Mid-urethral slings have become the most common method to treat stress urinary incontinence (SUI). They are typically placed in under 30 minutes in an outpatient setting and are popular with both physician and patients due to the high cure rate, relative ease of placement, low complication rate and quick recovery.
The prototype of modern day slings is the TVT (tension-free vaginal tape), and many similar ones exist on the market that are placed in a similar fashion, but ultimately perform the same function. TVT has been around for approximately 15 years and is used worldwide.
The sling is made of a thin strip of polypropylene mesh weave, a common and safe type of mesh used for surgery in a variety of body locations. The width is 1 cm and the length left in the body is usually between 6-8 inches long. There are various methods for placing slings, but ultimately, it must rest under the mid-urethra.
It is placed through a small incision in the vagina, usually under general anesthesia, and women can go home the same day without a urinary catheter after urinating in recovery. Vaginal stitches to close the skin dissolve, but the sling is permanent. It becomes incorporated into the body tissue. The body lays new collagen and scar within the sling and around it, and it becomes a new firm ligament under the urethra replacing the one that had become weak. The sling acts like a backboard and supports the urethra during straining maneuvers such as coughing, sneezing, laughing, jumping and exercise. It prevents it from descending, thereby preventing urine loss.
Slings are durable to about 10-15 years but longer term data does not exist simply because it hasn’t been around that long. It is less invasive than the next most popular procedure for SUI, the Burch colposuspension, which requires a bikini line abdominal incision and then the bladder neck is raised up and stitched close to the back part of the pubic bone. Despite equivalent cure rates, surgery time and recovery time is longer. It has generally fallen out of favor as a modern approach to curing SUI. If a woman is undergoing other pelvic surgery such as a hysterectomy or bladder lift (cystocele), a sling can be done concomitantly and adds only a few extra minutes to these procedures.
For those women who desire cosmetic vaginal surgery, sling surgery can be done as well at the same time.
The expected cure rate for slings is approximately 89-91% where the female patient is dry. There is about a 2% failure rate, and the rest can be considered improved. Improvement from soaking 6 pads a day to 2 thin liners is a success for severe cases of incontinence.
Durability is important and most (85%) will still be dry in the long term. There is an expected drop off (recurrence) rate which is inevitable given changes that occur to the body with age, menopause, weight loss or gain, etc. Women who are still considering another pregnancy should not undergo a sling till childbearing is complete.
Preoperative evaluation with a history, physical exam, urinalysis, and urodynamics help to make the appropriate decision as to whether: 1. A sling is appropriate and, 2. which type of sling to use. Other factors taken into consideration when deciding if/when/and how to place the sling include age, prior surgeries, body habitus, overall health, and other considerations. Bladder function, capacity, and sphincter function as determined by urodynamics helps to tailor the sling to the individual patient.
Common risks include: infection (low), bleeding (low), injury to bladder (low), mesh exposure in the vagina (low), and post operative urinary dysfunction. Vaginal spotting is expected for 1-2 weeks after the surgery.
Recovery is usually straightforward. Typically, being a “couch potato” for 72 hrs is recommended. Women can return to work thereafter (if non-physical). Exercise and exertion should be delayed about 2-3 weeks, but no pools, baths or sex for six weeks.
Slings will usually work right away even though most scarring isn’t complete for several months. In the first several weeks, occasionally the stream may seem a little slower than usual, or may split or deflect. These usually self correct after a few weeks.
There are women who experience leakage of urine with penetration during sex, and others who experience leakage of urine with orgasm. Several studies have shown that penetration-related leakage is treatable with TVT type slings. Orgasm-related leakage can be treated with overactive bladder medication, but one study did show TVT to help this as well. Urodynamic evaluation is important to verify the correct type of sex-related incontinence prior to treatment.
Despite the fact that TVT and other slings are placed in the vagina under the urethra, it has an overall beneficial effect on female sexual dysfunction when it is related to incontinence. Women may be embarrassed to have sex if they fear a urine leak or odor, and will avoid it or have decreased pleasure. Surgical correction of SUI with TVT has been shown to improve sexual function domains such as desire, arousal, lubrication, orgasm, satisfaction, and pain. As a result of the surgery, women report reacquiring self confidence and greater sexual interest after resolution of sex-related incontinence. The consensus in the literature concludes that there is a positive, not negative, impact on female sexual health.
Most women are motivated to cure SUI and will often first perform Kegel muscle exercises and restrict fluids, or urinate frequently to keep the bladder empty and avoid a leak. These can be successful strategies but are tedious and frustrating to many. Once these conservative options have been exhausted, evaluation for a sling can be performed.