SLING PROCEDURE 2

Description of sling procedure : Anti-incontinence surgery is used to address the failure of two parts of female urinary continence: loss of support to the bladder neck or central urethra and intrinsic sphincter deficiency (ISD). The surgery does not restore function to the urethra or to the ability for closure to the sphincter. It replaces the mechanism for continence with supporting and compressive aids. Stabilizing the supporting elements of the urethra (ligaments, fascia, and muscles) was thought for many years to be the most important factor in curing incontinence. Called anatomic or genuine stress urinary incontinence (SUI), retropublic procedures, like the Burch procedure, sought only to restore the urethra to a fixed position. However, it became clear with the high failure rate of these procedures that ISD was present and unless surgery could confer some added compressive ability to the closure of the bladder, SUI would persist.

The urethral sling procedure is effective in the treatment of the severest types of incontinence (Types II and III) by re-establishing the “hammock effect” of the proximal or central point of the urethra during abdominal straining. The surgery involves the placement of a piece of material under the urethra at its arterial or vesical juncture and anchoring it on either side of the pubic bone or to the abdominal wall or vaginal wall. This technique involves the creation of a sling from a strip of tissue from the patient’s own abdominal fascia (fibrous tissue) or from a cadaver. Synthetic slings also are used, but some are prone to break down over time.

The urethral sling procedure is most often performed as open surgery, which involves entering the pelvic area from the abdomen or from the vagina while the patient is under general or regional anesthesia. Broad-spectrum antibiotics are offered intravenously. If the patient is fitted with a urethral catheter, ampicillin and gentamicin are administered instead. The patient is placed in stirrups. Surgery takes place as a 6-to-9-cm by 1.5-cm sling is harvested from rectal tissue and sutured under the urethra at each end within the retropubic space (the area that undergirds the urethra). Synthetic tissue or fascia from a donor may also be used.

The goal of the surgery is to create a compression aid to the urethra. This involves an individualized approach to the tension needed on the sling. While the sling procedure is relatively easy to complete, the issue of tension on the sling is hard to determine and involves the use of tests during surgery for determining the compression effect of the sling on the urethra. Some manual tests are performed or a more sophisticated urodynamic test, like cystourethrography, may determine tension. It is important for the surgeon to test tension during surgery because of the high rate of retention of urine (inability to void) after surgery associated with this procedure and the miscalculation of the required tension.

Diagnosis / Preparation
Candidates for surgical treatment of incontinence must undergo a full clinical, neurological, and radiographic evaluation before there can be direct analysis of the condition to be treated and the desired outcome. Both urethral and bladder functions are evaluated and there is an attempt to determine the conditions associated with stress incontinence. In many women, incontinence may be due to vaginal prolapse. Stress incontinence can be identified by observation of urine during pelvic examination or by a sitting or standing stress test where patients are asked to cough or strain and evidence of leakage is obtained. Gynecologists often use a Q-tip test to determine the angle and change in the position of the urethra during straining. Other tests include subtracted cystometry to measure how much the bladder can hold, how much pressure builds up inside the bladder as it stores urine, and how full it is when the patients feels the urge to urinate.

The frequency of stress incontinence as measured by typical symptoms ranges between 33% and 65%. The frequency of stress incontinence is around 12% when measured or defined by cystometric findings. The ability to distinguish SUI as the cause of incontinence, as opposed to ISD, becomes more complicated; but it is a very important factor in the decision to have surgery. A combination of pelvic examination for urethral hypermoblity and leak point pressure as measured by coughing or other abdominal straining has been shown to be very effective in distinguishing ISD, and identifying the patient who needs surgery.

Aftercare
IV ketorolac and oral and intravenous pain medication are administered, as are postoperative antibiotics. A general diet is available usually on the evening of surgery. When the patient is able to walk, usually the same day, the urethral catheter is removed. The patient must perform self-catheterization to check urine volume every four hours to protect the urethral wall. If the patient is unwilling to perform catheterization, a tube can be placed suprapubically (in the back of the pubis) for voiding. Catheterization lasts about eight days, with about 98% of patients able to void at three months. Patients are discharged on the second day postoperatively, unless they have had other procedures and need additional recovery time. Patients may not lift heavy objects or engage in strenuous activity for approximately six weeks. Sexual intercourse may be resumed in the fourth week following surgery. Follow-up visits are scheduled for three to four weeks after surgery

Risks
Although the sling treatment has a very high success rate, it is also associated with a prolonged period of voiding difficulties, intraoperative bladder or urethra injury, infections associated with screw or staple points, and rejection of sling material from a donor or erosion of synthetic sling material. Patients should not be encouraged to undergo a sling procedure unless the risk of long-term voiding difficulty and the need for intermittent self-catheterization are understood. Fascial slings seem to be associated with the fewest complications for sling procedure treatment. Synthetic slings have a greater risk of having to be removed due to erosion and inflammation.

Normal results
Regardless of the procedure used, a proportion of patients will remain incontinent. Results vary according to the type of sling procedure used, the type of attachment used for the sling, and the type of material used for the sling. Normal results for the sling procedure overall are recurrent stress incontinence of 3–12% after bladder sling procedures. In general, reported cure rates are lower for second and subsequent surgical procedures. A recent qualitative study published in the American Journal of Obstetrics and Gynecology of 57 patients who underwent patient-contributed fascial sling procedures indicates good success with fascial sling procedures. At a median of 42 months after the procedure, the postoperative objective cure rate for stress urinary incontinence was 97%, with 88% of patients indicating that the sling had improved the quality of their lives. Eighty-four percent of patients indicated that the sling relieved their incontinence long term, and 82% of patients stated that they would undergo the surgery again. The study also found that voiding function was a common side effect in 41% of the patients.

Morbidity and mortality rates
The most common complications of sling procedures are voiding problems (10.4%), new detrusor instability (7–27%), and lower urinary tract damage (3%). Some of the complications depend upon tension issues as well as on the materials used for the sling. There are recent and well-designed studies of patient fascia and donor fascia used for slings in five centers with followup from 30 to 51 months that report no erosions or vaginal wall complications in any patients. Prolonged retention or voiding issues occurred in 2.3% of patients and de novo or spontaneous urge incontinence developed in 6%. These figures relate only to a large study utilizing patient or donor fascia and one that did not control for other factors like techniques of anchoring. In general, studies of the sling procedure are small and have many variables. There are no long term studies (over five years) of this most popular procedure.

Alternatives
Alternatives to anti-incontinent sling procedure surgery depend upon the severity of the incontinence and the type. Severe stress incontinence with intrinsic sphincter deficiency can benefit from bulking agents for the urethra to increase compression, as well as external devices like a pessary that is placed in the vagina and holds up the bladder to prevent leakage. Urethral inserts can be placed in the urethra until it is time to use the bathroom. The patient learns to put the insertion in and take it out as needed. There are also urine seals that are small foam pads inserted in garments. Milder forms of incontinence can benefit from an assessment of medication usage, pelvic muscle exercises, bladder retraining, weight loss, and certain devices that stimulate the muscles around the urethra to strengthen them. For mild urethral mobility, procedures for tacking or stabilizing the urethra at the neck called Needle Neck Suspension, as well as procedures to hold the urethra in place with sutures, like the Burch method, are alternative forms of surgery.