- Single-incision slings are as likely as mid-urethral slings to cure incontinence and may be associated with less pain.
- We are less certain about the differences between single-incision slings and other surgeries.
- Current evidence is largely limited to 2 years of follow-up. We need more long-term results to establish how effective and safe single-incision slings are compared to other surgical treatments.
What is urinary incontinence?
Urinary incontinence is when a person leaks urine by accident. It affects up to half of women over their lifetime. Stress urinary incontinence is urinary leakage that occurs during coughing, sneezing, or exercising. It is caused by weakness in the pelvic floor muscles that support the urethra (urine drainage tube from the bladder).
How is urinary incontinence treated?
It is treated first with exercises to strengthen the pelvic floor muscles. Around 1 in 10 women may need surgery.
All surgeries for urinary incontinence aim to support the bladder neck and the urethra. Surgery options vary in terms of how invasive they are, potential complications and recovery times. The most common surgeries today use a ‘sling’ which helps keep the urethra closed when there is sudden bladder pressure. Slings can be grouped into three categories:
- autologousslings: made from the patient’s own body tissue (fascia);
- standard mid-urethral slings: made from relatively long strips of polypropylene (plastic) mesh tape that are anchored in the surrounding tissues. Two common types are ‘retropubic slings’ and ‘transobturatorslings’. A key difference is in how the surgeon positions the tape.
- ‘single-incision slings’: made from relatively short strips of mesh tape, placed through a single cut inside the vagina.
For all polypropylene mesh slings, once the sling is in position, connective tissue grows through the holes in the mesh to anchor the sling in position.
In recent years, mesh slings have come under widespread public scrutiny and some have been withdrawn from the market.
What did we want to find out?
We wanted to learn how single-incision slings compare to other surgeries for urinary incontinence. We were interested in their effects on:
- curing or improving urinary incontinence;
- risk of pain and painful sex;
- risk of mesh erosions (exposure of or protrusion of tape into the vagina);
- urinary retention;
- risk of injuries and infections;
- need for further surgery;
- quality of life.
What did we do?
We searched for studies that compared single-incision slings to:
- other types of slings;
- other types of surgeries;
- conservative treatment (e.g. pelvic floor exercises) or no treatment.
We compared and summarised the studies’ results and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found 62 studies with 8051 women that compared single-incision slings to other sling surgeries. The women varied in age, weight and number of children born.
Ten studies received funding from industry or device manufacturers. Of these, 4 made a clear statement that industry sponsors were not involved in study design, conduct or writing. The remaining 6 studies provided few or unclear details.
One study compared single-incision to autologous slings and found that there is little difference between the 2 operations for the complications of painful sex and mesh exposure/erosions. The study did not report on other outcomes.
Single-incision versus retropubic slings: 10 studies
- There is little to no difference between these procedures for patient-reported cure or improvement of urinary incontinence.
- Single-incision slings may cause more mesh erosions compared to retropubic slings, but the evidence is uncertain.
- We do not know whether single-incision slings have any effect on the risk of urinary retention, the need for further surgery or quality of life compared with retropubic slings.
- There was no information on long-term pain or painful sex.
Single-incision versus transobturator slings: 51 studies
- Women who have single-incision slings are just as likely to have their incontinence cured or improved at 12 months as those with transobturator slings.
- Women with single-incision slings may have: (a) a similar number of mesh erosions and (b) the same risk of urinary retention, but (c) report less pain.
- We are uncertain whether single-incision slings affect the risk of painful sex.
- Women may have a slightly poorer quality of life at 12 months compared to women with transobturator slings.
- It is unclear whether the slings differ in the risk of needing further surgery later.
What are the limitations of the evidence?
Overall, we could not be certain of the results comparing single-incision slings to either autologous slings or retropubic slings because the studies were small and varied in important ways. We have more confidence in the substantial amount of evidence comparing single-incision to transobturator slings; this evidence is less likely to change with the publication of more trials.
How up to date is this evidence?
This review updates our previous version. The evidence is current to September 2022.
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.
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).
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.
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.
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.
We used standard Cochrane methodological procedures. The primary outcome was subjective cure or improvement of urinary incontinence.
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.