Autologous Pubovaginal Sling Placement

Brian J. Linder

Introduction

Female stress urinary incontinence is a highly prevalent and bothersome condition that can have a large impact on quality of life. In fact, in the United States, it is estimated that by age 80 years, roughly 13% of women will undergo an anti-incontinence surgery.¹ Of the available surgeries (i.e., urethral slings with various materials and approaches, periurethral bulking agents, retropubic urethropexy) the risks, benefits, and durability of each procedure is variable and shared decision-making with patients regarding treatment selection is crucial.² This chapter reviews the history, indications, surgical techniques, outcomes, and postoperative management strategies for autologous pubovaginal sling placement.

BRIEF HISTORY OF URETHRAL SLING DEVELOPMENT AND TECHNIQUES

The use of autologous material for urethral sling placement was initially described in 1907 with utilization of a sling based on the gracilis muscle.³ Over the ensuing decades, numerous modifications to the procedure have been described.⁴,⁵ In 1978, McGuire and Lytton⁶ described the use of a rectus fascial urethral sling, where the sling was left attached on one side and then tunneled through the rectus muscle, under the urethra, and reattached to the other side of the rectus fascia. Further modification of this technique, to the more contemporary version, was reported in 1988 by Blaivas and Olsson⁷ who described fully detaching the strip of rectus fascia and then perforating the endopelvic fascia for sling placement. Additional modifications regarding intraoperative (e.g., sling tensioning) and postoperative management continue to evolve.⁸,⁹

Further developments for urethral sling placement continued to occur in the late 1990s and beyond. These modifications included use of synthetic materials instead of harvesting autologous tissue and development of the transobturator approach.¹⁰,¹¹ The use of synthetic material avoided morbidity from tissue harvest (e.g., wound infection, hernia), although added the risk of mesh-related complications (e.g., vaginal mesh exposure, dyspareunia, mesh erosion).¹²,¹³ Likewise, the risk of postoperative dysfunctional voiding or urinary retention is lower following synthetic midurethral sling placement than with pubovaginal slings. In part for these reasons, synthetic sling placement has supplanted pubovaginal slings as the most commonly performed anti-incontinence procedure among gynecologists and urologists alike.¹⁴,¹⁵

Although midurethral slings are commonly performed, they have been subject to increased scrutiny by patients, surgeons, and the legal community following U.S. Food and Drug Administration (FDA) notifications regarding the use of transvaginal mesh for managing pelvic organ prolapse.¹⁶ Indeed, in a review of 1% of a legal database for cases related to mesh placement, 63% of cases involved slings for urinary incontinence, 13% mesh for prolapse, and 23% involved both.¹⁷ For a variety of reasons, around the time of the FDA notifications, while synthetic slings remained the most common procedures performed, at some academic centers an increase in autologous sling placements was identified.¹⁸

INDICATIONS FOR PUBOVAGINAL SLING PLACEMENT

Autologous pubovaginal sling placement can be considered in the setting of either primary or reoperative anti-incontinence surgery. Patient-specific comorbidities or preferences may necessitate avoidance of polypropylene mesh sling materials in some cases.

One of the notable uses of autologous slings is in the setting of concomitant urethral reconstructive procedures, where use of polypropylene mesh may impact wound healing and lead to mesh-related complications. For instance, if placing a sling at the time of urethrovaginal fistula repair, urethral diverticulectomy, or excision of a urethral mesh erosion, fascial slings are the mainstay of anti-incontinence therapy. Although not uniformly necessary during urethral diverticulectomy, concomitant placement of a fascial sling may be useful in some cases. Potential scenarios to consider placement of an autologous sling during diverticulectomy include patients with preoperative stress incontinence, larger diverticulum sizes, and those in a proximal urethral location.¹⁹,²⁰ However, it is worth noting that baseline stress incontinence may
resolve in many patients undergoing diverticulectomy and one can consider delayed sling placement as needed.²¹,²²,²³

An additional clinical scenario where the 2017 American Urological Association (AUA)/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (SUFU) guideline on female stress urinary incontinence suggests considering alternatives to synthetic mesh use is in patients at risk for poor wound healing.² Although there is limited direct evidence on predictors of urethral erosion, those with compromised tissue may be at increased risk. Clinical comorbidities that may impact wound healing in this setting include prior pelvic radiation treatment, long-term steroid use, immunosuppression, and significant scarring from prior vaginal surgeries.²

An additional role for pubovaginal sling placement is when urethral obstruction is intended, for instance for a patient with a neurogenic bladder with both urinary retention (necessitating self-catheterization) and outlet incompetence (resulting in stress incontinence). In this setting, a fascial sling can be placed with more tension than a mesh sling, where urethral erosion over time would be a larger concern.

SURGICAL TECHNIQUE FOR PUBOVAGINAL SLING PLACEMENT

An overview of the procedure is shown in Figure 30.1 and a demonstration is available in the accompanying Video 30.1. The patient is typically placed in the dorsolithotomy position with movable stirrups to allow for changes in position during the abdominal (rectus fascial harvest) and vaginal dissections. The abdomen and vagina are prepared and draped to create the sterile field and perioperative antibiotics are given. Unless there is a concomitant urethral reconstruction to be performed or it is uncertain if a sling will be needed, the procedure starts with the graft harvest. This is to prevent ongoing bleeding from the vaginal dissection during the time of graft harvest.

Rectus Fascia Harvest

In most cases, we use rectus fascia as the sling material. For graft harvest a 7- to 8-cm Pfannenstiel incision is made roughly two fingerbreadths above the pubic bone.
The dissection continues with electrocautery through the subcutaneous tissues to the level of the rectus fascia. Once an area of the fascia has been cleared of adipose, two parallel incisions are made in the rectus fascia approximately 2 cm apart. This will correspond to the width of the sling. The underlying muscle is then separated from the fascia. The surgeon places the index finger of their nondominant hand through the two incisions and underneath the fascial strip which allows for countertraction to aid the dissection (Fig. 30.2). The incisions are then carried laterally with slight upward curve toward the anterior superior iliac spine, to avoid the ilioinguinal and iliohypogastric nerves. Care is taken to maintain the 2 cm width of the sling throughout its entire course. The dissection is carried approximately 5 cm laterally to each side, so the final fascial sling is roughly 10 cm in total length.

Prior to transecting the lateral edges of the fascia, a monofilament permanent suture is secured to the fascial fibers (Fig. 30.3). The tail of this suture is left as long as possible and tagged because it will be used later in the procedure to pass the sling from the vaginal dissection to the abdominal dissection. Leaving the fascia attached laterally facilitates placement of these sutures given fixation of the tissue, as opposed to trying to place these on a back table. Likewise, if exposure of the corner of the fascial defect is difficult, a stay suture for fascial closure can be placed prior to freeing the lateral attachments of the sling. Following this, the lateral edge of the sling is transected, and the fascial strip is freed from any remaining attachments to the underlying muscle. This is repeated on the contralateral side. Typically, the midline portion of the sling is freed last because this is where more scar may be encountered in those with prior surgeries, and this is the portion that will rest underneath the urethra. With the fascial strip completely detached, excess subcutaneous adipose tissue is removed from the graft. Following this, it is stored in normal saline until it is ready for placement.

FIGURE 30.2 Initial fascial incisions and dissection for the rectus fascia harvest. The incisions are parallel and 2 cm apart.

FIGURE 30.3 Securing the lateral aspect of the fascial graft with a permanent suture while the graft remains in situ.

The rectus fascial edges are then mobilized slightly from the muscle underneath, if needed, to allow for a tension-free closure. The fascial incision is closed with a running delayed absorbable suture. Of note, for the lateral aspects of the fascial closure, it is important to include all layers of the fascia because they may have separated in the lateral portion of the incision. A local anesthetic is injected to aid in postoperative analgesia. Typically, we use a long-acting liposomal formulation for this. The subcutaneous tissue and skin are left open at this point to allow a space for trocar passage and tensioning the sling later in the procedure.

In patients with significant retropubic scarring, prior to fascial closure, the rectus muscle can be separated in the midline and an extraperitoneal dissection of the retropubic space performed under direct visualization. Here, staying in the space of Retzius, the intended area for sling passage can be cleared sharply. The fascia can be left open until the sutures have been passed from the vagina to the abdomen. Although this is not routinely necessary, this technique can be useful when significant retropubic scarring is anticipated.

Fascia Lata Harvest

The use of fascia lata for the sling material, rather than rectus fascia, may be considered secondary to patient comorbidities, patient or surgeon preference. For instance, in those with multiple prior abdominal surgeries, ventral hernias repairs (especially with mesh use in the abdominal wall), or morbid obesity, this approach may be preferable.

For the graft harvest, the patient is placed in the lateral position, with the leg intended for graft harvest rotated internally at the hip. The anterior and lateral thigh are prepared and draped from the knee to the anterior superior iliac spine. A 3-cm longitudinal incision is made several centimeters above the patella and superior to the iliotibial tract. The incision is made in
the direction of the greater trochanter and dissection carried down to the fascia lata. Once identified, two parallel longitudinal incisions are made 2 cm apart, in the direction of the fascial fibers. A permanent monofilament suture is placed through the end of the fascial strip, similar to what is described above for a rectus fascial harvest. The two parallel incisions are connected to create a free end, and a thin malleable retractor is used to dissect it from the subcutaneous above and muscle below. A fascial stripper then used to extend the fascial incision and divide the fascia proximally to allow for removal. An additional permanent monofilament suture is used to secure the other end of the graft. The wound is then inspected for hemostasis, closed in multiple layers, and a compressive wrapped dressing is placed.²⁴,²⁵

Vaginal Dissection and Sling Placement

In preparation for the vaginal portion of the surgery, a Foley catheter is placed, the bladder drained, and a weighted speculum placed in the posterior vagina. With palpation of the Foley balloon, the bladder neck is identified and marked. A wide Allis clamp is placed immediately inferior to the urethral meatus for traction. Hydrodissection is performed with injectable normal saline at the midurethral, bladder neck, and periurethral tissues.

We typically prefer an inverted U-shaped incision because it gives superior visualization and access to the endopelvic fascia. The incision starts roughly 2 cm below the meatus and is then extended as it progresses laterally to the level of the bladder neck (Fig. 30.4). A wide base to the incision is needed to avoid flap devitalization. Notably, a midline incision could be used either for surgeon preference or patient factors, such as a narrow vaginal introitus. A wide Allis clamp is placed on the cut edge of the inverted U-incision to provide counter traction for the dissection. The surgeon then uses the index finger of their nondominant hand for tension, and the anterior vaginal wall dissection is carried out superficial to the periurethral and pubocervical fascia (Fig. 30.5). Palpation of the Foley balloon confirms the extent of the proximal dissection. The dissection is then carried posterolaterally until the underside of the pubic bone can be palpated. Care is taken to avoid urethral or bladder neck injury during the dissection. This forms the lateral channel along which the sling will lay. Following this dissection, an index finger can be used to palpate the underside of the bone and endopelvic fascia.