to determine if their association is due to a common genetic source. Data were collected from 178 Caucasian female co-twins and non-twin sisters, 50 of whom returned to be retested, which allowed reliability to be estimated and unreliable variance to be isolated in the multivariate analyses. Structural equation modeling was used to estimate genetic associations between latent elbow and bladder mobility factors for which heritabilities were estimated to be 0.80 and 0.64 respectively. The association between these factors appeared to be mediated by common genes (genetic r = .48, non-shared environmental r = -.06), with genes influencing latent elbow mobility accounting for 14% of the variation in latent bladder mobility. We speculate that genes influencing connective tissue structure may underlie this association.

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Ann Eldridge

QIMR Berghofer Medical Research Institute

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M. Grace

QIMR Berghofer Medical Research Institute

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Nicholas G. Martin

QIMR Berghofer Medical Research Institute

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Bernard T. Haylen

University of New South Wales

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H. P. Dietz

St. Vincent's Health System

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