Mid Urethral Sling Complications: Risks and Management

A mid-urethral sling is a narrow strip of polypropylene mesh placed under the urethra to stop leaking when you cough, laugh or exercise. It is one of the most effective and most studied operations for this kind of leaking.¹ It has also drawn heavy public worry, much of which stems from a different use of vaginal mesh, for prolapse, which regulators have treated far more cautiously than slings.² Most sling problems are short-lived and fixable, while a smaller share become long-term and need more careful treatment. Which problems you are most likely to face depends largely on the path the sling takes through the body.

How Often Problems Happen With Each Type of Sling

A retropubic sling (often called TVT) passes up behind the pubic bone toward the lower belly. A transobturator sling (often called TOT or TVT-O) runs out toward the inner thighs through the groin. A single-incision mini-sling uses one small vaginal cut and short arms. Each route has its own risks.

Because the retropubic route is passed blind past the bladder, it is the one that can puncture the bladder, in about 1 to 11 of every 100 operations.³ In a large trial, bladder puncture happened only with retropubic slings, and heavy bleeding during surgery was twice as common with them.⁴ Rare serious injuries to the bowel or large blood vessels, and very rarely death, have also been reported with this route.⁵ A puncture is usually fixed on the spot. Surgeons look inside the bladder with a camera to catch one, and if they find it, the needle is withdrawn and passed again right away. Most women then have a catheter for a short time and no lasting harm.

Transobturator slings avoid that space but caused more nerve-related symptoms, about 10 in 100 versus 5 in 100 for retropubic.⁶ Mesh exposure was also more common after transobturator slings, about 9 in 100 versus about 3 in 100.⁷

Effectiveness shapes the trade-off. Retropubic slings and slings made of your own tissue cured leaking in about 89 of 100 women, ahead of transobturator slings at about 64.⁸ Mini-slings work about as well as standard slings for straightforward stress leaking, take less operating time and cause less groin pain, but they are linked to more pain during sex.⁹ A mini-sling’s short arms rely on anchoring in tissue rather than a long path, and its long-term track record is shorter. That is a fair reason to ask a surgeon which specific mini-sling product they use and what is known about it.

These percentages come from different studies with different follow-up times and definitions, so small gaps should not be read as exact predictions for any one woman. Cure rates also depend on how cure is defined, whether no leaking at all or leaking much improved, which is part of why studies disagree.

If you are not sure which sling you had, your operation note or discharge letter usually names the device or route, such as TVT, TOT or TVT-O. Small scars above the pubic bone suggest a retropubic sling, and scars in the groin crease a transobturator one, though the operation record is the dependable answer. This matters later because loosening or removal is planned differently for each. Your surgeon’s office can send you the operation record.

Trouble Emptying the Bladder After Surgery

If the sling is set too tight, it partly blocks the urethra, causing a weak stream or being unable to empty.¹⁰ Retention after retropubic slings ranges up to about 11 in 100 women in some reports.¹¹ Most cases are temporary and clear up on their own within days.¹² In a very large national group, about 3 in 100 women needed some treatment for retention.¹³

In the first days, tell your surgical team about a slow or stop-start stream that is clearly worse than before, or the feeling that you still need to go right after peeing. Repeated urine infections can follow incomplete emptying. Lower belly fullness or pain, or being unable to pass urine at all, needs same-day care.

The first step is usually self-catheterization, passing a thin tube into the bladder yourself several times a day.¹⁴ A nurse teaches it, usually in one session. The tubes are thin, single-use and often prelubricated. Many women find self-catheterizing awkward at first but manageable, and it is usually a short bridge while things settle.

If self-catheterizing is still needed after this short bridge, the surgeon can loosen the sling or cut it.¹⁵ Women whose sling was loosened early did better, more often stayed dry and were more often very satisfied than those who catheterized first.¹⁶ Cutting the sling led to worse results than loosening it.¹⁷ So asking early about loosening, rather than waiting weeks, may protect your result.

Mesh Exposure and Mesh in the Urethra

After placement, the body’s healing reaction grows tissue into the mesh holes, anchoring it.¹⁸ Light, wide-hole, knitted polypropylene heals in best, while some older types healed in poorly.¹⁹ Infection and bacterial films on the mesh can disturb that healing.²⁰ When healing fails, mesh can become exposed through the vaginal wall. This is called mesh exposure, and your doctor or records may also call it erosion.

Exposure can feel like unusual discharge or spotting, sometimes long after surgery. A partner may feel a scratchy or sharp edge during sex. Some women have no symptoms at all and it is found only at a check-up. It can appear months or years after the operation, because healing around mesh is not a single event. Hormone changes after menopause can thin the vaginal tissue covering the mesh, and friction during sex or an infection can wear through tissue that held for years.

Some women are at higher risk. Previous pelvic surgery raised the odds of mesh exposure about tenfold.²¹ Diabetes raised the odds about four to five times and smoking about three times.²² Obesity and being past menopause each roughly doubled the odds.²³ Stopping smoking and controlling blood sugar before surgery are worth discussing with your surgeon.

A small exposure may be treated first with vaginal estrogen cream to help tissue cover it. If it doesn’t heal, the exposed piece is trimmed in a minor procedure. Larger or repeated exposures may need more mesh removed.

Mesh that wears into the urethra shows up differently. In one series, two-thirds of women had urine infection symptoms, half had urgent, frequent peeing, and about 4 in 10 had their leaking return.²⁴

Groin Pain, Pelvic Pain and Pain During Sex

Transobturator slings more often cause groin pain early on, but it usually goes away without treatment.²⁵ Most nerve symptoms were mild and gone by six weeks, though a few women still had them two years later.²⁶ In rare cases the tape traps or cuts a branch of a nerve in the groin, causing lasting pain.²⁷

Long after surgery, about 3 to 5 in 100 women reported persistent pain linked to the sling, with no clear difference between routes.²⁸ Overall sexual function was unchanged three years after surgery.²⁹ Ten years on, about 15 to 17 in 100 women reported pain with sex, similar for both main routes.³⁰ That pain was tied more to factors like menopause and higher weight than to the sling type.³¹

Pelvic floor muscles can tighten and hurt after surgery, producing groin or pelvic pain even when the sling sits well. Bladder pain syndrome or vaginal dryness after menopause can start or worsen around the same time. Pain does not automatically mean the mesh is the problem, and checking other causes can spare some women an operation.

Groin or inner-thigh pain still present after about six weeks deserves a review. So does pain that shoots down the leg or worsens with walking or lifting the leg, and new pain during sex for you or your partner. A simple pain diary helps the doctor judge the pattern.

To find where the mesh sits, an ultrasound shows the sling under the urethra well. An MRI shows the arms in the groin or behind the pubic bone better and can show infection. Neither can always tell scar from mesh, so an exam matters too.

Loosening, Cutting or Removing the Sling

Non-surgical care worked poorly for persistent or severe sling problems.³² Surgery is usually considered when symptoms persist despite medicines, physiotherapy or creams.

Each type of revision does something different. Loosening usually means going back in through the vaginal cut and pulling the sling looser or stretching it, a short operation. Cutting divides the tape in the middle so the arms stay in place but no longer press on the urethra. Partial removal takes out the central part under the urethra, and full removal also means chasing the arms through the groin or behind the pubic bone, which is a bigger operation.

The trade-off is leaking. Within 3 months of revision, leaking came back in about 8 in 100 after loosening, 22 after cutting, 60 after partial removal and 67 after full removal.³³ It came back far less often when the revision was for emptying problems than for other reasons.³⁴ Removing only part of the sling led to less leaking afterward than removing it all, about 19 versus 49 in 100.³⁵ But for painful slings, full removal relieved pain in about 63 in 100 women versus 26 with partial removal.³⁶

After revision, only about a quarter to a third of women had no urinary symptoms at all, most others having mild to moderate ones.³⁷ About 1 in 5 later had another anti-leak operation.³⁸ Younger women and those without urgency before revision were more likely to do well.³⁹ Removal treats the mesh problem but does not reset the bladder, and nerve pain may improve slowly or not completely. Leaking that returns can be treated with another sling or a non-mesh operation.

Before revision, ask how much mesh will be removed and why that amount, and whether it is done through the vagina, the groin, the belly or a combination. Ask about your chance of leaking afterward and what would treat it, and how many sling removals the surgeon does each year.

How Your Surgeon’s Experience Affects Risk

Surgeons doing more than 40 slings a year had slightly fewer repeat operations, about 3.6 versus 4.2 in 100.⁴⁰ Women treated by lower-volume surgeons were about a quarter more likely to need mesh removal or revision.⁴¹ The benefit levelled off beyond about 110 slings a year, and the surgeon’s specialty did not affect results.⁴² That gap of 3.6 versus 4.2 is modest, so a surgeon below 40 a year is not necessarily unsafe.

You can ask how many slings the surgeon places and removes each year, and what their own complication and repeat-surgery rates are. Ask whether they offer all sling types and non-mesh options. A specialist in pelvic floor or urogynecology often sees more cases.

Non-Mesh Options and Making the Decision

A fascial sling uses a strip of your own tissue, usually from the belly wall.⁴³ It is a longer, harder operation with more early emptying problems, but long-term success is high with very little risk of mesh-type complications like erosion and chronic pain.⁴⁴ In one trial, none of the women with fascial slings needed repeat surgery for leaking, versus about 3 in 100 with mesh tape.⁴⁵ Fascial slings did have about 3.6 times the odds of problems within 30 days of surgery.⁴⁶

Taking tissue from the belly wall means an extra cut, so recovery is usually longer and there can be pain at that site. Fewer surgeons offer it, so you may need a referral.

Other non-mesh operations exist. Bulking injections place a material beside the urethra through a small camera procedure, a lower-risk option though the effects tend to be less lasting. Colposuspension is an open or keyhole operation that lifts the tissue beside the urethra with stitches and uses no mesh. Both are less common than mesh slings, so availability depends on whether a local surgeon performs them.

Supervised pelvic floor training is usually offered before any surgery. It has no surgical risks and helps many women with mild leaking, but on its own it rarely cures stronger leaking, which is why surgery is offered.

Your own risk profile can guide the choice. Previous pelvic surgery, diabetes or smoking raise mesh exposure risk, which may tip you toward non-mesh options. If avoiding pain with sex is a priority, discuss the mini-sling’s higher risk. If bladder injury worries you more, transobturator routes avoid that space, though they carry more groin pain and lower cure rates.

Decision aids help women weigh every option and material risk before surgery.⁴⁷ Ask for written information covering all options, including physiotherapy, before you agree.