Key messages

- 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In recent years, mesh slings have come under widespread public scrutiny and some have been withdrawn from the market.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.

Main results

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.