SLING PROCEDURE

The sling procedure, or suburethral sling procedure, refers to a particular kind of surgery using ancillary material to aid in closure of the urethral sphincter function of the bladder. It is performed as a treatment of severe urinary incontinence. The sling procedure, also known as the suburethral fascial sling or the pubovaginal sling, has many forms due to advances in the types of material used for the sling. Some popular types of sling material are Teflon (polytetrafluoroethylene), Gore-Tex®, and rectus fascia (fibrous tissue of the rectum). The surgery can be done through the vagina or the abdomen and some clinicians perform the procedure using a laparoscope - a small instrument that allows surgery through very small incisions in the belly button and above the pubic hairline. The long-term efficacy and durability of the laparoscopic suburethral sling procedure for management of stress incontinence are undetermined. A new technique, the Tension- Free Vaginal Tape Sling Procedure (TVT), has gained popularity in recent years and early research indicates high success rates and few postoperative complications. This procedure is done under local anesthetic and offers new opportunities for treatment of stress incontinence. However, TVT has not been researched for its long-term effects. Finally, there are many surgeons who use the sling procedure for all forms of incontinence.

Purpose
Incontinence is very common and not fully understood. Generally defined as the involuntary loss of urine, incontinence comes in many forms and has many etiologies. Four established types of incontinence, according to the Agency for Health Care Policy and Research, affect approximately 13 million adults—most of them older women. Actual prevalence may be higher because incontinence is widely underreported and underdiagnosed. The four types of incontinence are: stress incontinence, urge incontinence (detrusor overactivity or instability), mixed incontinence, and overflow incontinence. There are also other types of incontinence tied to specific conditions, such as neurogenic bladder in which neurological signals to the bladder are impaired.

Stress incontinence is the most frequently diagnosed form of incontinence and occurs largely with physical activity, laughter and coughing, and sneezing. The inability to hold urine can be due to weakness in the internal and external urinary sphincter or due to a weakened urethra. These two conditions, intrinsic sphincter deficiency (ISD) and urethral hypermobility or genuine stress incontinence (GSI), pertain to the inability of the “gatekeeper” sphincter muscles to stay taut and/or the urethra failing to hold urine under pressure from the abdomen. In women, as the pelvic structures relax due to age, injury, or illness, the uterus prolapses and the urethra becomes hypermobile. This allows the urethra to descend at an angle that permits loss of urine and puts pressure upon the sphincter muscles, both internal and external, allowing the mouth of the bladder to stay open.

Urge incontinence, the other frequent type of incontinence, pertains to overactivity of the sphincter in which the muscle contracts frequently, causing the need to urinate. Stress incontinence is often allied with sphincter overactivity and is often accompanied by urge incontinence.

Severe stress incontinence occurs most frequently in women younger than 60 years old. It is thought to be due to the relaxation of the supporting structures of the pelvis that results from childbirth, obesity, or lack of exercise. Some researchers believe that aging, perhaps due to estrogen deficiency, is a major cause of severe urinary incontinence in women, but no link has been found between incontinence and estrogen deficiency. Surgery for stress or mixed incontinence is primarily offered to patients who have failed, are not satisfied with, or are unable to comply with more conservative approaches. It is often performed during such other surgeries as urethra prolapse, cystocele surgery, urethral reconstruction, and hysterectomy.

The sling procedure gets its name from the tissue attached under the mid- or proximal urethra and sutured at its ends onto a solid structure like the rectus sheath, pubic bone, or pelvic side walls. The procedure is used in the severest cases of stress incontinence, particularly those that have a concomitant sphincter inadequacy (ISD). The sling supports the urethra as it receives pressure from the abdomen and helps the internal sphincter muscles to keep the urethral opening closed. The procedure is the most popular because it has the highest success rate of all surgical remedies for severe stress incontinence related to sphincter inadequacies in both men and women.

Demographics
Urinary incontinence (UI) plagues 10–35% of adults and at least half of the million nursing home residents in the United States. Other studies indicate that between 10% and 30% of women experience incontinence during their lifetimes, compared to about 5% of men. One reason that more women than men have incontinent episodes is the relatively shorter urethras of women. Women have urethras of about 2 in (5 cm) and men have urethras of 10 in (25.4 cm). Studies have documented that about 50% of all women have occasional urinary incontinence, and as many as 10% have regular incontinence. Nearly 20% of women over age 75 experience daily urinary incontinence. Incontinence is a major factor in individuals entering long term care facilities. Women at highest risk are those who have given birth to more than three children and women who were given oxytocin to induce labor.

Oxytocin puts more pressure on the pelvic muscles than does ordinary labor. Women who smoke have twice the rate of incontinence, according to one study of 600 women. Those women who do high-impact exercises are at much higher risk for incontinence. According to the medical literature, those at highest risk for urinary leakage are gymnasts, followed by softball, volleyball, and basketball players. Finally, women who have diabetes or are obese have higher rates of incontinence. Women who require sling procedures have often had other surgeries for incontinence, necessitating sling procedure to treat intrinsic sphincter deficiency caused by operative trauma. A rarer cause of stress incontinence in older women is urethral instability. In men, stress incontinence is usually caused by sphincter damage after surgery on the prostate.