Single-incision sling operations for urinary incontinence in women

BACKGROUND

Stress urinary incontinence imposes a significant health and economic burden on individuals and society. Single-incision slings are a minimally-invasive treatment option for stress urinary incontinence. They involve passing a short synthetic device through the anterior vaginal wall to support the mid-urethra. The use of polypropylene mesh in urogynaecology, including mid-urethral slings, is restricted in many countries. This is a review update (previous search date 2012).

OBJECTIVES

To assess the effects of single-incision sling operations for treating urinary incontinence in women, and to summarise the principal findings of relevant economic evaluations.

SEARCH METHODS

We searched the Cochrane Incontinence Specialised Register, which contains trials identified from: CENTRAL, MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, and two trials registers. We handsearched journals, conference proceedings, and reference lists of relevant articles to 20 September 2022.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials in women with stress (or stress-predominant mixed) urinary incontinence in which at least one, but not all, trial arms included a single-incision sling.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. The primary outcome was subjective cure or improvement of urinary incontinence.

MAIN RESULTS

We included 62 studies with a total of 8051 women in this review. We did not identify any studies comparing single-incision slings to no treatment, conservative treatment, colposuspension, or laparoscopic procedures. We assessed most studies as being at low or unclear risk of bias, with five studies at high risk of bias for outcome assessment. Sixteen trials used TVT-Secur, a single-incision sling withdrawn from the market in 2013. The primary analysis in this review excludes trials using TVT-Secur. We report separate analyses for these trials, which did not substantially alter the effect estimates. We identified two cost-effectiveness analyses and one cost-minimisation analysis. Single-incision sling versus autologous fascial sling One study (70 women) compared single-incision slings to autologous fascial slings. It is uncertain if single-incision slings have any effect on risk of dyspareunia (painful sex) or mesh exposure, extrusion or erosion compared with autologous fascial slings. Subjective cure or improvement of urinary incontinence at 12 months, patient-reported pain at 24 months or longer, number of women with urinary retention, quality of life at 12 months and the number of women requiring repeat continence surgery or sling revision were not reported for this comparison. Single-incision sling versus retropubic sling Ten studies compared single-incision slings to retropubic slings. There may be little to no difference between single-incision slings and retropubic slings in subjective cure or improvement of incontinence at 12 months (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.07; 2 trials, 297 women; low-certainty evidence). It is uncertain whether single-incision slings increase the risk of mesh exposure, extrusion or erosion compared with retropubic minimally-invasive slings; the wide confidence interval is consistent with both benefit and harm (RR 1.55, 95% CI 0.24 to 9.82; 3 trials, 267 women; low-certainty evidence). It is uncertain whether single-incision slings lead to fewer women having postoperative urinary retention compared with retropubic slings; the wide confidence interval is consistent with possible benefit and harm (RR 0.47, 95% CI 0.12 to 1.84; 2 trials, 209 women; low-certainty evidence). The effect of single-incision slings on the risk of repeat continence surgery or mesh revision compared with retropubic slings is uncertain (RR 4.19, 95% CI 0.31 to 57.28; 2 trials, 182 women; very low-certainty evidence). One study reported quality of life, but not in a suitable format for analysis. Patient-reported pain at more than 24 months and the number of women with dyspareunia were not reported for this comparison. We downgraded the evidence due to concerns about risks of bias, imprecision and inconsistency. Single-incision sling versus transobturator sling Fifty-one studies compared single-incision slings to transobturator slings. The evidence ranged from high to low certainty. There is no evidence of a difference in subjective cure or improvement of incontinence at 12 months when comparing single-incision slings with transobturator slings (RR 1.00, 95% CI 0.97 to 1.03; 17 trials, 2359 women; high-certainty evidence). Single-incision slings probably have a reduced risk of patient-reported pain at 24 months post-surgery compared with transobturator slings (RR 0.12, 95% CI 0.02 to 0.68; 2 trials, 250 women; moderate-certainty evidence). The effect of single-incision slings on the risk of dyspareunia is uncertain compared with transobturator slings, as the wide confidence interval is consistent with possible benefit and possible harm (RR 0.78, 95% CI 0.41 to 1.48; 8 trials, 810 women; moderate-certainty evidence). There are a similar number of mesh exposures, extrusions or erosions with single-incision slings compared with transobturator slings (RR 0.61, 95% CI 0.39 to 0.96; 16 trials, 2378 women; high-certainty evidence). Single-incision slings probably result in similar or reduced cases of postoperative urinary retention compared with transobturator slings (RR 0.68, 95% CI 0.47 to 0.97; 23 trials, 2891 women; moderate-certainty evidence). Women with single-incision slings may have lower quality of life at 12 months compared to transobturator slings (standardised mean difference (SMD) 0.24, 95% CI 0.09 to 0.39; 8 trials, 698 women; low-certainty evidence). It is unclear whether single-incision slings lead to slightly more women requiring repeat continence surgery or mesh revision compared with transobturator slings (95% CI consistent with possible benefit and harm; RR 1.42, 95% CI 0.94 to 2.16; 13 trials, 1460 women; low-certainty evidence). We downgraded the evidence due to indirectness, imprecision and risks of bias.

AUTHORS' CONCLUSIONS

Single-incision sling operations have been extensively researched in randomised controlled trials. They may be as effective as retropubic slings and are as effective as transobturator slings for subjective cure or improvement of stress urinary incontinence at 12 months. It is uncertain if single-incision slings lead to better or worse rates of subjective cure or improvement compared with autologous fascial slings. There are still uncertainties regarding adverse events and longer-term outcomes. Therefore, longer-term data are needed to clarify the safety and long-term effectiveness of single-incision slings compared to other mid-urethral slings.

Is There Outcome Reporting Heterogeneity in Trials That Aim to Assess the Effectiveness of Surgical Treatments for Stress Urinary Incontinence in Women?

CONTEXT

Inconsistent reporting of effectiveness outcomes in surgical trials of stress urinary incontinence (SUI) has hindered direct comparisons of various surgical treatments for SUI.

OBJECTIVE

To systematically review the verbatim outcome names, outcome definitions, and tools used to measure the outcomes in surgical trials of SUI in women.

EVIDENCE ACQUISITION

Trials of women with SUI who have undergone surgical interventions were included. We conducted a systematic review (SR) on outcomes reported in randomized controlled trials of surgical management published in 2014-2019, covering the following databases: MEDLINE, EMBASE, CENTRAL, and CDSR. Verbatim outcome names extracted from the included studies were categorized and then grouped into domains using the Williamson-Clarke (W/C) outcome taxonomy. A matrix was also created to visualize and quantify the dimensions of outcome reporting heterogeneity in SUI trials.

EVIDENCE SYNTHESIS

A total of 844 verbatim outcome names were extracted, of which, 514 varied terms were reduced to 71 standardized outcome names. They were further categorized into 11 domains from the W/C taxonomy. There were 7.24 different terms on average to describe each outcome, and the four outcomes with the most heterogeneity evident in terms used to describe them were "urinary retention", "reoperation", "subjective cure rate" and "quality of life". Each of them had ≥20 different terms. Only 28% of the outcome definitions were reported and a variety of measuring tools was noted, particularly in subjective outcomes. High heterogeneity was found in the outcome names, outcome definitions, choice and number of measuring instruments of the outcomes, and choice and number of outcomes reported across studies.

CONCLUSIONS

This SR provides objective evidence of heterogeneity in outcome reporting in SUI surgical trials. Our categorization of outcomes highlights the difficulties in summarizing the current evidence base. A core outcome set, developed using the methods advocated by the Core Outcome Measures in Effectiveness Trials (COMET) and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiatives, is required.

PATIENT SUMMARY

In this research, we have highlighted the diversity in outcomes reporting in stress urinary incontinence (SUI) surgical trials and have categorized the outcomes. We support the development of a core outcome set for SUI, which will promote future clinical researchers to measure the same outcome in the same way in all trials. This will, in turn, help researchers summarize the evidence more effectively and aid decision making for patients and doctors.