Midurethral Sling for Stress Urinary Incontinence

The midurethral sling is the most widely performed surgical treatment for stress urinary incontinence in women, with objective cure rates that exceed 85% at ten years in many studies. The procedure involves placing a narrow strip of synthetic mesh beneath the urethra to restore the support that keeps it closed during coughing, sneezing, or physical activity. Despite years of controversy over surgical mesh in general, the midurethral sling has maintained strong endorsements from major professional societies, and the evidence behind it is some of the deepest in all of pelvic surgery.

How the Sling Works

Stress urinary incontinence happens when the structures supporting the urethra weaken, usually after childbirth, hormonal changes, or aging. When you cough or jump, abdominal pressure pushes down on the bladder, and without adequate support the urethra cannot stay sealed. A midurethral sling addresses this by reinforcing the ligament that holds the urethra in place. According to the integral theory of continence, the sling acts like a replacement for the pubourethral ligament, preventing the urethra from opening outward and restoring closure at both the mid-urethra and the bladder neck.¹

The sling itself is typically a thin strip of knitted polypropylene mesh, roughly one centimeter wide. Over the weeks following surgery, your own tissue grows through the mesh pores, anchoring it in place. Flexible, macroporous polypropylene integrates more completely with surrounding tissue than denser or multifilament materials, which is why the design of the mesh matters as much as its placement.²

Retropubic Versus Transobturator Routes

The two standard approaches for placing a midurethral sling differ in how the mesh is anchored. The retropubic route (often called TVT, after the original brand name) threads the mesh behind the pubic bone. The transobturator route (TOT or TVT-O) passes the mesh through the inner thigh’s obturator foramen instead. Both have been studied extensively in head-to-head trials.

A large meta-analysis pooling data from dozens of randomized trials found that retropubic slings produced slightly higher cure rates than transobturator slings on both subjective and objective measures. But the transobturator approach had a lower risk of bladder perforation, pelvic blood collection, urinary tract infections, and post-operative voiding difficulty.³ When that analysis was restricted to trials with follow-up longer than five years, the two approaches performed similarly. One long-term prospective study, however, found a wider gap at extended follow-up: about 42% of retropubic patients had no stress incontinence at all, compared with roughly 22% in the transobturator group.⁴

The complication profiles are genuinely different rather than just slightly shifted. Bladder perforation during surgery occurs almost exclusively with the retropubic route, while nerve-related symptoms like thigh numbness or pain are more common after the transobturator approach.⁵ Which route a surgeon recommends depends on the individual case, including how severe the leakage is, whether you have had prior surgery, and your anatomy.

How Long the Results Last

Long-term data on midurethral slings is now extensive enough to give a realistic picture. Objective cure rates, meaning the sling prevents measurable leakage on a clinical test, exceeded 85–90% at ten years in retropubic cohorts and remained stable over time.⁶ What patients report about their symptoms is more variable. Some women develop new urgency symptoms or feel their incontinence has partially returned, even when clinical testing shows the sling is still working. The gap between objective measurements and subjective satisfaction is a consistent finding across studies and is worth knowing about before surgery.

A large comparative study with over 1,300 women and a mean follow-up exceeding ten years found that about 85% of retropubic sling patients reported no ongoing stress incontinence, a figure statistically similar to the 83% seen with Burch colposuspension, a more traditional open surgery. Patient-reported satisfaction and quality-of-life scores were also comparable between the two procedures.⁷ The sling achieves similar long-term results through a much less invasive operation, which is a major reason it became the dominant approach.

Single-Incision Mini-Slings

The newest evolution of the midurethral sling is the single-incision mini-sling, which uses a shorter piece of mesh anchored through a single vaginal cut instead of threading tape through the abdomen or thigh. A well-powered randomized trial published in the New England Journal of Medicine found that adjustable anchored mini-slings were noninferior to standard midurethral slings, with about 79% of mini-sling patients reporting success at 15 months versus roughly 76% in the standard group. At three years, the rates were about 72% and 67%, respectively.⁸

A recent meta-analysis of randomized trials went further, finding that mini-slings had a slight edge in objective cure rates and offered meaningful practical advantages: shorter operative time (about six and a half minutes less), shorter hospital stays, lower pain scores on the first day after surgery, less intraoperative organ injury, and less postoperative bleeding. On measures like quality of life, patient-reported cure, sling erosion, and reoperation rates, the two types performed similarly.⁹

One signal to watch, though, is dyspareunia (pain during intercourse). In the SIMS trial, about 12% of mini-sling patients reported it at three years, compared with roughly 5% in the standard sling group.¹⁰ That difference is clinically meaningful, and it is worth discussing with your surgeon if sexual comfort is a priority for you.

Complications and Mesh Safety

The midurethral sling has been caught up in the broader mesh controversy, largely because vaginal mesh used for pelvic organ prolapse repair had unacceptably high complication rates. The distinction matters: the sling is a narrow strip placed in a very different anatomical location, and its complication profile is substantially better. FIGO, the international federation of obstetricians and gynecologists, has stated that the synthetic mesh midurethral sling is considered safe and effective for stress urinary incontinence based on extensive high-quality evidence, even while acknowledging that mesh for prolapse repair remains controversial.¹¹

That does not mean slings are complication-free. The most common issues include:

Mesh exposure: The mesh can erode through the vaginal wall or, more rarely, into the urethra. Urethral exposure is often diagnosed late, averaging over three years after surgery, because its symptoms (recurrent infections, discomfort, spraying urine) are nonspecific and easily attributed to other causes.¹²
Voiding difficulty: Some women have trouble emptying their bladder after surgery if the sling is too tight. This usually resolves within weeks but occasionally requires loosening or partial removal.
Bladder perforation: With the retropubic route, the needle can pass through the bladder wall. Surgeons check for this during the procedure with a cystoscope and manage it immediately, so it rarely causes lasting harm.

When mesh complications do require removal, the approach affects your continence afterward. A systematic review found that partial mesh removal had about half the odds of causing recurrent stress incontinence compared with total removal. Both methods were similar in resolving pain, obstruction, and other mesh-related symptoms.¹³ The practical takeaway is that if you need sling revision, partial removal preserves function better in most cases.

Sexual Function After the Sling

Many women worry that sling surgery will affect their sex life, but the overall picture is positive. One study of nearly 300 women found that roughly the same proportion were sexually active before and after surgery (86% vs 83%), and women whose incontinence was cured were more likely to remain sexually active. Coital incontinence, which affects about half of women with stress urinary incontinence, dropped dramatically to around 7% after surgery.¹⁴ That study also found de novo dyspareunia in about 9% of cases, which is consistent with what other trials have reported.

Longer follow-up data paints a reassuring picture as well. At three years, standardized sexual function scores showed no significant change from before surgery.¹⁵ And at 10 to 20 years out, women reported less negative impact of incontinence on their sexual lives than before surgery. Only about 3–4% of women had persistent pain after the sling at that timepoint, and the pain was not associated with being sexually inactive, suggesting that untreated incontinence itself has a larger negative effect on sexual life than lingering post-surgical pain.¹⁶

When Incontinence Is Mixed

Not everyone with leakage has pure stress incontinence. Mixed urinary incontinence, where you leak both with physical effort and with sudden urges to urinate, is common and complicates the picture. A midurethral sling fixes the stress component well, but the urgency side is less predictable. Studies report that urgency symptoms improve in 30–85% of women with mixed incontinence, though the benefit often fades over time.¹⁷

Certain factors predict who will continue to have urgency after surgery. In a large prospective study, women with detrusor overactivity (involuntary bladder muscle contractions seen on urodynamic testing) had about double the risk of persistent urgency and urge incontinence after a sling. Older age and more severe baseline symptoms also increased that risk, while having prolapse repaired at the same time actually decreased it.¹⁸ If urgency is your dominant symptom, your surgeon may recommend trying medications or behavioral therapy for that component before or alongside sling surgery.

Synthetic Slings Versus Autologous Tissue

Before synthetic midurethral slings existed, the pubovaginal sling using a woman’s own tissue (usually a strip of abdominal fascia) was the gold standard. These autologous slings are still performed, especially in places where synthetic mesh is restricted or when a patient wants to avoid mesh entirely. A meta-analysis comparing the two found that synthetic retropubic slings were associated with higher subjective continence rates in populations where at least a quarter of patients had recurrent stress incontinence, and satisfaction was also better with synthetic transobturator slings compared to autologous ones.¹⁹

However, a separate systematic review looking specifically at autologous fascia slings placed at the mid-urethra (rather than the traditional bladder neck position) found that objective and subjective cure rates were similar to those of synthetic retropubic slings, with comparable complication profiles. The main trade-off was longer operative time for the autologous approach, since harvesting fascia adds a surgical step.²⁰ Another meta-analysis confirmed that at medium and long-term follow-up, autologous rectus fascia grafts provided similar continence results and complication rates to synthetic mesh slings.²¹ The autologous approach is a legitimate alternative with good outcomes, though the data behind it is thinner than for synthetic slings.

Bulking Agents as a Less Invasive Alternative

Urethral bulking agents are injectable materials placed around the urethra to help it seal. They are less invasive than a sling, done in an office setting, and avoid mesh entirely. Their efficacy ranges from roughly 64–74%, compared with up to 80% for midurethral slings.²² They are typically used when a sling is not an option, such as in women with significant medical comorbidities or those who want to avoid surgery.

The trade-off is durability. A large study of older women found that those who received bulking agents had nearly four times the risk of needing a second procedure compared with those who got a sling.²³ Over a one-year time horizon, however, bulking agents can be more cost-effective in specific situations. One analysis found that for women without urethral hypermobility (meaning the urethra doesn’t move much with straining), bulking agents cost substantially less per patient than a sling, and the additional effectiveness of the sling did not justify the extra expense at a standard willingness-to-pay threshold.²⁴ The question of which option is right depends heavily on your anatomy, how much leakage you have, and how you feel about possibly needing repeat treatments.

Pregnancy After a Midurethral Sling

Some younger women have sling surgery before they are finished having children, which raises the natural question of whether pregnancy and delivery will undo the repair. A systematic review and meta-analysis found that about 22% of women had recurrent stress incontinence after childbirth following a prior sling, and roughly 5% needed a repeat procedure. But here is the key finding: there was no statistical difference in recurrence or reintervention rates between women who delivered after a sling and those who did not. Vaginal versus cesarean delivery also made no difference.²⁵

That said, a registry study found that women who delivered after a sling were more likely to have cesarean sections (about 43% after the sling vs 9% before), suggesting that clinicians or patients often choose surgical delivery to protect the repair, even though the evidence does not clearly show it helps.²⁶ A body mass index of 30 or above and having incontinence during the pregnancy itself were risk factors for postpartum relapse.

Do You Need Urodynamic Testing Before Surgery

Urodynamic testing is a set of bladder pressure and flow measurements that some doctors order before recommending a sling. It can identify conditions like detrusor overactivity or poor bladder emptying. But a landmark randomized trial of 630 women found that adding urodynamic testing to a standard office evaluation made no difference in surgical success rates, which were about 77% in both groups. There were also no differences in complication rates, quality of life, or patient satisfaction.²⁷ Women who had the testing were more likely to receive a diagnosis of voiding dysfunction, but this did not change what treatment they received or how they did.

A separate cost-effectiveness analysis concluded that urodynamic testing before surgery was not cost-effective relative to a basic office evaluation when the prevalence of pure detrusor instability was below 8%, or when the test itself cost more than about $100.²⁸ For most women with straightforward stress incontinence symptoms, a careful clinical evaluation by an experienced surgeon is sufficient to decide whether a sling is appropriate.

Anesthesia and Outpatient Setting

Midurethral sling procedures are almost always outpatient, with most women going home the same day. They can be done under general anesthesia, spinal or epidural anesthesia, or local anesthesia with sedation. The choice of anesthesia affects one practical concern in particular: the ability to urinate after surgery. Women who received regional anesthesia (spinal or epidural) had about four times the odds of temporary urinary retention afterward compared with those who had nonregional anesthesia.²⁹ Retention usually resolves within a day or two but can delay discharge or require a catheter.

Mini-slings in particular have been performed under local anesthesia alone in office-like settings. A feasibility study reported that patients rated intraoperative pain at just 2 out of 10, and all were satisfied with the experience. No serious complications occurred during the procedures.³⁰ While local anesthesia is not suitable for every patient or every sling type, the trend toward less invasive anesthesia aligns with the overall push to make sling surgery simpler and faster to recover from.

When Adding Pelvic Floor Therapy Makes Sense

Pelvic floor muscle training (often called Kegel exercises when done in a structured program with a therapist) is the standard first-line treatment for stress urinary incontinence. But what about combining it with surgery? A cost-effectiveness analysis from the ESTEEM trial found that for the general population of women having sling surgery, adding preoperative behavioral and pelvic floor therapy to the sling did not improve outcomes enough to justify its cost. However, for women whose urgency symptoms were more severe at baseline, the combined approach was cost-effective from both health-system and societal perspectives.³¹ A separate analysis comparing initial treatment with pelvic floor training alone versus proceeding straight to a midurethral sling found the sling to be cost-effective at roughly $32,000 per quality-adjusted life year gained.³² These figures are well within the threshold that health systems typically consider good value, which underscores why guidelines generally recommend trying pelvic floor therapy first but support proceeding to surgery if conservative measures are not enough.