Anterior Vaginal Wall Sling

The Raz anterior vaginal wall sling is a relatively new surgical procedure developed since 1992 at the University of California Los Angeles Medical Center. It creates a sling for the treatment of intrinsic sphincter dysfunction (ISD) or anatomic (hypermobility-related) incontinence without burying vaginal epithelium or using autologous fascial strips. Permanent sutures are placed into the periurethral supporting tissues to create a hammock of support from the naturally occurring anatomic structures adjacent to the bladder neck and urethra. To achieve improvement in continence status, two main surgical goals must be met: (a) provide support and increased coaptation to the urethra and (b) create a strong hammock of vaginal wall and underlying tissues to provide a backboard of support to the midurethra and bladder neck during times of increased intra-abdominal pressure.

DIAGNOSIS

The presence of stress urinary incontinence should be confirmed objectively by the surgeon with physical examination, cystoscopy, and urodynamics. Epidemiologic studies have shown that 1% of patients who complain objectively of stress urinary incontinence actually have an alternative diagnosis such as profuse vaginal discharge or endocervical cysts, which may mimic incontinence. If incontinence can not be demonstrated objectively by the routine evaluation, then a pyridium pad test may be helpful in confirming the diagnosis. Before surgery, administration of a self-directed incontinence-specific quality-of-life score such as the Raz Quality-of-Life Score, the Incontinence Impact Questionnaire, or the Urogenital Distress Inventory will help to quantify the degree of clinical significance urinary incontinence is having on an individual patient.

Once incontinence is demonstrated, it is classified as intrinsic sphincteric dysfunction (ISD) or anatomic incontinence (AI). Because no pathognomonic test exists for ISD, the diagnosis is made by a combination of historical, physical, and urodynamic parameters. Factors typically associated with ISD include multiple prior surgeries, prior radiation exposure, direct urethral trauma, or neurologic dysfunction. The abdominal leak-point pressure is typically low. In contrast, patients with AI have hypermobility of the bladder neck and urethra, and the abdominal leak-point pressure is found to be higher than that in those with ISD. In addition to those patients who fit classically into either the ISD or AI categories, there exists a group of patients who may exhibit characteristics of both etiologies with an abdominal leak-point pressure in the gray zone between these two categories. Although patients with a broad range of intra-abdominal leak-point pressures have been treated with the anterior vaginal wall sling, we still continue to classify patients as ISD or AI types to aid in preoperative counseling. Patients with ISD may take longer to resolve postoperative urinary retention and have a lower incidence of resolution of preoperative instability symptoms than do patients with AI.

INDICATIONS FOR SURGERY

This procedure is indicated for clinically significant female stress urinary incontinence secondary to bladder neck hypermobility or intrinsic sphincter dysfunction with little (grade 1) or no cystocele. Like any vaginal surgery, it is contraindicated in patients who can not adequately be placed in lithotomy position because of physical restrictions such as limited hip abduction. Modifications of this procedure can be made to treat incontinence associated with grade 2 or 3 cystocele (six-corner suspension). Grade 4 cystocele requires a more extensive procedure in which both central and lateral defects are corrected.

ALTERNATIVE THERAPY

In contrast to the Raz vaginal wall sling, which uses permanent sutures placed in the periurethral supporting tissues, a sling can be created from a variety of alternative materials. These can be classified as endogenous sources (fascia lata, rectus fascia, or harvested strips of anterior vaginal wall) or exogenous sources. The latter are either synthetics such as Marlex mesh or natural sources such as banked human dura. In addition to sling procedures, ISD may be treated surgically with injectable agents (collagen, fat, Teflon, silicon) or the artificial urinary sphincter.

Alternative surgical treatments for anatomic or hypermobility-related incontinence are classified by the surgical approach—either abdominal, such as the Burch suspension, or vaginal, such as the Gittes or Stamey procedure. The Raz bladder neck suspension, which was previously used to treat anatomic incontinence, has now been replaced by the anterior vaginal wall sling at our institution.

SURGICAL TECHNIQUE

Preparation

In preparation for surgery, the patient should be given an oral stool softener to begin on the day before surgery. Broad-spectrum intravenous antibiotics such as an aminoglycoside plus a cephalosporin or a broad-spectrum DNA gyrase inhibitor are administered preoperatively.

Following general or spinal anesthesia, the patient is placed in the lithotomy position with the buttocks just overhanging the edge of the operating table. This will allow the weighted vaginal speculum to hang freely without contact against the operating table. The feet should be adequately padded in protective boots and placed in leg-supporting stirrups. If the patient is obese, slight Trendelenburg positioning of the table will help to expose the suprapubic region. The skin is then painted with an iodine-based solution from the level of the umbilicus inferiorly to include the whole perineum. The vagina is also painted with an iodine-based solution. A speculum or long forceps should be used to aid in the skin preparation of the vagina to ensure that the entire vagina is adequately prepared to avoid bacterial contamination of the suture material. The drapes are placed to expose the suprapubic region and perineum, with the anus carefully excluded from the field. Several 3-0 silk sutures are used to anchor the drape covering the anus to ensure that it does not fall away during the procedure, thereby contaminating the field.

To obtain maximum exposure, the 30-degree weighted vaginal speculum is placed in the vagina, following which single 3-0 silk labial retraction sutures are placed into the labia minora. Appropriate placement of these two retraction sutures will greatly aid in the exposure. Be sure they anchor the labia both laterally and superiorly to exposure the urethra and bladder neck region of the anterior vaginal wall. Always apply retraction sutures after the vaginal speculum is in place to avoid unnecessary tension or suture pull-out.

Suprapubic Cystostomy

A 14-Fr Foley catheter is used for suprapubic drainage. To place the suprapubic catheter, the closed curved Lowsley forcep is placed into the bladder by the surgeon and pressed against the anterior vaginal wall 2 cm above the symphysis pubis in the midline. The assistant feels for the tip of the forceps and makes a puncture wound with the scalpel blade cutting the skin and rectus fascia. The operator pushes the tip of the forceps through the wound, and the assistant positions the 14-Fr Foley catheter into the jaws of the retractor. Do not lubricate the tip of the catheter or curved Lowsley retractor to ensure that the catheter does not slip out of the jaws of the retractor. Withdrawal of the retractor by the surgeon delivers the tip of the catheter out the urethra. A small forceps is used to hold the tip of the catheter inside the bladder while the assistant inflates the balloon with 10 cc of water and irrigates with 50 cc of normal saline to ensure correct positioning within the bladder. The suprapubic catheter is placed on traction, and the bladder is emptied with the suction and clamped off. A second 14-Fr Foley catheter with 10 cc of water in the balloon is placed per urethra and clamped off. Palpation of the balloon against the bladder neck is helpful in identifying this landmark vaginally. The assistant places three Allis clamps at the level of the midurethra (midway between the bladder neck and external meatus) on the anterior vaginal wall and retracts upward, exposing the anterior vaginal wall for the surgeon.

Anterior Vaginal Wall Sling

Before the vaginal incisions are made, 10 cc of saline is injected just beneath the vaginal wall along the anticipated suture lines to facilitate dissection. Two oblique incisions are made in the anterior vaginal wall, extending from the level of the midurethra to 2 cm below the bladder neck. Dissection is carried out laterally using the Metzenbaum scissors to expose the vaginal side of the urethropelvic ligament bilaterally. This dissection should be superficial. Deep dissection with perforation of the ligament can result in excess bleeding. The attachment of the urethropelvic ligament to the tendinous arc can be felt by the operator by placing a finger into the incision pointing toward the ipsilateral shoulder of the patient. With gentle pressure, the curved Mayo scissors are placed into each wound against the tendinous arc and advanced until the retropubic space is entered. Opening the blades of the scissors helps to detach the urethropelvic ligament from the tendinous arc. The operator can now place a finger into the wound and feel the open retropubic space. Blunt finger dissection is used to detach any adhesions within the retropubic space from both sides. The space should feel freely open with the finger, and one should be able to palpate the urethra easily in the midline.

Two pairs of #1 Proline suture on a half-circle tapered MO-5 needle are used to complete the sling. As each suture is passed to the surgeon, its free end is held with a small mosquito forceps, which can rest on the patient’s abdomen while the surgeon completes suture placement. This keeps the free end of the suture well within the sterile field and prevents potential contamination.

Begin with placement of the proximal pair of Proline sutures, which are similar to those used in the traditional Raz bladder neck suspension. A long forceps is placed into the retropubic space, and the urethra and bladder are retracted medially. A #1 Proline suture is placed in a helical fashion into the urethropelvic ligament, taking several passes. Then, with the needle kept parallel to the plane of the vagina, the suture is passed in the vaginal wall (excluding the epithelium) to incorporate a large surface area of the underlying vesicopelvic fascia. A similar procedure is carried out on the contralateral side.

To place the second, more distal pair of Proline sutures, the long forceps is placed into the open retropubic space. Opening the jaws of the forceps parallel to the floor and retracting inferiorly will create an open triangle in the retropubic space. At the apex of this triangle is the levator muscle as it inserts into the pubic symphysis and the midurethral segment. The urethropelvic ligament in the medial vaginal wall forms the lateral border of the triangle. The floor of the triangle is parallel to the cardinal ligaments.

Using a #1 Proline suture, incorporate several passes of the levator muscle and the edge of the urethropelvic ligament. In order to obtain an adequate amount of levator tissue, the needle must be placed deep into the retropubic space. The levator should be visualized on the arc of the needle. Reposition the forceps to put downward traction on the anterior vaginal wall in the area of the midurethra and incorporate several helical bites of the underlying periurethral fascia incorporating tissue up to but not crossing the midline. As in placing sutures into the vesicopelvic fascia it is important to keep the needle parallel with the vaginal wall to prevent suture material from entering the spongy tissue of the urethra itself. After all four Proline sutures are in place, one can visualize a rectangle of support for the bladder neck and midurethra.

A clean blade is used to make a puncture wound the width of the double-pronged needle carrier in the midline, just above the superior margin of the pubic bone. If the incision is made too high, the sutures will be transferred over a mobile area of the anterior abdominal fascia, which can result in pain or incomplete support. The incision is carried down to, but not through, the rectus fascia. With a finger in the retropubic space serving as a guide, the double-pronged needle carrier is advanced through the suprapubic incision, the retropubic space, and out through the vaginal incision. As the needle passes into the retropubic space, it should hug the symphysis in the midline to ensure that the needle passes into the thick and less mobile area of the rectus fascia. The freed ends of one of the ipsilateral Proline sutures is placed through the needle holes in the double-pronged ligature carrier. Retraction of the needle carrier delivers both ends of the suture out through the suprapubic incision. A total of four passes are made, each suture being transferred individually. Do not attempt to transfer more than one suture at a time—this can result in tangling or knotting of the Proline sutures.

Indigo carmine is injected intravenously, and cystoscopy is performed with 30- and 70-degree lenses. This ensures that (a) the suprapubic tube is in good position, (b) blue efflux is noted from both ureteral orifices, (c) no Proline suture material has entered the bladder, and (d) upward retraction on the suprapubic Proline sutures provides support to the bladder neck and midurethra.

The urethral catheter is replaced, and the assistant provides upward retraction with the three Allis clamps, once again exposing the anterior vaginal wall. The two oblique incisions are closed with a running, locking absorbable suture of 2-0 polyglycolic acid on a tapered UR-5 needle. The shape of this needle allows better placement of sutures high in the vagina. A vaginal pack laden with antibiotic cream is inserted into the vagina, following which the weighted vaginal speculum is removed. Last, the Proline sutures are tied independently to their ipsilateral mates over the rectus fascia, creating the hammock of support . Excessive tension in the suspending sutures may lead to prolonged pain and is not necessary to achieve support. The skin edges of the suprapubic wound are freed, and the Proline knots are buried. Failure to adequately free the skin edges can result in dimpling of the skin over the Proline knots, which can cause patient discomfort. The suprapubic skin wound is closed with intradermic 4-0 absorbable sutures and Steri-strips.

Within 24 hours the vaginal pack and urethral catheter are removed. The suprapubic catheter is plugged, and the patient begins to record her voided volumes and the postvoid residual. The patient is discharged with an oral stool softener, an oral antibiotic, and analgesics. When the residual urine is consistently low, the suprapubic catheter is removed in the office.

OUTCOMES

Complications

The majority are preventable by (a) proper positioning of the patient, (b) careful dissection and identification of the important anatomic landmarks, and (c) routine performance of intraoperative cystoscopy for early identification and correction of potential problems. Patients at increased risk for complications include those with a history of prior bladder or pelvic surgery, endometriosis, pelvic infection, pelvic fracture, or significant pelvic prolapse. These factors may alter the typical pelvic anatomy. Although a detailed review of female pelvic anatomy is beyond the scope of this chapter, several excellent resources are available.

Intraoperatively, minor bleeding most commonly results from dissection in the wrong fascial plane, such as perforation of the urethropelvic ligament rather than dissection over its glistening surface during exposure. Bleeding may also occur following opening of the retropubic space if entrance is made too close to the urethra with subsequent injury to the periurethral vessels. Temporary placement of a pack into the retropubic space will facilitate exposure and provide hemostasis until a suture ligature can be applied. Temporary packing is always preferable to the excessive use of electrocautery on the delicate tissues of the urethra and bladder. Rarely, arterial vessels are found within the vaginal wall and are encountered shortly after the vaginal wall incisions are made. Should this occur, an Allis clamp placed over the edge of the vaginal wall will secure hemostasis until a suture ligature is applied. Postoperatively, vaginal spotting of blood may be noticed by the patient within the first two postoperative weeks. If vaginal bleeding continues or is increasing, perform a vaginal examination and place a temporary vaginal pack.

Misplaced Proline sutures occur when the anatomic landmarks are not clearly exposed and identified. This can potentially result in ureteral or bladder perforation or injury. Both of these complications may be diagnosed with the use of intraoperative indigo carmine and careful cystoscopy. If suture material is identified within the bladder, immediately remove the offending suture and ensure that the ureters are intact, performing retrograde pyelograms if necessary. Ureteral injuries may require stenting for minor injuries or reimplantation for complete ligations. Perforation of the bladder during dissection is exceedingly rare and should be repaired immediately intraoperatively by a multiple layered vaginal closure adhering to the principles of vesicovaginal fistula repair.

P>Postoperative suprapubic pain may be related to suspension sutures and is often activity related, subsiding with several weeks of decreased physical activity. It is often idiopathic in nature but may also be caused by cellulitis, subcutaneous abscess formation, muscle entrapment, vigorous overtying of sutures, or placement of sutures through a mobile portion of the anterior abdominal wall. Transferring of sutures in such a site may create tension over the rectus muscle during activity. Passing the double-pronged needle in the midline, as close to the pubic bone as possible, and not tying sutures under tension will minimize this complication.

Vaginal stenosis or shortening may result from excessive plication of the vaginal epithelium during closure or secondary scarring. When the vaginal wall is closed, the running suture is locked to aid in the prevention of excessive plication of the tissue. A history of new onset of dyspareunia or pelvic or vaginal pain and the finding of foreshortening on physical examination confirm the diagnosis. Mild shortening or stenosis may be treated with longitudinal relaxing incisions in the lateral vaginal wall with transverse closure.

Voiding dysfunction in the early postoperative period is common following surgery for stress urinary incontinence. Before surgery, the patient should be informed of common potential changes in her voiding pattern, including temporary retention and mild bladder irritability. The majority of patients with the new onset of voiding dysfunction have resolution of their symptoms within a short period of time; however, persistent voiding dysfunction should be reevaluated with physical examination, cystoscopy, and videourodynamics.

Urinary retention in the immediate postoperative period resolves in the majority of patients with the use of a suprapubic catheter or intermittent self-catheterization. Permanent retention has not been reported as a complication of this procedure.

Persistent or recurrent stress incontinence requires complete urodynamic evaluation and usually reoperation if it is of a severity to affect the patient’s quality of life. In this case, reoperation with proper suture placement should correct the problem. When the cause is recurrent intrinsic sphincteric dysfunction, alternative corrective measures including injection of urethral bulking agents or artificial urinary sphincters may be considered.

Pain, redness, and swelling in the suprapubic area should alert the surgeon to a potential infection at the site of suspension suture knots, which may require drainage should antibiotic therapy be unsuccessful. Lower urinary tract infections are common in the first month following any vaginal surgery and generally respond to a short course of oral antibiotics.

Results

In 1995 the clinical outcome of the sling procedure was reported in 163 women ranging in age from 31 to 81 years. The cohort was followed prospectively with a median follow-up of 17 months (range 6 to 32 months). Three patients were lost to follow-up. Of the 160, 95 had intrinsic sphincter dysfunction (ISD), and 65 anatomic incontinence (AI). One hundred fifty-two patients were considered cured of stress urinary incontinence at last follow-up. Eleven of 163 patients were considered failures and had recurrent incontinence that was unrelated to bladder instability and required further therapy. Time to recurrent stress incontinence comparing ISD and AI patients, as modeled using Kaplan–Meier survival curves and the log-rank test, showed no significant difference between patients with preoperative anatomic incontinence and those with intrinsic sphincter dysfunction (p > 0.05). Conditional logistic regression covariates revealed no significant predictive factors for postoperative failures. Seven percent of patients developed de novo instability. Pre- and postoperative within-patient changes of quality-of-life scores were found to be statistically significantly improved for both AI and ISD patients.

These initial results indicate that excellent continence was achieved in patients with both ISD and AI using the anterior vaginal wall sling. Advantages of this technique include the absence of a laparotomy incision, short hospital stay, lateral placement of permanent nonreactive sutures, and the ability to correct mild cystocele. The procedure has been shown to be safe and effective and allows for outpatient surgical management of bothintrinsic sphincter dysfunction and anatomic incontinence.

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