|Tension-free midurethral slings in the treatment of female stress urinary incontinence: a systematic review and meta-analysis of randomized controlled trials of effectiveness
|Novara G, Ficarra V, Boscolo-Berto R, Secco S, Cavalleri S, Artibani W
This review concluded that tension-free vaginal tape outperformed Burch colposuspension, intravaginal slingplasty and the suprapubic arc for female stress urinary incontinence. Similar efficacy was observed for retropubic and trans-obturator tapes. There were limitations to this review but, overall, the authors appropriately concluded that there was insufficient good evidence to make recommendations for practice.
To evaluate the efficacy of tension-free vaginal tape (TVT) against other tension-free midurethral slings and other surgical treatments for stress urinary incontinence (SUI).
MEDLINE, EMBASE and Web of Science were searched in January 2007 using the search terms documented in the report. No date limits were imposed but searching was restricted to articles in English. The reference lists of included studies were checked for further studies.
The review focused on randomised controlled trials (RCTs) of female patients that evaluated tension-free midurethral slings. Studies were included if they assessed objective outcome measures such as stress test and pad test, or subjective measures such as the patients' perception of improvement as assessed by questionnaires or interview. The review compared TVT with other surgical treatments for SUI (e.g. Burch colposuspension, pubovaginal sling, intravaginal slingplasty and suprapubic arc) and compared TVT with other retropubic tension-free midurethral slings. The review assessed overall cure (using any definition of cure), objective cure (negative stress or pad test) and subjective cure.
Three authors were involved in selecting studies for the review.
Assessment of study quality
The quality of the included studies was assessed through the Jadad score, which assigns a value of 0 to 5 based on methods of randomisation, blinding and drop-outs. A score of 5 represented the highest methodological quality.
Two reviewers appear to have extracted data on quality from the studies, while one reviewer checked the accuracy of the quality assessment.
Where possible, the percentages of patients with overall, objective and subjective cure rates were reported for each treatment arm. For dichotomous data, odds ratios (ORs) were generated along with 95% confidence intervals (CIs).
Two reviewers extracted data from the studies and one reviewer checked the accuracy of the data extraction.
Methods of synthesis
The studies were combined using meta-analysis. The χ2 test was used to assess statistical heterogeneity, and in the absence of heterogeneity fixed-effect models were used for the analysis. Publication bias was assessed graphically using a funnel plot. A sensitivity analysis was conducted by limiting some analyses to studies with at least 12 months' follow-up.
Results of the review
Thirty-seven RCTs were included in the review; the total number of participants was unstated.
Eight RCTs were published as abstracts only. Most of the trials were of limited quality.
Nine RCTs compared retropubic tension-free midurethral tapes with Burch colposuspension. TVT was associated with significantly higher overall continence rates (OR 0.58, 95% CI: 0.42, 0.79), based on 8 RCTs.
Five RCTs, all of which were small and had methodological limitations, compared TVT with pubovaginal sling. No statistically significant differences were observed in the meta-analysis of overall cure rates.
Three RCTs compared TVT with intravaginal slingplasty. TVT was associated with a significantly higher overall cure rate (OR 0.51, 95% CI: 0.31, 0.83).
Four RCTs compared TVT with suprapubic arc. TVT was associated with a significantly higher objective cure rate when using any definition (OR 0.53, 95% CI: 0.34, 0.82). The exclusion of the largest RCT in the group, which had only a 2-month follow-up, resulted in a non significant difference between treatment groups.
Fourteen trials compared retropubic with trans-obturator tension-free midurethral slings. With the exception of one study, all were methodologically weak in terms of inaccurate randomisation and blinding procedures, were underpowered, had short follow-up, and some were published solely as abstracts. There were no statistically significant differences between treatment groups in terms of overall cure rate.
Full details of the results of meta-analyses of objective and subjective cure rates for all different treatments evaluated, in addition to sensitivity analyses, were given in the report.
TVT increased cure rates compared with Burch colposuspension, intravaginal slingplasty and suprapubic arc. The success rates were similar for TVT and pubovaginal slings. Similar efficacy was observed for retropubic and trans-obturator tapes. However, most of the studies were of limited quality, which limits the strengths of recommendations for practice.
The review question was broadly defined in terms of the participants, intervention, outcomes and study design. A more explicit definition of the inclusion criteria would have been helpful. The search involved a range of sources but was limited to studies written in English and published reports; this opens up the possibility of both language and publication bias. More than one reviewer was involved in selecting studies, assessing study quality and extracting the data, which helps to reduce the possibility of bias and error in these processes. There was no information about the participants in the included studies, which means it is not possible to determine the population to whom these results may be applicable. The Jadad quality scoring system, while limited, does highlight the major flaws in the included studies. The meta-analysis appeared appropriate, although the results were not always presented clearly. It appears that only statistical heterogeneity was assessed, and the role of any clinical heterogeneity in determining combinability for meta-analysis was unclear. There were limitaitons to this review but, overall, the authors appropriately concluded that the quality of the included studies was not sufficiently robust to determine strong recommendations for practice.
Implications of the review for practice and research
Practice: The authors did not state any implications for practice.
Research: The authors stated that further high-quality RCTs, using standardised criteria to evaluate continence and success rates after surgery, are needed.
Novara G, Ficarra V, Boscolo-Berto R, Secco S, Cavalleri S, Artibani W. Tension-free midurethral slings in the treatment of female stress urinary incontinence: a systematic review and meta-analysis of randomized controlled trials of effectiveness. European Urology 2007; 52(3): 663-679
Other publications of related interest
Novara G, Artibani W, Barber MD, Chapple CR, Costantini E, Ficarra V, Hilton P, Nilsson CG, Waltregny D. Updated systematic review and meta-analysis of the comparative data on colposuspensions, pubovaginal slings, and midurethral tapes in the surgical treatment of female stress urinary incontinence. European Urology 2010;58(2):218-238.
Novara G, Galfano A, Boscolo-Berto R, Secco S, Cavalleri S, Ficarra V, Artibani W. Complication rates of tension-free midurethral slings in the treatment of female stress urinary incontinence: a systematic review and meta-analysis of randomized controlled trials comparing tension-tree midurethral tapes to other surgical procedures and different devices. European Urology 2008;53(2):288-309.
Subject indexing assigned by NLM
Female; Humans; Prosthesis Design; Prosthesis Implantation /instrumentation; Randomized Controlled Trials as Topic; Suburethral Slings; Treatment Outcome; Urinary Incontinence, Stress /surgery
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.