Abnormal urethral motor function is common in female stress, mixed, and urge incontinence

Urine flow acceleration in healthy children: A retrospective cohort study

AIMS

To establish normal reference values of urine flow acceleration (Q_acc ) in healthy children, as there is a lack of nomograms for normative reference values of Q_acc by voided volumes in the pediatric population so far. Q_acc might be an early indicator of autonomic neuropathy in children and adolescents.

METHODS

Data were retrospectively collected from healthy children who underwent uroflowmetry between 1990 and 1992. Exclusion criteria were voided volume less than 20 ml, and postvoid residual more than 15%. Baseline characteristics and uroflowmetry parameters were collected from girls and boys aged between 6 and 18 years. Voided volume, voiding time, time to maximum flow rate, and maximum and average flow rates of urine were measured, and Q_acc was calculated. Postvoid bladder diameter was measured by ultrasonography and converted to volume.

RESULTS

Uroflowmetry parameters of 208 children (≤18 years old, 45.2% girls, mean age 9.68 ± 3.09 years) who performed 404 micturition were analyzed. Median voided volume, voiding time, time to Q_max , Q_ave , Q_max , Q_acc , and postvoid residual volume were 130 [20-460] ml, 10 [3-56] s, 3 [1-14] s, 11.7 [2.5-36.6] ml/s, 20.5 [5-50] ml/s, 6 [0.81-25] ml/s² , and 1.83 [0-38.62] ml, respectively. Q_acc nomograms were given in centile forms for girls and boys separately, which show an inversely proportional correlation between voided volumes.

CONCLUSIONS

These are the first nomograms for normative reference values of Q_acc in the pediatric population (girls and boys separately) by voided volumes in centile forms. These may be useful to interpret abnormal Q_acc values and diagnose lower urinary tract diseases over a wide range of voided volumes.

Neuromuscular urethral function and urethral urodynamic parameters between urgency and stress incontinence do not differ

INTRODUCTION AND HYPOTHESIS

To describe and compare urethral neuromuscular function using concentric needle electromyography (CNEMG) and urodynamic (UDS) parameters between stress incontinent (SUI) and urge incontinent (UUI) women.

METHODS

Incontinent women were recruited from a urogynecology clinic if they answered "sometimes" or "always" to one of the items on the Medical, Epidemiologic, and Social Aspects of Aging questionnaire. Participants were categorized by MESA scores into stress (SUI) or urgency (UUI) incontinence groups. Participants underwent CNEMG of the striated urethral sphincter at three insertion sites using Medtronic multiple motor unit action potential analysis. UDS was performed with Laborie microtip catheters: urethral pressure profiles were obtained at baseline and 300 ml. Data were analyzed in SPSS. Continuous variables were compared with independent t-test or Mann-Whitney U, categorical variables with chi-square test. A logistic regression was performed to control for variables found to be significant on univariate analysis.

RESULTS

Fifty-six women (37 SUI, 19 UUI) with mean ± SD age of 53 ± 13 years participated. At baseline, patients with SUI were younger, more likely to be premenopausal and had lower BMIs. There were no differences in urethral EMG or UDS parameters between UUI and SUI women except lower maximum cystometric capacity in women with UUI. When controlling for age, BMI and MCC on logistic regression, there remained no differences between SUI and UUI groups on EMG or UDS parameters.

CONCLUSIONS

Women with UUI and DO show similar evidence of denervation-reinnervation injury to the striated urethral sphincter muscle as women with SUI.

The pathophysiology of stress urinary incontinence: a systematic review and meta-analysis

Introduction and hypothesis

To evaluate the evidence for pathologies underlying stress urinary incontinence (SUI) in women.

Methods

For the data sources, a structured search of the peer-reviewed literature (English language; 1960–April 2020) was conducted using predefined key terms in PubMed and Embase. Google Scholar was also searched. Peer-reviewed manuscripts that reported on anatomical, physiological or functional differences between females with signs and/or symptoms consistent with SUI and a concurrently recruited control group of continent females without any substantive urogynecological symptoms. Of 4629 publications screened, 84 met the inclusion criteria and were retained, among which 24 were included in meta-analyses.

Results

Selection bias was moderate to high; < 25% of studies controlled for major confounding variables for SUI (e.g., age, BMI and parity). There was a lack of standardization of methods among studies, and several measurement issues were identified. Results were synthesized qualitatively, and, where possible, random-effects meta-analyses were conducted. Deficits in urethral and bladder neck structure and support, neuromuscular and mechanical function of the striated urethral sphincter (SUS) and levator ani muscles all appear to be associated with SUI. Meta-analyses showed that observed bladder neck dilation and lower functional urethral length, bladder neck support and maximum urethral closure pressures are strong characteristic signs of SUI.

Conclusion

The pathology of SUI is multifactorial, with strong evidence pointing to bladder neck and urethral incompetence. While there is also evidence of impaired urethral support and levator ani function, standardized approaches to measurement are needed to generate higher levels of evidence.

Urethral Pressure Variation: A neglected contributing factor in patients with overactive bladder syndrome?

OBJECTIVE

To study urethral pressure variations during the whole filling phase among different groups of patients.

MATERIAL AND METHODS

We investigated 79 consecutive patients from January 2011 to June 2012. All patients were recruited within our routine practice in our continence clinic and were evaluated with urodynamic exam according to the standards of the International Continence Society (ICS) with an additional continuous measurement of the urethral pressure profile (cUPP) that was done in a supine position. Patients with genital prolapse >grade I, as well as patients with impaired cognitive function or neurogenic disorders were excluded. Bacteriuria at the time of investigation was excluded by urine analysis. Urethral pressure changes higher than 15cmH2O were considered as 'urethral instability'.

RESULTS

From 79 investigated patients, 29 were clinically diagnosed with OAB syndrome, 19 with stress urinary incontinence (SUI) and 31 with mixed (OAB and SUI) incontinence. The prevalence of 'urethral instability' as defined in this study was 54.4% (43/79). The mean Δp in patients with OAB (36.5cmH2O) was significantly higher (p<0.05) than in groups with pure stress (14.9cmH2O) and mixed urinary incontinence (19.3cmH2O).

CONCLUSIONS

Etiology of 'urethral instability' is unknown, but high prevalence among patients with overactive bladder syndrome, especially concomitant with detrusor activity can raise a fair question and direct further diagnostic as well as treatment efforts.

Sacral neuromodulation effects on periurethral sensation and urethral sphincter activity

AIMS

To characterize the effect of sacral neuromodulation (SNM) on urethral neuromuscular function.

METHODS

Following IRB approval, women with refractory overactive bladder (OAB) underwent standardized urethral testing prior to and after Stage 1 SNM implantation. Periurethral sensation was measured using current perception thresholds (CPT). Striated urethral sphincter activity was quantified using concentric needle electromyography (CNE) and Multi-Motor Unit Action Potential (MUP) analysis software. Nonparametric analyses were used to characterize pre/post changes with intervention. Baseline CPT and CNE findings were compared between SNM responders and non-responders.

RESULTS

Twenty-seven women were enrolled in this pilot study with a mean age of 61 ± 13 years. Twenty of 26 women (76.9%) responded to SNM and went to Stage 2 permanent implantation. Four (14.8%) withdrew after Stage 1 implantation; three of the four withdrawals had not had therapeutic responses to SNM. CPT and CNE parameters did not significantly differ from baseline 2 weeks after SNM. Pre-SNM urethral sensation was not significantly different between responders and non-responders. However, responders had larger amplitude, longer duration and more turns and phases at baseline approaching significance, reflecting more successful urethral reinnervation, than non-responders.

CONCLUSIONS

SNM does not alter urethral neuromuscular function 2 weeks post Stage 1 implantation.