Minimally Invasive Therapy for Urinary Incontinence and Pelvic Organ Prolapse (Current Clinical Urology) 2014th

6. Fascial Slings: Is There Still a Place?

E. Ann Gormley 

(1)

Department of Surgery, Dartmouth-Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, NH 03756, USA

E. Ann Gormley

Email: ann.gormley@hitchcock.org

Abstract

A pubovaginal fascial sling remains a reasonable surgical option for certain patients with stress urinary incontinence. Autologous tissue should be used instead of a synthetic sling if the urethra is fixed, if tension is desired, or when there is a high risk of infection. A fascial sling may be desired by patients in place of a synthetic. The results of fascial slings are reasonable and even when strict criteria for cure are used, the vast majority of patients report satisfaction at follow-up. Fascial slings do have higher risk of voiding dysfunction when compared to other procedures and the rate of recurrent infections, which may be related to voiding dysfunction, is also higher than in other incontinence procedures.

Indications

The gold standard sling, prior to the widespread adoption of the midurethral sling was the pubovaginal rectus fascial sling. The early operative descriptions of fascial slings by Aldridge and Millen in the 1940s describe the rectus fascia being left attached on one or both ends and a strip or two strips of fascia being passed under the urethra and either sutured to the other strip or being brought back through the space of Retzius on the other side and sutured to the underside of the rectus fascia [12]. The fascial sling that is used today was introduced to the urologic community in 1978 by McGuire and Lytton [3]. They used a combined abdominal vaginal approach using rectus fascia. Fascial slings were initially advocated for complicated cases, patients who had failed multiple procedures such as Kelly plications, needle suspensions, or retropubic bladder neck suspensions and for patients with recognized intrinsic sphincter dysfunction (ISD). A number of publications in the last half of the 1990s, including the AUA guidelines for the surgical treatment of female stress urinary incontinence (SUI) in 1997 helped to fuel the use of the fascial sling as the main surgical procedure for virtually all stress incontinent patients [4]. With the advent of synthetic midurethral slings, many urologists, including some who exclusively practice female urology, have never performed a pubovaginal fascial sling.

Today in the era of synthetic slings, there remains a role for the pubovaginal fascial sling. Patients with pure ISD, however one defines that, should be offered a fascial sling or an injectable. Although there are studies that show success of midurethral slings in patients with ISD, one needs to be very cautious in the patient with a fixed urethra since according to Ulmsted’s Integral theory a midurethral synthetic sling should not work without urethral mobility [5].

Synthetics should be avoided in any patients where sling tension might be beneficial, for example, the patient with myelodyplasia and a wide open bladder neck. If the goal of the sling is to close the bladder outlet, then this is better done at the bladder neck with fascia since putting tension on the midurethra with a synthetic may increase the risk of urethral erosion. In a female neurogenic patient undergoing an incontinent or continent catheterizable stoma, who requires a bladder neck closure, a fascial sling at the bladder neck can be utilized. This is advantageous compared to a formal bladder neck closure since the urethra can still be catheterized or scoped if there are problems with the stoma or catheterizable channel.

Synthetics are also avoided where there is a higher risk of infection because of contamination. Examples of this would include the sling placed in a neurogenic patient who is also undergoing a bladder augmentation with bowel or the patient who is having a sling placed concomitantly with excision of a periurethral abscess or repair of a urethral diverticulum. Fascial slings are also the preferred sling material at the time of or following urethral reconstruction.

Patients with urethral mobility may also be offered a fascial sling. The ideal patient for a fascial sling who has urethral mobility is the patient who wishes to avoid a synthetic. This could be the patient who has failed a prior synthetic sling or had a synthetic complication or it may just be a patient who for some reason would prefer that her own tissue be used. As there is more scrutiny of the use of vaginal mesh for prolapse repairs an increasing number of patients are opting not to have any form of synthetic mesh implanted. The age of the patient must also be considered. Although synthetic midurethral slings offer the young woman a much quicker recovery we do not know the very long-term consequences of mesh in the vagina. This is of particular concern when a young woman is undergoing a second mesh sling or if the sling is being placed concomitantly with or following the placement of vaginal mesh for prolapse.

Preoperative counseling should consist of a discussion of the risks and benefits of autologous tissue vs. synthetic grafts, including potential for more abdominal wound discomfort or voiding problems with the use of their own fascia vs. complications of synthetics.

Results

Cure rates for fascial slings have generally been estimated to be in the range of 80–90 % [6]. In the AUA Guideline for the Surgical Management of Female Stress Urinary Incontinence in 2010, efficacy data were available for a variety of types of fascial slings but most of the available studies reviewed describe autologous fascia slings as described in this chapter [7]. In patients only undergoing a sling, the estimated cured/dry rates ranged between 90 % at 12–23 months and 82 % at 48 months or longer. The number of series reviewed where patients underwent a concurrent prolapse treatment were much smaller with far fewer patients but the cured/dry rates were similar and ranged from 85 to 92 %. In the Panel’s meta-analysis of fascial slings alone, the estimated rates of postsurgical urge incontinence were 33 % in patients with preexisting urge incontinence and de novo urge incontinence was noted in 9 % of patients. The estimated rate of retention was 8 %. Complications were infrequent and included urinary tract infection (16 %), bladder injury (4 %), and wound complications (8 %). In those series where patients underwent a sling with a prolapse repair complication rates were similar.

The largest and most rigorous randomized trial involving fascial slings is the Urinary Incontinence Treatment Network’s SISTeR Trial [8]. Using a very strict definition of continence, the SUI-specific treatment success for a sling which included a negative cough and Valsalva stress test, no self-reported stress symptoms and no retreatment for stress incontinence, was 66 % at 24 months. Overall treatment success at 24 months for a sling was 47 %. Both of these were superior to the success rate for a Burch colposuspension. Patient satisfaction with a sling at 24 months was 86 % which was significantly higher than the Burch which was 78 %. The most common complications in the sling group were urinary tract infections. Procedures to improve voiding occurred exclusively in the sling group and were required in 6 % of patients.

Although fascial slings are felt to be durable, there is a fall off in success rate over time. This was shown in an extension of the SISTeR trial (E-SISTeR) where patients who completed the SISTeR trial were followed for a total of 5 years [9]. The criteria for success in this trial was slightly different since patients did not do pad weight tests or undergo stress testing during the follow-up period. The success rate for fascial slings at 2 years was 52 % and 30.8 % at 5 years. The surgical retreatment rate for SUI was 2 %. At 5 years 83 % of all women in the fascial sling group were satisfied as compared to a satisfaction rate of 87 % at 2 years.

Technique

A combined abdominal and vaginal approach is used with the patient in the low lithotomy position. The lower abdomen, perineum, and vagina are prepped and draped to provide access to the lower abdomen and vagina. A Foley catheter is placed in the bladder to drain the bladder and to allow for palpation of the bladder neck. A 6–8 cm long transverse suprapubic incision is made 2–4 cm above the symphysis. The rectus fascia is exposed and incised transversely above the symphysis. The fascia is lifted off the rectus muscle bellies and a strip of fascia measuring 1.5–2 cm by 6–8 cm is harvested. Each end of the strip of fascia is whip stitched with a running 0 nonabsorbable suture and tied down leaving both ends as long as possible.

A weighted vaginal retractor, such as a Schurback, is inserted into the vagina. The anterior vaginal wall at the level of the bladder neck is infiltrated with a dilute vasopressin solution. A 4–5-cm vertical midline incision or an inverted U-shaped incision is made in the vaginal wall from the midurethra to the bladder neck. Using Metzenbaum or Church scissors, the vaginal wall is sharply dissected laterally off of the periurethral fascia which is identified as a glistening white color. Dissection in this plane is relatively bloodless and prevents inadvertent entry into the bladder or urethra. The vaginal wall is dissected laterally on both sides toward the ischium. Once the sling has been prepared, the pubocervical fascia is perforated sharply on either side of the urethra by keeping the scissors parallel to the perineum and aiming for the patient’s ipsilateral shoulder thus gaining entry into the retropubic space. Finger dissection is used to create a tunnel for the sling into the retropubic space toward the rectus muscle bellies.

The retropubic space is entered via a suprapubic approach, by “popping” the index finger through the triangle bounded by the rectus muscle and the inguinal ligament. Retropubic tunnels are developed in continuity with the vaginal dissection by palpating the fingertip of the vaginal operator behind the rectus muscle. Via a vaginal approach the surgeon inserts an index finger into one side of the vaginal incision and up into the retropubic space. A curved clamp, such as a Crawford, is advanced through the retropubic tunnel from above down using the vaginal finger as a guide. The nose of the clamp is kept in constant contact with the posterior surface of the symphysis to avoid entering the bladder. Once the clamp is passed through the retropubic space and out the vaginal incision the clamp is opened and one end of the sling sutures is grasped and pulled retropubically into the abdominal wound. The same procedure is then repeated on the opposite side to draw up the other end of the sling suture into the abdominal wound. The Foley is removed and a cystoscopy is performed to rule out bladder, urethral, or ureteral injury. Bilateral ureteral jets should be seen to insure ureteral patency. If a bladder perforation has occurred, the sling is removed and a new retropubic tunnel is created. With the Crawford clamp in place, a cystoscopy is repeated. Visualization of a clamp in the bladder is very dramatic, whereas it is possible to miss seeing a piece of sling suture peeking through a small hole.

If no perforation is seen, the sling is gently pulled into the retropubic space bilaterally to seat the sling at the bladder neck. The sling is sutured to the periurethral fascia with one or two 3-0 absorbable sutures. The sling sutures are passed through two small stab wounds in the inferior leaf of the rectus fascia. The abdominal fascia is further dissected off of the rectus muscle so that it can be closed without tension and the vaginal wound is closed.

With a Foley catheter in the urethra, the sling tension is adjusted so that gentle traction on the Foley catheter does not result in inferior urethral mobility. The sling is generally tied very loosely so the surgeon can place 2–3 fingers between the fascia and the knot of the sling sutures. The suprapubic wound is closed and a vaginal pack placed. Abdominal pain and wound issues can be minimized by closing the fascia without tension and by meticulous hemostasis which may prevent seroma formation and subsequent wound break down.

An alternative method of obtaining fascia is to use a fascial stripper to harvest fascia lata. Historically this was done through two or three transverse incisions on the lateral thigh and resulted in a very long strip of fascia. The main reason to consider using fascia lata today is in the patient with a large piece of mesh abdominally. In the patient with a hostile abdominal wall, abdominal dissection can be limited by passing the sling sutures using a Stamey or Peyrera type needle. A cystoscopy should be performed with the needle(s) in place.

Postoperative Problems

Urinary retention, which is usually the result of too much tension at the urethrovesical junction, is the greatest concern. Straining to void causes the sling to tighten. The patient must learn to void by relaxing and allowing the detrusor to contract. Clean intermittent catheterization is used until normal voiding occurs. If the patient is unable to resume normal voiding in 4–8 weeks, division of the sling vaginally will often result in resumption of normal emptying. Recurrent stress incontinence is very rare following sling incision.

In patients with mixed incontinence preoperatively, 20–35 % will have persistent urgency incontinence postoperatively. Fortunately most of these patients will respond to antimuscarinic treatment.

Persistent stress incontinence occurs if the sling is not tight enough to sufficiently compress the urethra particularly if there is excessive scarring from previous procedures. Rarely recurrent stress incontinence develops when the sling suture pulls out of the fascia or breaks in the early postoperative period. To prevent this, patients are advised to refrain from lifting for 4–6 weeks.

Urethral erosion with autologous fascial slings is exceedingly rare and in at least one of these cases the sling was inadvertently placed at the midurethra rather than at the bladder neck [10].

Wound problems, including wound seroma and infection, occur rarely but can be particularly problematic in the obese patient. Some patients may develop pain where the sling suture comes through the rectus. If this persists beyond 6 weeks, the sling suture can be removed under local through the prior abdominal incision.

Recurrent urinary tract infections do occur in the postoperative period and may be due to incomplete bladder emptying. Cystoscopy should be performed for persistent infections to insure that there is no sling or suture material in the bladder or urethra.

Conclusion

Ideally patients with SUI should be offered a choice of incontinence procedures and the choices should include a choice of sling material. To date the patient’s own fascia is considered superior to cadaveric or xenograft tissue making it the best option for the patient who wishes to avoid a synthetic. There are also unique clinical situations where autologous tissue may offer an advantage to a synthetic sling including the need for tension on the sling and in cases where infection would be problematic.

References

1.

Aldridge AH. Transplantation of fascia for relief of urinary stress incontinence. Am J Obstet Gynecol. 1942;44:398.

2.

Millin T. Discussion on stress incontinence in micturition. Proc R Soc Med. 1947;40:361.

3.

McGuire EJ, Lytton B. Pubovaginal sling procedures for stress incontinence. J Urol. 1978;119:82.PubMed

4.

Leach GE, Dmochowski RR, Appell RA, et al. Female Stress Urinary Incontinence Clinical Guidelines Panel summary report on surgical management of female stress urinary incontinence. The American Urological Association. J Urol. 1997;158:875.PubMedCrossRef

5.

Petros PE, Ulmsten UI. An integral theory of female urinary incontinence. Experimental and clinical considerations. Acta Obstet Gynecol Scand Suppl. 1990;153:7–31.PubMedCrossRef

6.

Morgan TO, Westney OL, McGuire EJ. Pubovaginal sling: 4-year outcome analysis and quality of life assessment. J Urol. 2000;163:1845–8.PubMedCrossRef

7.

Dmochowski RR, Blaivas JM, Gormley EA, Juma S, Karram MM, Lightner DJ, Luber KM, Rovner ES, Staskin DR, Winters JC. Appell RA; Female Stress Urinary Incontinence Update Panel of the American Urological Association Education and Research, Inc. J Urol. 2010;183:1906–14.PubMedCrossRef

8.

Albo ME, Richter HE, Brubaker L, Norton P, Kraus SR, Zimmern PE, Chai TC, Zyczynski H, Diokno AC, Tennstedt S, Nager C, Lloyd LK, FitzGerald M, Lemack GE, Johnson HW, Leng W, Mallett V, Stoddard AM, Menefee S, Varner RE, Kenton K, Moalli P, Sirls L, Dandreo KJ, Kusek JW, Nyberg LM, Steers W. Urinary Incontinence Treatment Network. Burch colposuspension versus fascial sling to reduce urinary stress incontinence. N Engl J Med. 2007;356:2143–55.PubMedCrossRef

9.

Brubaker L, Richter HE, Norton PA, Albo M, Zyczynski HM, Chai TC, Zimmern P, Kraus S, Sirls L, Kusek JW, Stoddard A, Tennstedt S, Gormley EA. Urinary incontinence treatment network. 5-Year continence rates, satisfaction and adverse events of Burch urethropexy and fascial sling surgery for urinary incontinence. J Urol. 2012;187(4):1324–30.PubMedCentralPubMedCrossRef

10.

Handa VL, Stone A. Erosion of a fascial sling into the urethra. Urology. 1999;54:923.PubMedCrossRef