Surgery Insight: Management of Failed Sling Surgery for Female Stress Urinary Incontinence

Craig V Comiter

Disclosures

Nat Clin Pract Urol. 2006;3(12):666-674. 

In This Article

Sling-related Complications

Extrusion and Erosion

Sling-related complications vary with the material composition of the sling. While surgery with prepackaged synthetic slings is associated with a quicker recovery, shorter operating time, shorter hospital stay, and lower rate of urinary retention compared with autologous rectus fascial slings, synthetic slings are associated with vaginal extrusion and urethral erosion rates that are 10 times higher than the rates for organic slings.[14]

Urethral erosion (Figure 1) is likely to result from placement of the sling deep in the periurethral fascia, too close to the urethral spongy tissue or mucosa, or from excessive tension in the sling causing ischemic necrosis. Intraoperative cystourethroscopy is always indicated to rule out urethral or bladder perforation, whether the sling is placed through a retropubic or a transobturator approach.

Figure 1.

Eroded urethral sling in a patient who presented with recurrent urinary tract infections. The sling was placed deep to periurethral fascia, and is completely incorporated into the urethra (arrow). Partial excision of the urethra was necessary. The periurethral fascia should be reapproximated over the urethra to minimize the risk of fistulization.

Over the past 5 years, polypropylene has emerged as the most widely used sling material. Cadaveric fascia[15] and porcine xenografts[16] tend to be less durable and are associated with less predictable clinical outcomes than synthetic slings. PTFE (Polytetrafluoroethylene), silicone and polyester slings lead to unacceptably high rates of vaginal extrusion and urethral erosion, typically greater than 5%.[17,18,19] Polypropylene, on the other hand, has many of the desirable characteristics of a sling material; it is durable, noninflammatory, and conducive to tissue ingrowth.[5]

With monofilament woven polypropylene slings, vaginal extrusion or urethral erosion occurs at a rate of approximately 1%[20] in most contemporary series. Other synthetics, such as PTFE (Gore-Tex® [WL Gore & Associates, Inc, Newark, DE]), polyester (Dacron® [Invista North America SARL, Wilmington, DE] or Protegen), or silicone (InteMesh® [AMS, Minnetonka, MN]) have higher erosion and extrusion rates, ranging from 4% to 30%.[21,22]

Several factors contribute to the wide range of erosion and extrusion rates, including operative technique, the size of the implant, and specific properties of the sling material such as pore size, stiffness, elasticity, and basic tissue compatibility. Placement of the sling in a plane too close to the urethra, or the presence of inadequate vaginal tissue coverage, poor vaginal tissue vascularity, or bacterial infection secondary to a draining hematoma or seeding of the mesh can lead to early sling erosion or extrusion. Basic incompatibility between the sling and the host may lead to more-delayed erosion or extrusion, well after the usual time for complete wound healing. Solid and excessively woven materials are associated with a higher complication rate than meshed slings,[23,24] most probably because of the smaller or absent pores. Attaching the sling to a mobile structure such as the rectus sheath (as opposed to the fixed pubic bone) can also inhibit tissue ingrowth by permitting movement and chronic irritation, leading to sinus formation and erosion.[24] Similarly, a stiff graft might not conform and coapt to the surrounding host tissue, further interfering with tissue ingrowth.

Newer, synthetic slings with narrower widths and numerous interstices such as TVT (tension-free vaginal tape [Ethicon®; Johnson & Johnson, New Brunswick, NJ]) and SPARC® (AMS, Minnetonka, MN) have become quite popular; however, they are not free from the risk of urethral erosion and vaginal extrusion.[25,26] Although most erosions and extrusions from TVT and SPARC® procedures are reported as small series or case reports, such complications seem to be quite rare, despite more than 600,000 cases performed worldwide. The low rates of urethral erosion and vaginal extrusion are likely to be caused by the favorable characteristics of the loosely woven polypropylene tape. A loose fiber weave with pores >80 μm in diameter theoretically permits the passage of macrophages and tissue ingrowth, thereby allowing integration of the graft into the surrounding tissues.[26]

Management of Erosion

Management of urethral erosion depends on the sling material used. With synthetic sling erosion, complete removal of the sling and any permanent suture material is necessary, but bone anchor removal is not necessary unless the patient has osteomyelitis. The urethral defect should be closed over a catheter, and the periurethral fascia should be reapproximated with placement of a labial fat graft if the repair is tenuous. In such instances, the urethral catheter should remain in place for 2 weeks. The likelihood of postoperative incontinence in patients ranges from 44% to 83%.[27,28] Simultaneous salvage anti-incontinence surgery should be undertaken with caution, as the risk of recurrent urethral erosion is particularly high. Furthermore, care should be taken to inspect for bladder erosion, which often demonstrates encrustation (Figure 2). If the sling material is incorporated into the bladder wall and cannot be easily removed, partial cystectomy with total excision of the foreign material may be necessary.

Figure 2.

Lateral bladder wall with sling inadvertently placed intravesically. The patient complained of dysuria, bleeding, and urgency. Note the encrustation.

While erosion with organic slings is 15 times less likely to occur than with synthetic materials, such complications do occur. In patients with organic sling erosion, incision or partial excision of the sling, a multilayer urethral closure is usually sufficient to correct the problem.[29]

Bone Anchors

It is unclear if the use of bone anchors during transvaginal surgery is associated with an elevated risk of bony complications. The group from the Cedars Sinai Medical Center reports an incidence of osteitis pubis of 0.45% and no cases of osteomyelitis with the use of transvaginal bone anchors in 440 patients.[30] Other reports from centers of excellence include one from the Northwestern University group, with an incidence of osteitis of 0.4% and an incidence of osteomyelitis of 1.3% in patients having bone anchors placed at the time of sling surgery.[31] A group from the Cleveland Clinic reported that osteomyelitis and osteitis pubis occurred in patients receiving bone anchors at the time of sling surgery at rates of less than 1%.[32]

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....