Evidence-based management of stress urinary incontinence

Transcription

1 Evidence-based management of stress urinary incontinence Helen C Johnson, Mark Slack /toag A wide range of conservative and surgical managements exists for stress urinary incontinence. The evidence base for these interventions is variable. This is particularly the case for the newer surgical treatments, where surgical innovation has grown ahead of the available research. In this review we link the evidence base with the interventions available. REVIEW Keywords evidence-based, stress urinary incontinence, surgery, pharmacology, lifestyle Introduction Stress urinary incontinence affects millions of women worldwide. Sufferers experience discomfort, restriction of normal activities, social isolation and misery. Despite the impact of the condition, many sufferers fail to present for help because of low awareness or embarrassment. Treatment options for conservative management have been somewhat restricted and doubts have been voiced about efficacy. Consensus now exists that conservative treatment is essential before embarking on surgical treatment.the conservative options have been enhanced by the introduction of pharmacotherapy for the condition. Numerous operations have been described for the surgical management of stress urinary incontinence. Despite the perceived success of this approach, there are still many failures and surgeons have continued to innovate in an attempt to improve outcomes. Innovations aimed at reducing morbidity and time spent in hospital have dominated this field. A range of new procedures for the surgical treatment of stress urinary incontinence has been introduced. These vary according to the route, the materials used and the type of anaesthetic. Some of the procedures have been marketed ahead of the publication of any significant clinical data. Prevalence Estimates of the prevalence of stress urinary incontinence vary widely. Some well-designed, large epidemiological studies have given us an idea of the true prevalence of the condition. One such study surveyed adults aged 40 years or more registered with general practitioners in Leicestershire. 1 Of the women surveyed, 34% reported clinically significant symptoms: 2% of these considered that their symptoms were bothersome or socially disabling. Stress urinary incontinence is most common in those under 50 years of age. However, as the population ages, overactive bladder conditions become far more common. 1 A postal survey carried out in France, Germany, Spain and the UK 2 revealed a regional difference. Only 23% of Spanish respondents reported incontinence episodes in the preceding 30 days compared with the other countries, where the rate was over 40%.The UK and Spain had the lowest consultation rate (25%) compared with Germany (40%). Once again, stress urinary incontinence was most common in those under 55 years of age but this reversed in those over 60 years. Less than 5% had undergone surgery for the condition. Conservative management Lifestyle interventions Weight loss, exercise, cessation of smoking, alteration of fluid management and relief of constipation are frequently cited as methods of reducing incontinence. However, no randomised trials that study the effect of these interventions have been published. Reduction of weight in Author details Helen C Johnson MRCOG, Consultant Obstetrician and Gynaecologist, Hinchingbrooke and Addenbrooke s Hospitals, Cambridge, UK. Mark Slack MMed FCOGSA(SA) MRCOG, Consultant Gynaecologist, Department of Urogynaecology and Reconstructive Pelvic Surgery, Addenbrooke s Hospital, Cambridge University Hospital NHS Foundation Trust, Hills Road, Cambridge, CB2 2QQ, UK. mark.slack@addenbrookes.nhs.uk (corresponding author) Royal College of Obstetricians and Gynaecologists 159

2 REVIEW morbidly obese women with urinary problems has been proven effective. 3 Although weight loss has considerable theoretical benefit, there is little evidence of benefit in the moderately obese. The effects of physical stress from day-to-day activities at home and in the workplace have not been studied. While both smoking and constipation are implicated in the pathogenesis of incontinence, the effect of reversing them has not been studied. 4 Physical therapy Pelvic floor muscle training is the most commonly recommended physical therapy for women with stress urinary incontinence. Adjuncts, such as biofeedback or electrical stimulation, are also commonly used with pelvic floor muscle training. Training regimens vary markedly from area to area.the inconsistency of intervention coupled with different measures of success make these trials difficult to compare. 5 Results show that an improvement can be expected in 40 60% of women. 6 Pelvic floor muscle training seems to be better than no training or placebo. 5 It is difficult to establish the role of other interventions such as biofeedback or electrical stimulation because of limited evidence from small trials. Intensive pelvic floor muscle training is better than standard training programmes for women with stress urinary incontinence. Weighted vaginal cones are better than control treatments for self reported improvement in women with stress urinary incontinence although there is no evidence to support their use in a pelvic floor muscle training programme. 7 Considering that 50% of women cannot perform pelvic floor exercises correctly it is sensible to refer a woman for treatment to a physiotherapist trained in pelvic floor work. 8 This has the advantage of allowing an accurate assessment, providing advice and education and initiating an appropriate pelvic floor programme. Devices to prevent urinary leakage A variety of devices has been proposed for the treatment of stress urinary incontinence. These fit into three categories: bladder neck support devices devices to block the external meatus intraurethral devices. Use of these devices is supported by small studies that show improvement over a short space of time. Bladder neck support resulted in improved continence but required considerable patient acceptance and manual dexterity. Intraurethral devices demonstrated the highest efficacy but were associated with considerable morbidity due to urinary tract infection and haematuria. Patient acceptability was also questionable. 9 Pharmacotherapy Changes to the central nervous system s control mechanisms have been implicated in the pathophysiology of stress urinary incontinence. The suggestion is that the neurotransmitters serotonin and noradrenalin influence the contraction of the urethral sphincter. Abnormalities in their release can act alone or in combination with local damage or degenerative changes to the sphincteric mechanisms. A strong association has been found between clinical depression and idiopathic urinary incontinence. 10 This suggests a common pathology involving serotonin. Theoretically therefore, the enhancement of neurotransmission using serotonin should have a positive beneficial effect on continence. A combined noradrenalin and serotonin reuptake inhibitor, duloxetine, was used in animal studies to demonstrate this effect. In the cat model duloxetine significantly increased sphincteric activity and bladder capacity. 11 Duloxetine has been trialled in a phase II study, three phase III trials and a separate double-blind placebo controlled study The most effective dose was 40 mg twice daily. This dose elicited significant improvements with 50% of the women experiencing a % reduction in episodes of incontinence from baseline diaries. This had a significant effect on their quality of life.the duloxetine-induced improvements were associated with a significant increase in mean time between voids. This shows that the improvements in continence did not result from more frequent emptying of the bladder. The most common adverse event with duloxetine is mild to moderate nausea. A significant number of women experienced dry mouth, fatigue, insomnia, constipation, headaches, dizziness, somnolence and diarrhoea. Discontinuations as a result of these symptoms were only statistically significant from placebo for nausea, fatigue, insomnia, dizziness and somnolence. Adverse effects resulted in discontinuation in more than 10% of women. There was no evidence that women taking the drug had any mood altering effects. While a small number of women discontinued the trial because of nausea, the majority (95%) continued. In those that continued, 52% had resolution of nausea within a week and 81% within a month Royal College of Obstetricians and Gynaecologists

3 Where duloxetine was offered to women on the waiting list for surgery, 20% were no longer interested in undergoing the procedure. 16 Controversy surrounds the use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of moderate to severe depression. Allegations and counter allegations concerning an increase in suicide rates in women taking SSRIs have populated the lay literature. The peer-reviewed literature has given an equal amount of space to the debate. The current opinion is that this class of drugs leads to an increase in suicidal ideation and non-fatal suicide attempts soon after starting treatment. 17 However, there is no increase in fatal suicide attempts and little evidence that this class of drugs has any significant effect on adults. 18 During the trials described there was no evidence that women taking duloxetine experienced suicidal ideation However, considering the controversy surrounding this class of drugs and remembering that duloxetine is a new drug, it is important to use the help of the primary care practitioner when prescribing it and to ensure that any adverse events are recorded using the yellow card system. Physiotherapy should always be offered ahead of surgery. As duloxetine seems to be a complementary therapy, it may become practice to offer both ahead of surgery. Surgery There are many surgical techniques aimed at reducing incontinence for women in whom conservative therapy proves unsuccessful. The desire is to reduce incontinence while improving the quality of life. This is achieved by balancing lasting outcomes with the morbidity associated with the surgery. Only when long-term success has been demonstrated should the focus change to perioperative morbidity and associated parameters. The main techniques to restore continence are: open retropubic colposuspension (Burch, Marshall Marchetti Krantz abdominal paravaginal repair); laparoscopic colposuspension; sling procedures (traditional pubovaginal, midurethral tapes and transobturator tapes); periurethral bulking agents; and artificial urinary sphincters. The use of anterior repair and needle suspension procedures has largely disappeared because of poor long-term outcomes. 19 is predominantly based on case-series rather than randomised controlled trials. Many publications have small numbers or short follow-up periods and the women have a mixture of diagnoses and investigations. The surgical techniques used are also not always clear, so combining small study results in a meta-analysis is difficult. Also confounding the meta-analysis of studies is the fact that many do not provide a clear description of what constitutes cure, either objective or subjective.this can be based upon urodynamics, stress tests or pad tests: a significant difference rather than dryness is the objective cure. Women s satisfaction has been based on simple questioning, visual analogue scales and a range of validated quality-of-life surveys. Hilton 20 discussed at some length the difficulties of extrapolating studies, including the problems with the definition of cure, external validity and statistical power. An example of how cure definition alters the rates can be seen in the trial comparing tension-free vaginal tape (TVT) with colposuspension. 21 Using the Bristol female lower urinary tract symptoms (BFLUTS) validated questionnaire, 25% of women in the TVT group were completely dry following surgery, yet 43% reported a cure; an 81% cure rate was seen from the objective pad test. Burch colposuspension Traditionally, Burch colposuspension (Figure 1) has been the surgical treatment of choice, with a success rate of 85% at 5 years, dropping to 70% thereafter. 22 Complications are voiding disorder (mean 10.3%), de novo detrusor overactivity (17%) and genitourinary prolapse (14%). 23 Lapitan et al. 19 concluded that open colposuspension was the most effective longterm surgical treatment for stress incontinence. There have been few studies comparing colposuspension with conservative management but these suggest a more favourable outcome for REVIEW Figure 1. Burch colposuspension Difficulties exist in obtaining high-quality evidence in continence surgery, as the literature 2004 Royal College of Obstetricians and Gynaecologists 161

4 REVIEW Figure 2. TVT trocar in position behind the symphysis pubis after the first pass (reproduced with permission from Gynecare ) Table 1. Comparison of organic versus synthetic traditional slings Sling complications Organic mesh Synthetic mesh Number of cases Retention (%) Detrusor overactivity (%) Urinary tract injury (%) Erosion (%) Revision (%) Removal (%) surgery. Continence rates appeared to be similar with both laparoscopic colposuspension and sling procedures. Burch colposuspension had better cure rates than the MMK procedure or paravaginal repair. 19 Laparoscopic colposuspension Laparoscopic surgery has the presumed advantage of avoiding a large incision, resulting in a shorter hospital stay and a quicker return to normal daily activities. Large differences in surgical techniques in this area confound comparison. There are few randomised controlled trials and these have limited follow-up. Moehrer et al. 24 assessed eight trials where, although the subjective outcomes appeared equal with colposuspension, there was some evidence of poorer outcomes over the longer term and on objective testing. Rates of detrusor overactivity and voiding disorders were unchanged. Although intraoperative time was longer, the recovery was quicker following the laparoscopic approach. Two sutures placed each side had a better success rate than a single suture. The role of laparoscopic colposuspension was thought to be unclear. It should only be attempted by a competent laparoscopic surgeon and should not be compromised by placing fewer sutures than would be the case in an open colposuspension. 24 In a subsequent powered randomised controlled trial,ankardal et al. 25 found a significantly greater subjective and objective cure increase in the open colposuspension group. Women undergoing laparoscopic colposuspension described a 74% objective cure, 62% subjective cure and 27% leakage-free rate, with a 9% prolonged retention rate. In the open colposuspension group, women described a 92% objective cure, 89% subjective cure and 57% leakage-free rate, with a 25% prolonged retention rate. In comparison with TVT, laparoscopic colposuspension is less successful at cure both subjectively and objectively. 26 However, on a cost analysis basis laparoscopic colposuspension was cheaper than TVT. 27 Sling procedures: classic open bladder neck sling There are two main types of sling procedure: the classic open bladder neck sling and the newer suburethral slings such as TVT. Success rates are approximately 80%, with little diminution over time, and tend to be higher with synthetic materials. However, their use increases the risk of erosion and sinus formation.the risk of voiding disorder is in the region of 10% and de novo detrusor overactivity is variable, at approximately 14%. 28 Table 1 compares traditional organic and synthetic slings. 29 Sling procedures: tension-free vaginal tape The newer suburethral tension free sling, typified by the TVT, is inserted vaginally at the level of the midurethra with exit points suprapubically (Figures 2 and 3). Careful adjustment is made to avoid placing the urethra under tension. The Gynecare TVT (Ethicon, Inc.) uses a monofilamentous type 1 mesh 30 and is associated with an 85% success rate, 2% voiding disorders requiring release of tape and 5% urgency. Insertion can typically be performed as day surgery. 31 The largest trial to date is a comparison of TVT with open colposuspension, 21 where 344 women were randomised (this was below the number specified by the power calculation of the study). Similar continence rates existed for both procedures, although there was a higher drop-out rate from the colposuspension group. There was a higher rate of self-catheterisation and prolapse surgery in the colposuspension group and a higher rate of 162 Gynaecologists 2004 Royal College of Obstetricians and

5 interoperative bladder perforation with TVT.While this is one of the best randomised controlled trials in the surgical management of stress incontinence, a criticism could be levelled that the study compared an operation carried out under general anaesthesia with one conducted under local anaesthesia. The difference in type of anaesthesia could influence perioperative morbidity. Following an assessment of quality adjusted life years comparing TVT with open colposuspension,tvt was found to be more cost-effective.the more expensive initial procedure cost was balanced by shorter duration of hospital stay, speedier recovery and reduced morbidity. 32 A report from the National Institute for Clinical Excellence 33 recommended the Gynecare TVT as a first-line procedure alongside Burch colposuspension in women for whom conservative management had failed and who were fully counselled. The report recommended that an appropriately trained surgeon perform the surgery. Bezerra et al. 34 did not differentiate between types of slings and failed to come to a conclusion as to their role at that time. Sling procedures: newer suburethral sling procedures Since the development of the TVT in 1996, there has been an explosion in marketing of similar devices using different mesh types and applicators. These have not generally been subjected to randomised controlled trials, have no long-term data from case-cohort studies and do not have the same evidence base. These devices cannot, therefore, be considered equivalent to the TVT procedure in terms of evidence-base. The TVT has been compared with suburethral tape, which uses the transobturator approach rather than supra-pubic. In total, 61 women were randomly assigned to either procedure. There were similar results at 1 year, although numbers were too small to reach significance. 35 A case-control series compared the TVT (69 women) with the suprapubic arc sling (37 women) (SPARC, American Medical Systems), where a monofilament tape can be passed from the suprapubic incisions down to the vagina rather than in the upwards direction of the TVT from vagina to suprapubic incisions. There were no significant differences for subjective cure between the two techniques. However, more positive pad tests were observed in the SPARC group while the TVT had a more negative effect on postoperative voiding.. A randomised controlled trial is in progress. 36 A case series of 104 women using SPARC showed subjective cure in 76%, voiding disorder in 10% and de novo urge in 10% Royal College of Obstetricians and Gynaecologists A comparison has been made with the intravaginal sling, where a similar procedure to TVT insertion is performed, but where a multifilamentous mesh is used. A random assignation of 100 women was made to either TVT or intravaginal sling, followed by 8 months of follow-up. There was a higher incidence of retention in the TVT group but no difference in cure or infection rate. 38 TVT has also been compared with a minimal access midurethral sling using a natural collagen implant (Pelvicol, Bard Ltd), where it was tied without tension across a strip of rectus muscle; 142 women were randomly assigned to either TVT or collagen implant sling and followed up within a median of 12 months. Patient-determined success rate was comparable for both groups. 39 It is important to realise that most of the new procedures have more marketing information REVIEW Figure 3. TVT in place before adjustment (reproduced with permission from Gynecare ) Figure 4. Periurethral injection 163

6 REVIEW Table 2. Comparison of surgical options Open Laparoscopic Classic colposuspension colposuspension sling TVT Injectable Success rate (%) Void dysfunction (%) De novo detrusor overactivity (%) than scientific support. Claims that these different anatomical approaches are safer have yet to be proven and statements that mesh type makes no difference contradict the basic scientific evidence in this area. 30 Periurethral bulking agents Bulking agents are injected into the urethral submucosa distal to the bladder neck to create artificial urethral coaptation and restore continence (Figure 4). Success rates vary with material used but deteriorate over time to about 50% at 2 years. 40 The procedure has low morbidity and may have a role when other procedures have failed or when the woman is unfit for surgery. There are many materials available for use. Pickard et al. 41 identified seven trials in this area but the limited data prevented meta-analysis. It was felt that further evidence of a patient benefit, costeffectiveness from randomised trials involving placebo and conservative treatment arms and comparison with colposuspension was required. 41 Conclusion on evidence-based surgical management Table 2 provides a comparison of the surgical options available. From the current evidence, TVT is the most cost-effective primary procedure, retaining the success rate and cure rate of open colposuspension but with decreased morbidity, a shorter hospital stay and quicker return to work. Five-year data show maintenance of benefit. 42 Although simple to perform in comparison with many of the other procedures, TVT still requires an appropriately trained surgeon as, otherwise, bladder perforation rates and voiding disorder rates can approach 20%. 43 The evidence base for the transobturator approach and different sling materials is lacking. The theoretical advantages of such new approaches need to be tested in the context of well-controlled clinical trials. However, longterm data are currently lacking and therefore these, in line with other new procedures, should be performed within a research setting. Each individual operation should have data on safety and outcome pertaining to its own product prior to introduction. At present there is no mechanism to control this. It is hoped that the specialist societies will make an attempt to act as coordinators for the introduction of new technologies. It must be remembered that continual adoption of new techniques subjects patients to continual learning curves. Still unclear is the best type of surgery to perform where there is concomitant prolapse, or where a previous continence operation has failed. It would seem sensible that all secondary procedures are carried out by an experienced urogynaecologist as the success rates are reduced and complications increased. 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