Definiendo disfunción vesical en mujeres - Neurol Urodyn 12

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Neurourology and Urodynamics 31:313–316 (2012)

Defining Female Voiding Dysfunction: ICI-RS 2011 Dudley Robinson,1* David Staskin,2 Rosa M. Laterza,3 and Heinz Koelbl3 1

Department of Urogynaecology, Kings College Hospital, London, UK Department of Urology, Tufts University School of Medicine, Boston, Massachusetts 3 Department of Obstetrics and Gynaecology, Johannes-Gutenberg University, Mainz, Germany 2

Whilst symptoms of Bladder Outlet Obstruction (BOO) and post micturition symptoms are more commonly reported in men a significant number of women may also complain of voiding dysfunction. However, despite the recent advances in the standardisation of terminology of lower urinary tract dysfunction there remains a lack of consensus regarding a precise diagnosis and definition of voiding abnormalities in women. In addition voiding symptoms may co-exist with storage symptoms as well as those associated with urinary incontinence. Consequently many patients present with a spectrum of different urinary symptoms, related to both storage and voiding, which may be multifactorial in origin or be related to one another. The purpose of this paper is to review the current literature in order to accurately define and classify female voiding dysfunction including causes and aetiology. In addition to reviewing the investigation and management of those women with voiding dysfunction recommendations are proposed for management in clinical practice as well as suggestions for future researc Neurourol. Urodynam. 31:313–316, 2012. ß 2012 Wiley Periodicals, Inc. Key words: female; OAB; urinary incontinence; voiding dysfunction

INTRODUCTION

Lower urinary tract dysfunction and urinary incontinence are common conditions and the associated symptoms are known to have a significant effect on quality of life.1 Whilst voiding and post-micturition symptoms are more common in men a significant number of women also complain of voiding dysfunction (VD) although at present there is a lack of consensus regarding diagnosis and definition. In addition, symptoms associated with bladder emptying may co exist with storage symptoms, such as urgency, frequency, and nocturia as well as symptoms associated with urinary incontinence. Consequently, individual patients may have a number of different, but related, conditions affecting the lower urinary tract, in addition to VD, such as difficulty in initiating micturition and bladder emptying. The purpose of this paper is to review the current literature in order to accurately define female bladder dysfunction and also to make recommendations relative to both clinical practice and research. PREVALENCE

Female VD is defined by the International Continence Society and International Urogynaecological Association as ‘‘abnormally slow and/or incomplete micturition based on symptoms and urodynamic investigations.’’2 Prevalence of Voiding Dysfunction—Symptoms

Using a symptom-based definition, epidemiological studies have revealed that voiding symptoms are more common in men than women. The EPIC study was a population-based cross-sectional study of 19,165 men and women in Canada, Germany, Italy, Sweden, and the UK.3 Overall 62.5% of men and 66.6% of women complained of lower urinary tract symptoms (LUTS). Whilst women complained of more storage symptoms than men (59.2% and 51.3%, respectively) men were more likely to complain of VD (25.7% compared to 19.5%). Interestingly 8% of women complained of both storage and voiding symptoms whilst 7% complained of storage,

ß 2012 Wiley Periodicals, Inc.

voiding, and post-micturition symptoms. These findings are supported by a further large cross-sectional internet survey of 30,000 patients in the USA, UK, and Sweden. Overall 5.2% of women over the age of 40 years had voiding symptoms and 14.9% complained of both voiding and storage symptoms. In addition both men and women who complained of VD were also more likely to experience storage and post-micturition symptoms with 26.3% of women being affected.4 The evidence from both of these studies would suggest that whilst voiding symptoms would appear to be less common in women they are often found in association with other storage-related symptoms and rarely exist in isolation. Prevalence of Voiding Dysfunction—Urodynamic Investigations

Whilst there is some consensus regarding the definition of voiding symptoms there is no such consensus regarding urodynamic investigation and the prevalence varies depending on the definition of post-void residual used. In addition many women may be found to have an asymptomatic residual. In a study of 96 pre- and post-menopausal women the median post-void residual was 19 mls (range: 0–145 mls) with 85% of the sample having a residual 100 mls was 10%.6 These findings are Christopher Chapple led the review process. Conflict on interest: Consultancy Work—Astellas, Pfizer, Ferring, Gynaecare; Allergan Lecturing—Astellas, Pfizer; Gynaecare Reasearcher—Astellas, Pfizer. *Correspondence to: Dudley Robinson, Consultant, Urogynaecology Department, King’s College Hospital, London, UK. E-mail: [email protected] Received 3 January 2012; Accepted 12 January 2012 Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/nau.22213

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TABLE I. Causes of Female Voiding Dysfunction

TABLE II. Voiding and Post-Micturition Symptoms

Detrusor hypotonia Detrusor underactivity Pharmacological Ageing Overdistension injury Chronic urinary retention Acontractile detrusor Neurogenic Spinal cord injury Bladder outflow obstruction Physiological Urogenital prolapse Urethral stricture Neurogenic—Fowler’s syndrome Iatrogenic Urethral trauma Continence surgery Prolapse surgery

Hesitancy Slow stream Intermittency Straining to void Spraying (splitting) Incomplete bladder emptying Need to immediately re-void Post-micturition leakage Position-dependent micturition Dysuria

supported by a larger retrospective case–control study of 1,399 women complaining of pelvic floor dysfunction where the incidence of post-void residual >100 mls was 11%.7 Furthermore, a large prospective study of post-void residual urine volumes in women complaining of pelvic floor dysfunction, measured using transvaginal ultrasound, reported 19% of women with a residual of >30 mls and 5% >100 mls.8 These data would appear to support the use of 100 mls in clinical practice as being significant. ETIOLOGY

The causes of female VD can be broadly divided into detrusor underactivity and outflow obstruction which may either be physiological or iatrogenic (Table I). When considering the pathophysiological changes associated with female VD there is some evidence to show that this may lead to partial autonomic denervation within the detrusor muscle and this may lead to further functional impairment of contractility.9 Evidence would also suggest that outflow obstruction may alter the contraction properties of detrusor muscle by causing changes in the cell-to-cell propagation of electrical activity and changes in membrane potential leading to an increase in cell irritability.10 Further work in the rat model has shown urethral obstruction may lead to a degree of neural plasticity resulting in a more prominent spinal reflex11 as well as an increase in nerve growth factor which may alter the size and function of neurons within the detrusor muscle.12 These findings would suggest that there is an increased risk of developing detrusor overactivity following outlet obstruction and support the epidemiological studies linking VD and storage symptoms. RISK FACTORS FOR FEMALE VOIDING DYSFUNCTION

Evidence from prevalence studies has identified several risk factors which may be associated with an increased risk of developing VD. Symptoms associated with an elevated post-void residual in women complaining of pelvic floor disorders, include feeling a bulge in the vagina, pelvic pressure, splitting of urination stream, and the absence of urinary incontinence. Urogenital prolapse has also been shown to be an independent risk factor for post-void residuals >100 mls, although the positive and negative predictive values are low (64% and 59%, respectively).13 Neurourology and Urodynamics DOI 10.1002/nau

Similar studies have also investigated the risk factors associated with VD in patients with OAB. The presence of urogenital prolapse  stage II, symptoms of voiding difficulty, and the absence of stress urinary incontinence have been shown to predict 82% of women with an elevated post-void residual.6 In addition age >55 years, prior incontinence surgery, a history of multiple sclerosis and urogenital prolapse  stage II have also been shown to be independent predictors of increased urinary residuals.14 DIAGNOSIS OF VOIDING DYSFUNCTION

The diagnosis of female VD is dependent on both patient symptoms and the results of lower urinary tract investigation. Symptoms associated with VD (Table II) are commonly associated with post-micturition symptoms and women may also complain of concomitant stress and urgency urinary incontinence. In addition VD and a post-micturition residual may lead to the storage related symptoms of frequency, urgency, and nocturia. The predictive value of voiding symptoms has also been shown to be poor when predicting female VD. In a study of 636 women, symptoms suggestive of VD were found to have a low sensitivity (13–57%) and specificity (18–38%) for elevated post-void residuals.15 This is supported by a further study of 134 women with voiding symptoms that demonstrated poor correlation of both voiding symptoms and post-micturition symptoms with elevated post-void residuals.16 All women complaining of difficulty in micturition should be investigated although the extent of investigation is dependent upon the clinical setting. Those patients who also have storage symptoms or who are suspected of having overactive bladder (OAB) syndrome should be investigated with a free flow rate and post-void residual.17,18 If abnormal, filling cystometry with a pressure flow study will help to determine whether the cause is detrusor underactivity or outlet obstruction. If the latter is suspected then urethral pressure profilometry (UPP) may help in the diagnosis of a urethral stricture. For those women who develop voiding difficulties following continence surgery or where a neurogenic cause of voiding difficulty is suspected, videocystourethrography will provide more information regarding lower urinary tract function and anatomy. Whilst urodynamic studies facilitate the diagnosis of VD in women, currently there is no universally accepted precise diagnostic criteria. Indeed there is some evidence to show that the use of urethral catheters during pressure flow studies may lead to over diagnosis, by increasing outlet resistance.19 Equally the use of bladder outlet obstruction (BOO) nomograms which are used to diagnose outlet obstruction in men has not been found to be useful in women.20 However, there is some evidence to suggest that the use of videocystourethrography may increase diagnostic accuracy. A study of 76 women with

Defining Female Voiding Dysfunction VD has shown that whilst those women with obstruction were found to have significantly higher voiding pressures, lower flow rates, and greater post-void residuals, the absolute values were not as great as those seen in men and simultaneous imaging of the bladder neck/urethra was found to increase diagnostic accuracy, by demonstrating the site of outlet narrowing.21 There is a similar lack of consensus when considering the definition of female VD based on pressure flow parameters. In a retrospective study of 587 women the incidence of BOO was 6.5% based on the criteria of a flow rate 20 cmH2O. Interestingly 63% of these patients complained of mixed voiding and storage symptoms whilst 29% complained of storage symptoms alone.22 Using a flow rate 35 cmH2O the incidence of BOO was found to be 6% in a larger retrospective study of 3,500 women. When considering urinary symptoms, 94% complained of frequency and urgency and 44% of urgency urinary incontinence.23 Both of these studies clearly demonstrate the correlation between storage and voiding symptoms and suggest that often, both are part of a continuum rather than existing in isolation. MANAGEMENT OF FEMALE VOIDING DYSFUNCTION

The management of women with voiding difficulties should be individualized to address the underlying cause and etiology. Many women with small post-void residuals may be entirely asymptomatic and a conservative approach, with double voiding and repeat post-void residual measurements, is all that is required. In women with a symptomatic diagnosis of OAB and VD who are commenced on antimuscarinic therapy it is also important to monitor residual assessments on medication to ensure voiding function is not deteriorating. Those women who develop VD following continence surgery are generally managed with a short-term urethral catheter in the first instance and the evidence would suggest that