The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Hannchorng Kuo - One of the best experts on this subject based on the ideXlab platform.
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The therapeutic effects and pathophysiology of botulinum toxin a on voiding dysfunction due to Urethral Sphincter dysfunction
Toxins, 2019Co-Authors: Yao Lin Kao, Kuan Hsun Huang, Hannchorng KuoAbstract:Neurogenic and non-neurogenic Urethral Sphincter dysfunction are common causes of voiding dysfunction. Injections of botulinum toxin A (BoNT-A) into the Urethral Sphincter have been used to treat Urethral Sphincter dysfunction (USD) refractory to conventional treatment. Since its first use for patients with detrusor Sphincter dyssynergia in 1988, BoNT-A has been applied to various causes of USD, including dysfunctional voiding, Fowler’s syndrome, and poor relaxation of the external Urethral Sphincter. BoNT-A is believed to decrease Urethral resistance via paralysis of the striated Sphincter muscle through inhibition of acetylcholine release in the neuromuscular junction. Recovery of detrusor function in patients with detrusor underactivity combined with a hyperactive Sphincter also suggested the potential neuromodulation effect of Sphincteric BoNT-A injection. A large proportion of patients with different causes of USD report significant improvement in voiding after Sphincteric BoNT-A injections. However, patient satisfaction might not increase with an improvement in the symptoms because of concomitant side effects including exacerbated incontinence, urinary urgency, and over-expectation. Nonetheless, in terms of efficacy and safety, BoNT-A is still a reasonable option for refractory voiding function. To date, studies focusing on Urethral Sphincter BoNT-A injections have been limited to the heterogeneous etiologies of USD. Further well-designed studies are thus needed.
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therapeutic effects of botulinum toxin a via Urethral Sphincter injection on voiding dysfunction due to different bladder and Urethral Sphincter dysfunctions
Toxins, 2019Co-Authors: Yukhun Lee, Hannchorng KuoAbstract:Botulinum toxin A (BoNT-A) Urethral Sphincter injections have been applied in treating voiding dysfunction but the treatment outcome is not consistent. This study analyzed treatment outcomes between patients with different bladder and Urethral Sphincter dysfunctions. Patients with refractory voiding dysfunction due to neurogenic or non-neurogenic etiology were treated with Urethral Sphincter 100 U BoNT-A injections. The treatment outcomes were assessed by a global response assessment one month after treatment. The bladder neck opening and urodynamic parameters in preoperative videourodynamic study were compared between successful and failed treatment groups. A total of 80 non-neurogenic and 75 neurogenic patients were included. A successful outcome was noted in 92 (59.4%) patients and a failed outcome in 63 (40.6%). The treatment outcome was not affected by the gender, voiding dysfunction subtype, bladder dysfunction, or Sphincter dysfunction subtypes. Except an open bladder neck and higher maximum flow rate, no significant difference was noted in the other variables between groups. Non-neurogenic patients with successful outcomes had a significantly higher detrusor pressure, and patients with neurogenic voiding dysfunction with successful results had higher maximum flow rates and smaller post-void residuals than those who failed the treatment. However, increased urinary incontinence was reported in 12 (13%) patients. BoNT-A Urethral Sphincter injection is effective in about 60% of either neurogenic or non-neurogenic patients with voiding dysfunction. An open bladder neck during voiding and a higher maximum flow rate indicate a successful treatment outcome.
Vik Khullar - One of the best experts on this subject based on the ideXlab platform.
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Urethral Sphincter volume and urodynamic diagnosis
International Urogynecology Journal, 2020Co-Authors: Roopali Karmarkar, Alex Digesu, Ruwan Fernando, Vik KhullarAbstract:Aim To compare Urethral Sphincter measurements in women with different urodynamic diagnoses using three-dimensional transperineal ultrasound (TPU). Methods Women with lower urinary tract dysfunction having urodynamic studies (UDS) were prospectively recruited to this study. A detailed history and vaginal examination were conducted. Saline cystometry was performed and the women were divided into groups according to their urodynamic diagnosis, which were nondiagnostic urodynamics (NUDS), pure detrusor overactivity (PureDO), pure urodynamic stress incontinence (PureUSI) and mixed urinary incontinence (MUDS). Three-dimensional TPU was performed to measure total Urethral Sphincter volume, striated Sphincter volume, core volume, Sphincter length and maximum cross-sectional area. The ultrasound measurements were compared with the diagnostic urodynamics. Results One hundred fifty women were included in the study. There were 37, 53, 22 and 38 women in the groups of NUDS, PureDO, PureUSI and MUDS respectively. The average striated Sphincter volumes in these groups were 1.84 ml, 2.24 ml, 1.32 ml and 1.98 ml respectively. There was no difference in average age, body mass index or presence of prolapse in these groups. All measurements were larger in the PureDO and smaller in the PureUSI group compared with the NUDS group. The measurements in the MUDS group were larger than in the NUDS group and smaller than in the PureDO group but this difference was not statistically significant. Conclusion The Urethral Sphincter of women with PureDO is larger than in women with PureUSI. The value in women with MUDS was between the two. The size of the Urethral Sphincter appears to be related to the pathophysiology.
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three dimensional ultrasound of the Urethral Sphincter predicts continence surgery outcome
Neurourology and Urodynamics, 2009Co-Authors: Alessandro G Digesu, Linda Cardozo, Dudley Robinson, Vik KhullarAbstract:Aim To assess the predictive value of three-dimensional (3D) ultrasound volumes of the Urethral Sphincter in women undergoing continence surgery. Materials and Methods Women with urodynamic stress incontinence undergoing to Burch colposuspension were prospectively studied using videocystourethrography (VCU), Urethral pressure profilometry (UPP) and a 3D transvaginal ultrasound scan of the urethra. The total Urethral Sphincter volume, Urethral volume, maximum cross sectional area, and rhabdoSphincter volume were calculated, preoperatively. Surgical outcome was assessed at 6 months using VCU. Urethral function parameters were correlated to surgical outcomes using the Mann–Whitney U-test. Results Ninety-one women were studied. Women who failed continence surgery had significantly smaller preoperative Urethral Sphincter volumes than those who had an objective cure (P < 0.001). UPP parameters were not found to be predictive of surgical outcome (P = 0.5). Conclusions The assessment of the Urethral Sphincter using a 3D ultrasound scan predicts the outcome of continence surgery. Neurourol. Urodynam. 28:90–94, 2009. © 2008 Wiley-Liss, Inc.
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Three‐dimensional ultrasound of the Urethral Sphincter predicts continence surgery outcome
Neurourology and urodynamics, 2009Co-Authors: G. Alessandro Digesu, Dudley Robinson, Linda Cardozo, Vik KhullarAbstract:Aim To assess the predictive value of three-dimensional (3D) ultrasound volumes of the Urethral Sphincter in women undergoing continence surgery. Materials and Methods Women with urodynamic stress incontinence undergoing to Burch colposuspension were prospectively studied using videocystourethrography (VCU), Urethral pressure profilometry (UPP) and a 3D transvaginal ultrasound scan of the urethra. The total Urethral Sphincter volume, Urethral volume, maximum cross sectional area, and rhabdoSphincter volume were calculated, preoperatively. Surgical outcome was assessed at 6 months using VCU. Urethral function parameters were correlated to surgical outcomes using the Mann–Whitney U-test. Results Ninety-one women were studied. Women who failed continence surgery had significantly smaller preoperative Urethral Sphincter volumes than those who had an objective cure (P
C J Fowler - One of the best experts on this subject based on the ideXlab platform.
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Fowler's syndrome: a primary disorder of Urethral Sphincter relaxation
2018Co-Authors: Jn Panicker, Pakzad M, C J FowlerAbstract:Key content: Urinary retention is a relatively uncommon presentation in young women. Women with Fowler's syndrome are often found to have an abnormally elevated Urethral pressure profile, increased Urethral Sphincter volume and characteristically abnormal electromyography of the Urethral Sphincter. The only treatment that has been found to restore voiding in women with Fowler's syndrome is sacral neuromodulation. Sphincter injections of botulinum toxin are a possible outpatient‐based alternative. / Learning objectives: To review the typical symptoms and signs associated with Fowler's syndrome. To share the current understanding about why this condition may occur. To understand how to evaluate and treat a woman with suspected Fowler's syndrome. / Ethical issues: Fowler's syndrome should be considered in women presenting with urinary retention where the cause for retention is uncertain
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Urethral Sphincter volumes in women with obstructed voiding and abnormal Sphincter electromyographic activity.
BJUI, 1995Co-Authors: J.g. Noble, P.j. Dixon, D. Rickards, C J FowlerAbstract:Objective To investigate the role of transrectal ultrasonography (TRUS) of the female Urethral Sphincter and to compare Sphincter volumes in controls and women with obstructed voiding associated with abnormal myotonic-like electromyographic (EMG) activity in the Urethral Sphincter. Patients and methods Fourteen women patients (mean age 29 ± 3.2 years) with symptoms of urinary outlet obstruction underwent videocystometrography (VCMG), Urethral Sphincter EMG and TRUS. Their Sphincter volumes were compared with those obtained from 20 age-matched control patients with other urodynamic diagnoses or normal urodynamics. Results In every patient the Urethral Sphincter was identified as an ovoid, hypoechoic structure distal to the bladder outlet. The mean volume of the Sphincter in those patients with abnormal EMG activity (3.05 ± 0.23 cm3) was significantly greater than that in the control group (1.30 ± 0.09 cm3; P < 0.001). Conclusion TRUS provided a useful method of imaging the Urethral Sphincter in women. The results suggest that there was an increase in the volume of the Urethral Sphincter in females with obstructed voiding, providing collateral evidence that the abnormal EMG activity is a significant factor in the pathophysiology of the disorder.
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Urethral Sphincter electromyography
International Urogynecology Journal, 1993Co-Authors: I. Eardley, C J FowlerAbstract:Electromyography of the pelvic floor muscles may be used to assess their innervation using the technique of motor unit analysis. Prolongation of motor unit duration and an increase in motor unit amplitude reflects denervation and reinnervation of these muscles. This principle may be used to detect and investigate nerve damage in a variety of disorders which affect the musculature of the pelvic floor, including multiple system atrophy. It has also been used to investigate the effects of childbirth on the pelvic floor and to investigate the relationship between damage to the innervation of the pelvic floor and stress incontinence. Finally, Urethral Sphincter electromyography has detected abnormal electrical activity in some women with obstructed voiding, which may reflect abnormal relaxation of the striated Urethral Sphincter.
Michael B. Chancellor - One of the best experts on this subject based on the ideXlab platform.
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Botulinum toxin Urethral Sphincter injection resolves urinary retention after pubovaginal sling operation.
International urogynecology journal and pelvic floor dysfunction, 2002Co-Authors: Christopher P. Smith, Margie O'leary, Janet Erickson, George T. Somogyi, Michael B. ChancellorAbstract:The management of prolonged urinary retention following pubovaginal sling surgery typically involves transvaginal urethrolysis for anatomical Urethral obstruction. Brubaker [1] recently reported on Urethral Sphincter abnormalities as a cause of postoperative urinary retention following either Burch suspension or pubovaginal sling procedure. We report a case of functional Urethral obstruction and detrusor acontractility following pubovaginal sling surgery that was successfully treated by botulinum A toxin Urethral Sphincter injection.
Jonathan S Carp - One of the best experts on this subject based on the ideXlab platform.
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long term recording of external Urethral Sphincter emg activity in unanesthetized unrestrained rats
American Journal of Physiology-renal Physiology, 2014Co-Authors: Brandon K Lapallo, Jonathan R Wolpaw, Xiang Yang Chen, Jonathan S CarpAbstract:The external Urethral Sphincter muscle (EUS) plays an important role in urinary function and often contributes to urinary dysfunction. EUS study would benefit from methodology for longitudinal reco...
