Urethral retro-resistance pressure: A new clinical measure of urethral function

Do we need better methods of assessing urethral function: ICI-RS 2013?

AIMS

To assess whether current methods of urethral function assessment are sufficient for clinical requirement.

METHODS

A summary of the debate held at the 2013 meeting of the International Consultation on Incontinence Research Society, with subsequent analysis by the authors.

RESULTS

All reported methods of assessment were reviewed and a summary of reported efficacy and clinical application for each is given. Every method of assessment has limitations as to its use, and in some cases the methods have yet to be proved reliable.

CONCLUSIONS

A gap exists between clinical requirements and the capacity of current urethral function assessments to assist diagnosis. Recommendations are therefore made for future research topics.

The evidence for urodynamic investigation of patients with symptoms of urinary incontinence

Urodynamic studies are the gold standard to objectively diagnose dysfunction of the lower urinary tract. The widely available evidence for the clinical relevance is, however, fragmented. This article summarizes the published knowledge supporting the use of urodynamic studies in urinary incontinence in female, male and frail patients, as well as patients with relevant neurological disease. Five technological innovations are discussed briefly. Standard urodynamic cystometry can, on the basis of a solid body of evidence, objectively unveil the entire function of the lower urinary tract in all patients with urinary incontinence, regardless of the patients' perception of (ab-)normality of signs and or symptoms.

Executive summary: The International Consultation on Incontinence 2008--Committee on: "Dynamic Testing"; for urinary incontinence and for fecal incontinence. Part 1: Innovations in urodynamic techniques and urodynamic testing for signs and symptoms of urinary incontinence in female patients

AIMS

The members of The International Consultation on Incontinence 2008 (Paris) Committee on Dynamic Testing' provide an executive summary of the chapter 'Dynamic Testing' that discusses (urodynamic) testing methods for patients with signs and or symptoms of urinary incontinence. Testing of patients with signs and or symptoms of faecal incontinence is also discussed.

METHODS

Evidence based and consensus committee report.

RESULTS

The chapter 'Dynamic Testing' is a continuation of previous Consultation-reports added with a new systematic literature search and expert discussion. Conclusions, based on the published evidence and recommendations, based on the integration of evidence with expert experience and discussion are provided separately, for transparency.

CONCLUSION

This first part of a series of three articles summarizes the committees recommendations about the innovations in urodynamic study techniques 'in general', about the test characteristics and normal values of urodynamic studies as well as the assessment of female with signs and or symptoms of incontinence and includes only the most recent and relevant literature references.

Preoperative urethral parameters at rest and objective cure following laparoscopic colposuspension

INTRODUCTION AND HYPOTHESIS

The aim of this study is to investigate associations between preoperative resting urethral parameters and objective outcome of laparoscopic colposuspension.

METHODS

Data from 219 stress incontinent women who underwent laparoscopic colposuspension, with leakage at standardized pad test repeated after surgery, were collected. Associations between objective cure and preoperative maximum urethral closure pressure, functional urethral length, and continence area were analyzed using receiving operator characteristics curves. The level for 75% cure for each parameter was identified.

RESULTS

All parameters were positively associated with cure. Continence area showed the strongest association. No cut-off values for prediction of failure were found. Women having levels equal or higher than the "75% cure level" for all urethral parameters had a cure rate of 88% compared with 55% for women with all parameters lower than this level.

CONCLUSIONS

A combination of the urethral parameters may be useful for identifying patients with excellent chance for cure after colposuspension. Further studies are needed on continence area.

Urethral retro-resistance pressure: association with established measures of incontinence severity and change after midurethral tape insertion

AIMS

Our study explored the relationship between URP and established measures of incontinence severity. We also report on change in URP after insertion of midurethral tape (MUT).

METHODS

All participants had incontinence secondary to urodynamic stress incontinence only. URP was measured using the Monitorr (Gynecare) device prior to and 3 months after MUT insertion. The following measures of incontinence severity were completed before and 3 months after insertion of MUT: 24-hour pad test; International Consultation on Incontinence Questionnaire for evaluating symptoms and impact of urinary incontinence; King's Health Questionnaire for evaluating disease-specific quality of life and a 3-day urinary dairy with episodes of incontinence recorded.

RESULTS

Preoperative URP and measures of incontinence severity were available for 100 women. Mean URP bore no relationship to the severity of urine loss assessed by 24-hour pad loss. There was no correlation between URP and other measures of incontinence severity. Pre and postoperative URP was available in 73 women. Although 84.9% were objectively cure (24-hour pad test of <5 g) after surgery, pre and postoperative URP was not significantly different [62.7 (+/-19.4) cmH(2)O vs. 61.2 (+/-204) cmH(2)O; p = 0.57].

CONCLUSIONS

Urethral retro-resistance pressure is not a useful measure of urethral function.

Urodynamics in the management of female stress incontinence--which test and when?

PURPOSE OF REVIEW

This article reviews the literature from the last 12 months in the context of our existing knowledge base and reviews the contentious issue of the role of preoperative urodynamics for stress urinary incontinence, with particular reference to the choice of urodynamic investigations for diagnostic differentiation between intrinsic sphincter deficiency and urethral hypermobility, assessing symptom severity and predicting postoperative prognosis.

RECENT FINDINGS

While there are significant conflicting data regarding the role of urodynamics, particularly in the functional assessment of the urethra, it is clear that these diagnostic techniques can provide clinically useful data. It is in this context that recent guidelines advising on restricted use of invasive urodynamics preoperatively should be carefully reviewed.

SUMMARY

There is a pressing need for randomized controlled trials to be performed to fully assess the role of urodynamics in the preoperative assessment of stress urinary incontinence, especially at this time of rapid change in the surgical treatments available.

[Urodynamic study in the female urinary incontinence evaluation, with the new MoniTorr MR system (non-multichannel urodynamic with urethral retro-resistance pressure measure). Experience with 100 patients]

OBJECTIVE

To compare the clinical diagnosis of the urinary incontinence with the results of LPP and URP obtained by non-multichannel urodynamic. To evaluate the tolerance of the patients to this examination.

PATIENT AND METHOD

Between August and December 2006, 100 urodynamics were made in patients with clinical diagnosis of urinary incontinence, in the Urogynecology Unit of Clinica Las Condes. The clinical diagnosis was compared with the urodynamic results. A subjective tolerance scale was applied (0 was greater tolerance and 10 was maximum discomfort).

RESULTS

In 66 patients with clinical diagnosis of IUS, the urodynamic registered 10 Type 0, 2 (I), 23 (II), 1 (III), 17 (II+III), 1 hyperactive detrusor, 5 (0+ hyperactive detrusor). 3 (II+hyperactive detrusor) and 4 (II+III+hyperactive detrusor). In 15 with Mixed urinary incontinence, the urodynamic showed 6 (Type 0), 2 (II), 2 (II+III), 3 hyperactive detrusor, 1 (II+hyperactive detrusor) and 1 (III+hyperactive detrusor). In 16 patients with urgency incontinence, urodynamic showed 2 normal, 4 (II+III), 7 hyperactive detrusor, 1 (II+hyperactive detrusor) and 2 (II+III+hyperactive detrusor). In 3 patients (two vaginal cuff prolapse and one cistocele, degree IV POP-Q) the urodynamic was indicated in the pre-surgery study considering a great potentially incontinence after correction. Respectively, the patients presented: IUS type III+hyperactive detrusor, IUS type II+III and one normal. All patients expressed 2 and 3 degree tolerance (subjective scale: 1 major tolerance and 10 a minor tolerance).

CONCLUSIONS

The MoniTorr MR urodynamic is a complementary examination very useful in the study of the urinary incontinence. It allows planning the solution adapted for each case and has a high degree of tolerance in the patients.

The correlation of urethral resistance pressure with maximum urethral closure pressure and stress incontinence

OBJECTIVE

Aim of the study was to correlate urethral retro resistance pressure with the maximum urethral closure pressure (MUCP) and functional urethral length (FUL) in patients with urinary incontinence and healthy individuals.

STUDY DESIGN

Two hundred and twenty patients with the complaint of urinary incontinence had a urodynamic examination including urethral pressure profiles and URP. Additionally, 15 healthy individuals without the complaint of any incontinence had their URP and urethral pressure profiles measured. The correlation of MUCP, FUL and URP were calculated using Graph Pad Instat 4.0 for windows.

RESULTS

URP correlates well with the diagnosis of urodynamic stress incontinence. Correlation coefficient between URP and MUCP is 0.9262. Healthy individuals have significantly higher values for URP and MUCP.

CONCLUSION

URP is a valuable less invasive test than conventional urethral function tests for the diagnosis of urodynamic incontinence with an excellent correlation of MUCP and URP.

The effect of spinal anaesthesia on urethral function

This study was to assess the effect of spinal anaesthesia on urethral retro-resistance pressure (URP), cough pressures and tendency to leak. The population consisted of 32 women undergoing a tension-free vaginal tape (TVT) operation under a spinal anaesthetic. URP, cough pressures and an assessment of the degree of leak were performed before the spinal anaesthetic was placed. A standard anaesthetic technique was used, and measurements were repeated after the spinal anaesthetic was inserted. The degree of leak was assessed on a five-point scale with 350 ml in the bladder. The cough pressures and URP values were averaged over three or more measurements. The mean URP value fell from 75.0 to 54.0 cm/H2O (p = 0.0003) after the spinal was inserted. There was a non-significant fall in mean cough pressure from 85.0 to 67.5 cm/H2O (p = 0.06). The degree of leakage increased (p = 0.005). Spinal anaesthesia causes a fall in the resistance in the urethra but does not cause a significant fall in the pressure generated by a cough. Women are more likely to leak after coughing during the TVT operation under spinal anaesthesia than they are before the spinal is inserted. The cough test under spinal anaesthesia does not mimic the result of coughing without a spinal.

Opening vesical pressure: a new test to discriminate urethral sphincter deficiency?

Urethral sphincter deficiency (USD) is not standardised. Opening vesical pressure could reflect the pressure exerted to overcome urethral resistance during void; thus, we evaluated if it could discriminate USD. Women with urinary symptoms were prospectively assessed with a questionnaire and urodynamics and divided into three groups: urodynamic stress incontinence with USD (group 1), urodynamic stress incontinence related to urethral hypermobility without USD (group 2) and normal urodynamic (group 3). USD was defined as the concomitant presence of severe urodynamic stress incontinence, VLPP <60 cm H2O, MUCP <20 cm H2O and urethral mobility <30 degrees . A total of 145 women were enrolled: 56 in group 1, 50 in group 2 and 39 in group 3. The three groups did not differ for demographics, obstetric and surgical history. The median values for opening vesical pressures were 17.5 (15.6-22.2 95%CI), 30 (27.0-37.3 95%CI) and 30 (30.6-44.2 95% CI) for the groups 1, 2 and 3, respectively. A p value <0.0001 was found when comparing group 1 either with group 2 or 3. Opening vesical pressure is a promising parameter to detect USD.

The effects of duloxetine on urethral function and sphincter morphology

The aim of our study was to investigate the effect of duloxetine on urethral function and sphincter ultrasound morphology in 54 women, who were referred to a urogynecology unit, with urodynamic stress incontinence. All completed a King's Health Questionnaire and a patient global assessment of improvement (PGI-I) question and underwent urethral pressure profilometry, measurement of urethral retro-resistance pressure (URP), and ultrasound of the striated urethral sphincter. The investigations were repeated after 8 weeks of duloxetine 40 mg twice daily in 36 women who continued the medication. After 8 weeks of duloxetine, the mean URP increased significantly compared to baseline (53.8 to 60.8 cm H2O; p=0.001), and sphincter thickness was significantly higher (1.8 to 2.0 mm; p<0.001). There was a significant increase in the maximum urethral closure pressure (MUCP) (52.7 to 59.2 cm H2O; p=0.006) but not of functional urethral length. Subanalysis of responders (improved on duloxetine) showed a significant increase in URP (50.3 to 59.1 cm H2O; p=0.001), sphincter thickness (1.7 to 2.1 mm; p<0.001), and MUCP (50.2 to 58.1 cm H2O; p=0.03). These changes were not seen in nonresponders. This study has demonstrated objective changes in urethral ultrasound morphology and function after duloxetine therapy, which relate to improved continence. A larger longer term study is required to assess if these changes persist over time. In summary, duloxetine therapy for urodynamic stress incontinence results in an increase in urethral closure pressure, URP measurement, and urethral striated sphincter thickness.

Urodynamic assessment of sphincteric function in the incontinent female: which test, and does it matter anyway?

The overall prevalence of urinary incontinence among women surveyed in the United States is approximately 37%. The lifetime risk of undergoing urinary incontinence surgery for women in the United States is estimated to be 11.1%. Conservative therapy can be instituted without performing extensive evaluation such as urodynamics, voiding cystourethrograms, ultrasonography, or video studies. Further evaluation is recommended when conservative measures have failed or if invasive, potentially morbid surgical therapies are being considered. This paper reviews the available methods for evaluating the urinary sphincter in the incontinent female.

The relationship of urethral resistance pressure and pressure flow parameters in women with lower urinary tract symptoms

This prospective study aims to evaluate the relationship between urethral resistance pressure (URP) and pressure flow parameters in women with lower urinary tract symptoms (LUTS). Consecutive women with LUTS attending three tertiary referral urodynamic clinics were asked to undergo urodynamic evaluation, pressure flow studies and URP measurement. The pressure flow parameters such as detrusor pressures at the start of flow (ODP), detrusor pressure at peak flow rate (PdetQmax), peak flow rate (Qmax) and detrusor pressure at the end of flow (CDP) were measured. The relationship between URP and pressure flow parameters was evaluated as well as differences between each urodynamic group. Two hundred seventy-nine women attended for urodynamic investigations. Two hundred twenty-three (79.9%) women had good quality pressure flow measurements and were included in the study. The mean age was 58 years (range 21-83). Women with urodynamic stress incontinence had significantly lower URP and ODP than those with detrusor over-activity [54.8 (+/-17.9) and 12.4 (+/-4.1) cmH(2)O, respectively, vs 85.6 (+/-21.4) and 33.7 (+/-13.3) cmH(2)O, respectively) (p<0.05, Bonferroni test). Furthermore, women with urodynamic stress incontinence have significantly lower PdetQmax values as well as higher Qmax than women with competent urethral sphincters (p<0.05, Bonferroni test). There was a significant correlation between ODP, PdetQmax, Qmax and URP measurements. In urodynamic stress incontinence, both URP and pressure flow parameters are reduced. Although the trend for values of both tests were similar and there was a significant correlation between these tests, we should consider that urethral function at rest differ from that during voiding due to activation of additional mechanisms. Therefore, further study is needed to confirm our results.

Urogynaecology: Urethral retro-resistance pressure and urodynamic diagnoses in women with lower urinary tract symptoms

OBJECTIVE

This study determines whether the retrograde urethral retro-resistance pressure (URP) measurement discriminates between urodynamic diagnoses in a group of women.

DESIGN

A prospective observational study.

SETTING

Urogynaecology units of three tertiary referral teaching hospitals.

POPULATION

Women with lower urinary tract symptoms.

METHODS

Consecutive women attending the urodynamic clinics of three tertiary referral teaching hospitals were studied using a validated urinary symptom questionnaire, URP measurement and urodynamic evaluation between February and July 2004. The URP mean values were compared with urinary symptoms and urodynamic diagnoses, using the independent t test correction for multiple measurements.

MAIN OUTCOME MEASURES

Retrograde URP, urodynamic diagnoses and urinary symptoms.

RESULTS

One hundred and eighty-five women were recruited. Women with urodynamic stress incontinence (USI) have significantly lower URP than women with competent urethral sphincters (P < 0.05, independent t test). Women with mixed urodynamic incontinence had values of URP intermediate between women with detrusor overactivity (DOA) and those with USI. In the mixed group, URP mean values were not significantly different from those with DOA and competent sphincters or USI (P > 0.05, independent t test). There was no significant difference between mean URP values and different urinary symptoms (P > 0.05, independent t test).

CONCLUSIONS

There are significantly different URP measurements between women with DOA and those with USI. However, the URP is not a diagnostic tool.

Changes in urethral resistance in the presence of detrusor activity

This was a prospective study performed at two tertiary referral teaching hospitals. The aim of our study was to investigate changes in urethral resistance with the bladder full compared to empty in women with different urodynamic diagnoses. Consecutive women attending the urodynamic clinics were asked to undergo urethral retro-resistance pressure (URP) measurement with the bladder empty and then full. 106 women were recruited - 25 had normal urodynamic studies, 17 had detrusor overactivity, 57 had urodynamic stress incontinence and 7 had mixed incontinence. Women with urodynamic stress incontinence have lower URP values than women with normal urodynamic studies or those with detrusor overactivity with the bladder empty (p = 0.01). Women with normal urodynamic studies and urodynamic stress incontinence showed a statistically significant rise in URP with the bladder full (p = 0.013 and p = 0.003, respectively). In women with detrusor overactivity, the converse was seen - URP was significantly lower with the bladder full compared to empty (p = 0.004). Our study has shown that bladder filling alters URP measurement and bladder volume should be standardised for reporting URP.

An evidence-based approach to the evaluation and management of stress incontinence in women

PURPOSE OF REVIEW

The aim of this article is to use evidence-based criteria to review recent publications on the evaluation and management of stress urinary incontinence in women.

RECENT FINDINGS

Longitudinal studies suggest that a familial predisposition towards stress urinary incontinence may exist. There is mounting evidence that cesarean section may play a protective role against pelvic floor damage due to labor, but this continues to be investigated. Objective parameters in the evaluation of stress urinary incontinence, such as questionnaires, pad test, and urodynamic studies, continue to undergo refinements to become more clinically relevant outcome tools. Non-invasive and minimally-invasive therapies for stress urinary incontinence are expanding. The search continues for the optimal non-autologous material in the pubovaginal sling procedure. Despite concerns over the use of synthetic material and better defined early complications, midurethral slings continue to enjoy popularity with short-term and intermediate success.

SUMMARY

Further research into the cause of stress urinary incontinence is necessary. There is still no unified protocol in the evaluation of the condition and its severity. Mid-urethral slings appear to be as efficacious as more established procedures (bladder neck suspensions, pubovaginal slings), but long-term results on safety and efficacy remain scarce.