Stress Urinary Incontinence Case File

Stress Urinary Incontinence Case File

Eugene C. Toy, MD, Konrad P. Harms, MD, Keith O. Reeves, MD, Cristo Papasakelariou, MD, FACOG

Case 26

A 46-year-old G2P2002 woman complains of leakage of urine with coughing and sneezing that has worsened over the last several years requiring her to use two to three pads per day despite pelvic floor exercises. She complains that this has adversely affected her social life and is seeking treatment for her condition. She also has occasional urgency and frequency but denies leakage of urine associated with the urge to void. She denies any difficulty emptying her bladder. The rest of her medical history is unremarkable with the patient having had two vaginal deliveries without complications and no prior surgeries. A gynecologic examination is performed and the patient is found to have a normal vagina, a small mobile uterus without significant prolapse, and no palpable adnexal masses.

➤ What is the most likely diagnosis?

➤ What further physical examination should be performed?

➤ What further testing should the patient undergo?

➤ What minimally invasive surgical options are available for the treatment of stress urinary incontinence (SUI) with a hypermobile urethra?

ANSWERS TO CASE 26:

Stress Urinary Incontinence

Summary: This is a 46-year-old G2P2002 woman who complains of urinary leakage with activities associated with increased abdominal pressure. She also has urgency and frequency, but this has not been associated with leakage. She has no prior surgeries and an unremarkable history other than two vaginal deliveries.

➤ Most likely diagnosis: Stress urinary incontinence.

➤ Additional physical examination: The urethra should be examined for urethral hypermobility by direct visualization and/or a Q-tip test (placement of a cotton swab into the urethra to judge urethral mobility). Additionally, a supine empty stress test (SEST) may be performed if the patient has voided recently and a post void residual (PVR) should be determined by in-and-out catheterization or bladder ultrasound.

➤ Additional testing: The patient should have a urinalysis to rule out a urinary tract infection that may be worsening her condition. Additionally, the patient should undergo urodynamic testing to further evaluate her lower urinary tract to determine if her leakage is caused by SUI, detrusor overactivity, or both (mixed incontinence).

➤ Treatment for SUI with urethral hypermobility: Mid-urethral slings are an excellent treatment for women who suffer from SUI with urethral hypermobility.

ANALYSIS

Objectives

1. Know the workup for urinary incontinence.
2. Know the indications for different incontinence surgeries.
3. Be familiar with the intra- and postoperative complications of incontinence surgeries.

Considerations

This is a 46-year-old parous woman who has a history of urinary incontinence associated with coughing and sneezing. She has had two prior vaginal deliveries, which are risk factors for this condition. The history is very important to determine if the patient has any “red flags” to indicate a more complicated condition other than pure genuine stress incontinence. These red flags include nocturia, urgency, frequency, dysuria, delay from cough to leakage, or prior urinary incontinence surgery. This patient complains also of urgency and frequency, but these symptoms don’t seem to be related to urinary incontinence; nevertheless, these complaints may indicate a mixed incontinence. Cytometric evaluation would be important to evaluate for the degree of stress versus urge incontinence, since these findings would guide therapy.

APPROACH TO

Stress Urinary Incontinence

DEFINITIONS

DETRUSOR OVERACTIVITY: A urodynamic observation characterized by involuntary detrusor contractions during the filling phase which may be spontaneous or provoked.

MIXED URINARY INCONTINENCE: The complaint of involuntary leakage associated with urgency and also with exertion, effort, sneezing, or coughing.

STRESS URINARY INCONTINENCE: The complaint of involuntary leakage on effort or exertion, or on sneezing or coughing.

URGE URINARY INCONTINENCE: The complaint of involuntary leakage accompanied by or immediately preceded by urgency.1

CLINICAL APPROACH

Multiparous patients who complain of SUI without a history of prior incontinence procedures usually tend to have hypermobile urethras from what is thought to be injury to supportive structures during the birthing process. Women with SUI and hypermobile urethras are excellent candidates for mid-urethral slings whereas those with nonhypermobile urethras may be better suited for treatment by way of intraurethral bulking agents or bladder neck slings. Currently, there are numerous products on the market, and more being introduced every day, with some devices having been studied in more depth than others. The best procedure for the patient is the one that the surgeon is comfortable performing and best suits the patient’s specific problem. When using mid-urethral slings, it has become increasingly clear that the sling material should be made of monofilament polypropylene with interstices sufficiently wide to allow tissue incorporation and penetration of neutrophils to combat infection. Prior to surgery, the patient should be examined by some method of objective testing to further evaluate the patient’s complaint.

DIAGNOSTICS

Typically before an incontinence procedure is performed, the patient undergoes urodynamic testing. This may be as simple as placing a 16-Fr red rubber catheter through the urethral meatus into the bladder and filling the bladder with sterile saline through a 60-mL syringe attached to the catheter with the plunger removed. By filling with gravity, the saline enters more slowly than pushing the fluid with the syringe’s plunger. It also allows the meniscus of the syringe to be observed. A rise in the meniscus indicates a bladder contraction. In this situation, the patient may be better served by multichannel urodynamics to further evaluate the lower urinary tract. As the bladder is filled, the patient’s first sensation and first urge to void may be recorded. Once capacity or 250 to 300 mL is reached, whichever is achieved first, the catheter is removed. The patient is asked to perform Valsalva maneuver and cough several times, and the practitioner should look for leakage that would imply SUI. If leakage is not seen with the patient supine, the patient should be asked to stand upright with stress testing repeated.

The advantage of simple cystometrics is that it is inexpensive and can be performed in a clinic setting without complicated and expensive equipment. However, this technique does not allow the recording of bladder pressures during stress maneuvers to determine the leak point pressure (LPP), which is the abdominal pressure sufficient to overcome the continence mechanism to result in leakage of urine. It is also unable to determine if the leakage seen is caused by a detrusor contraction during the stress maneuvers.

Complex or multichannel urodynamics involves placing one catheter through the urethra into the bladder to measure vesical pressure and another into the rectum or vagina to measure abdominal pressure. These catheters are then connected to a computer that then displays the pressures generated on a computer screen. The detrusor pressure is then calculated by subtracting the abdominal pressure from the vesical pressure. The fill rate can be controlled and usually varies from 50 to 80 mL/min. Needle electrodes can also be placed into the striated urethral sphincter or patch electrodes applied to the perineum to assess the muscle activity of the striated sphincter. LPP testing is performed at different intervals usually starting at 150 mL to evaluate for SUI. Detrusor overactivity is diagnosed by a rise in detrusor pressure signifying an increase in bladder pressure without an increase in abdominal pressure. Leakage during cough or Valsalva without a rise in detrusor pressure indicates SUI. Other tests that may be performed include a urethral pressure profile or maximum urethral closure pressure (MUCP). The MUCP is performed by placing a urethral catheter into the bladder and then slowly removing the catheter. A peak is then generated as the pressure increases as the catheter passes through the continence mechanism with the MUCP being the maximal pressure recorded. This test as well as a low LPP may help identify patients with intrinsic sphincter deficiency (ISD).

TREATMENT

History

In the early 1900s, slings were first placed at the bladder neck to treat SUI.2 In 1942, Aldridge was the first to describe using autologous rectus fascia at the bladder neck.3 This procedure which has been modified by different surgeons is the basis for the modern day bladder neck sling. Placed at the level of the bladder neck and proximal urethra, these slings are tunneled by a variety of techniques behind the pubis through the retropubic space and can be secured to itself, the rectus fascia, the periosteum of the pubis, or by way of bone anchors. Tensioned correctly, the sling gives support and an adequate amount of compression to prevent incontinence while not causing obstruction sufficient to result in voiding dysfunction. After Aldridge in 1949, Marshall described the first retropubic colposuspension for the treatment of SUI. Called the Marshall-Marchetti-Krantz (MMK), this procedure entailed placing sutures into the endopelvic fascia along the bladder neck and into the periosteum.4 By suspending the endopelvic sutures to Cooper ligament instead of the periosteum, the MMK was modified and renamed the Burch colposuspension. Its first results were published in 1968.5 The Burch colposuspension has been one of the most widely used and studied incontinence procedures. Although the bladder neck sling and Burch colposuspension have comprised the majority of incontinence procedures performed since the 1950s, today they have been largely replaced by the mid-urethral slings developed in the 1990s that continue to evolve into less invasive procedures.

Types of Slings

Bladder Neck Slings As the name implies, bladder neck slings are placed at the level of the bladder neck which is located by using the balloon of a Foley catheter. These slings are placed by passing suture down through the retropubic space into an incision at the level of the bladder neck/proximal urethra, anchored into each end of the sling material and passed through the retropubic space in reverse fashion where the suture is then tied anchoring the sling into place. Materials used in bladder neck sling construction can be autologous (ie, rectus facia, fascia lata), allograft (ie, cadaveric fascia, cadaveric dermis), xenograft (ie, porcine dermis, bovine pericardium, submucosal intestine), or synthetic (ie, polypropylene). Some studies have demonstrated autologous slings to be superior to those constructed from allograft material.6 Bladder neck slings are commonly used to treat patients with severe ISD and/or a nonhypermobile urethra, previously failed midurethral sling procedures, and patients with high risk for synthetic mesh extrusion or erosion. In a comparison study between an intraurethral bulking agent and autologous pubovaginal sling in patients with ISD and largely nonhypermobile urethras, the pubovaginal sling had a much greater objective success rate (81% vs 9%, P < .001), thus demonstrating its good efficacy in this cohort of patients that has been historically difficult to treat.7

Complications of bladder neck slings include incidental cystotomy and new-onset urgency. Incomplete emptying and detrusor overactivity may also result from bladder outlet obstruction from a sling tensioned too tightly. This surgical technique has been well studied with proven durability. The downside of this technique is the required suprapubic incision, increased vaginal dissection, and tissue harvesting with autologous slings that increase operative time and risk of morbidity.

Mid-urethral Slings In 1990 Petros and Ulsten published a theory paper where they described both stress and urge symptoms being derived from a common anatomical site, a lax vagina. They proposed that this laxity may derive from the vaginal wall itself or the supporting structures of the vaginal wall which include ligaments, muscles, and connective tissue insertions.8 Based on this theory, the tension-free vaginal tape (TVT) procedure was created to restore urethral support by a tunneled strip of monofilament polypropylene mesh placed at the mid-urethra. The mesh is passed by a trocar that is tunneled from a suburethral incision at the mid-urethral level through the endopelvic fascia and into the retropubic space. It then passes through the layers of the anterior abdominal wall and out through the skin just above the pubis. This was first performed under local anesthesia with a mean operative time of 22 minutes and a cure rate of 84% at 2 years in patients with SUI and urethral hypermobility.9 Some data suggest that in patients with a low MUCP, a nonhypermobile urethra, or both the cure rate may be 60% or significantly lower.10 Other studies have shown better success in patients with ISD.11 Complications of this procedure include voiding dysfunction from 4% to 20% and mesh extrusion reported by some at 3%.12,13 Though rare, bowel injury and vascular injury have been reported.14,15 Cystoscopy is required intraoperatively to rule out an incidental cystotomy during passage of the trocars. Modifications have been made where this type of retropubic mid-urethral sling may be passed through the abdominal wall and downward through the sub-urethral incision. It appears that this surgery is well suited for patients with SUI or mixed urinary incontinence with a hypermobile urethra.

In 2004, DeLorme published results of a modified mid-urethral sling to decrease the risk of cystotomy as well as bowel injury called the transobturator tape (TOT).16 Skin incisions are made at the level of the clitoris where the adductor longus tendon insertion is located at the labial fold. A trocar is then passed through the obturator fossa and out through the suburethral incision at the level of the mid-urethra. A polypropylene mesh is then attached and the trocar is reversed bringing the mesh out through the skin (Figure 26–1). Although cystoscopy is not required by the manufacturers of these products, it is suggested as urethral injury may occur and bladder injury, though rare, has been reported.17 Modifications to this procedure have been made

Figure 26–1. TOT being tensioned with mesh at the level of the mid-urethra and one arm of the sling visible at the level of the clitoris. (Reproduced, with permission, from Schorge JO, Schaffer JI, Halvorson LM, et al. Williams Gynecology. New York: McGraw-Hill, 2008:983.)

allowing the trocar to be passed in the opposite direction from the suburethral incision out through the obturator foramen. In a review comparing the retropubic approach to the transobturator approach, it appeared that the both methods had similar cure rates. The transobturator approach had less risk of voiding difficulties but higher risk of groin/thigh pain, vaginal injuries, and erosion of mesh.18 Some data suggest that the TOT may not be as successful in patients with ISD defined as an LPP less than 60 cm H2O.19 Based on these data, the transobturator sling is safe and effective in treating patients with the diagnosis of SUI or mixed incontinence with urethral hypermobility. From limited reports, a retropubic mid-urethral sling may have better efficacy in patients with a low LPP or MUCP.

Newer slings that pass through the prepubic space and “mini” slings, which pass under the urethra through a single incision and have no point of exit, are now available on the market. However, at this time, data are too limited to comment on their role in the treatment of SUI.

Burch Colposuspension Although the MMK procedure was successful in treating SUI, it had a 5% to 7% rate of osteitis pubis.20 This prompted many surgeons to prefer the Burch colposuspension which used Cooper ligament rather than the periosteum of the pubic bone as the anchor point.5 Although this procedure has been widely used since the 1960s, it has lost popularity since the advent of the more minimally invasive mid-urethral slings. In this procedure, a low transverse abdominal incision is made down to the peritoneum. The retropubic space is then entered by gentle finger dissection until the bladder neck is visualized. Different techniques may be used to clear the perivesical fat to better visualize the endopelvic fascia lateral to the bladder. A wide variety of techniques have been described as far as number of sutures, types of sutures, and suture placement are concerned. It is important to place sutures into the endopelvic fascia at the level of the bladder neck that are then suspended to Cooper ligament and tied without excessive tension (Figure 26–2). This technique may also be performed laparoscopically which requires advanced laparoscopic skills.

Figure 26–2. Burch colposuspension with two sutures placed into the endopelvic fascia at the level of the bladder neck and two sutures just distal along the urethra. All four sutures are suspended to Cooper ligament loosely.(Reproduced,with permission, from Schorge JO, Schaffer JI, Halvorson LM, et al. Williams Gynecology. New York: McGraw-Hill, 2008:979.)

Currently, this procedure is indicated in the treatment of SUI with urethral hypermobility and may best benefit those patients undergoing an open abdominal procedure such as abdominal hysterectomy or sacral colpopexy. The continence rate at 1 year is approximately 85% to 90% and about 70% at 5 years.21 Common complications include bleeding from the venous plexus of the retropubic space or inadvertent placement of suture into the bladder which can be avoided by intraoperative cystoscopy. Postoperative voiding difficulties may last up to 6 months though often resolve. Changes in anatomy may predispose patients to posterior wall defects, and between 12% and 18.5% of patients may have detrusor overactivity. Those who have had prior unsuccessful surgery, particularly with a low MUCP, the elderly, and those with poor tissue from weaker collagen may be at risk for increased failure.20 A National Institutes of Health (NIH)-sponsored trial also has shown the Burch colposuspension to be protective against new-onset SUI in patients undergoing abdominal sacral colpopexy.22

Comparisons

Although data are limited in comparing these different surgical treatments, a few large studies deserve mention. The autologous pubovaginal sling was recently compared to the Burch colposuspension in a prospective, randomized, multicenter NIH-sponsored trial. In this study at 24 months, success for treating SUI was significantly higher in the fascial sling group (66% vs 49%, P < .001) though the procedure was associated with more urinary tract infections, difficulty voiding, and postoperative urge incontinence.23 When comparing the TVT to older procedures with good success such as the Burch colposuspension, one randomized, controlled trial with 5-year follow-up found no statistically significant difference between the groups in terms of a 1-hour pad test. The Burch group had an increase in enterocele and rectocele while the TVT had tape-related complications in 8% of patients.24 Currently, multicenter studies are underway comparing the TOT to the TVT to better understand the differences between these procedures.

Comprehension Questions

26.1 A 34-year-old woman complains of urinary incontinence that is worsening. Which of the following statements regarding treatment of the incontinence is most accurate?

A. Cystometric evaluation is necessary before performing a surgical procedure.

B. The presence of nocturia is consistent with SUI.

C. Mid-urethral sling procedures have been noted to be equivalent to Burch urethropexy procedures in terms of efficacy.

D. Urge incontinence is best treated by urethropexy.

26.2 A cystometric evaluation that is consistent with genuine SUI demonstrates which of the following?

A. Small bladder capacity

B. Detrusor contractions

C. Normal sphincter pressure

D. Residual volume of 200 mL

26.3 In comparing the advantages of a TVT versus a TOT, which of the following statements is most accurate?

A. TOT seems to have more voiding dysfunction than TVT.

B. TOT seems to have a lower rate of cystotomy.

C. TOT is better suited for patients with a hypermobile urethra.

D. TOT is better suited for patients with a lower urethral closure pressure.

ANSWERS

26.1 C. Patients with pure SUI do not usually have nocturia, urge, or urinary frequency. If the history and physical examination are consistent with genuine stress incontinence, a formal cystometric evaluation does not need to be performed prior to surgery. Urge incontinence is treated medically rather than surgically.

26.2 C. Patients with genuine stress incontinence may have normal or somewhat lower urethral sphincter pressures. They usually have normal bladder capacity and no component of urge or dysuria and absence of detrusor contractions.

26.3 B. TOT procedures seem to have a lower rate of voiding dysfunction and lower rate of cystotomy. TVT procedures seem to be better suited for patients with a hypermobile urethra or lower urethral closing pressures.

Clinical Pearls

See Table 1-2 for definition of level of evidence and strength of recommendation

➤ Patients with ISD, especially those as defined by a nonhypermobile urethra, may be best treated by a bladder neck sling (Level B).

➤ Though data are limited, autologous rectus fascial slings may be more efficacious than slings constructed from allograft or xenograft material (Level C).

➤ Mid-urethral slings composed of wide-spaced monofilament polypropylene have lower complications than those composed of multifilament weave (Level B).

➤ The TVT may be more efficacious than the TOT in treating patients with a hypermobile urethra and low LPP or MUCP (Level B).

➤ The TOT appears to have less voiding dysfunction than the TVT and a lower rate of cystotomy (Level B).

➤ The Burch colposuspension is an effective procedure that may be considered in patients already undergoing an abdominal incision who require incontinence surgery for SUI (Level B).

REFERENCES

1. Abrams P, Cardozo L, Fall M, et al. The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Neurourol Urodyn. 2002;21:167-178. 

2. Kobashi KC, Leach GE. Stress urinary incontinence. Curr Opin Urol. 1999;9: 285-290. 

3. Aldridge AH. Transplantation of fascia for relief of urinary stress incontinence. Am J Obstet Gynecol. 1942;44:398-411. 

4. Marshall VF, Marchetti AA, Krantz KE. The correction of stress incontinence by simple vesicourethral suspension. Surg Gynecol Obstet. 1949;88:509-518. 

5. Burch JC. Urethrovesical fixation to Cooper’s ligament for correction of stress incontinence, cystocele, and prolapse. Am J Obstet Gynecol. 1961;81:281-290. 

6. Howden NS, Zyczynski HM, Moalli PA, Sagan ER, Meyn LA, Weber AM. Comparison of autologous rectus fascia and cadaveric fascia in pubovaginal sling outcomes. Am J Obstet Gyecol. 2006;194:1444-1449. 

7. Maher CF, O’Reilly BA, Dwyer PL, Carey MP, Cornish A, Schlutter P. Pubovaginal sling versus transurethral Macroplastique for stress urinary incontinence and intrinsic sphincter deficiency: a prospective randomised controlled trial. BJOG. 2005;112(6):797-801. 

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

9. Ulsten U, Henriksson L, Johnson P, Varhos G. An ambulatory surgical procedure under local anesthesia for treatment of female urinary incontinence. Int Urogynecol J Pelvic Floor Dysfunct. 1996;7(2):81-85. 

10. Clemons JL, LaSala CA. The tension-free vaginal tape in women with a nonhypermobile urethra and low maximum urethral closure pressure. Int Urogynecol J. 2007;18:727-732. 

11. Segal JL, Vassallo BJ, Kleeman SD, Hungler M, Karram MM. The efficacy of the tension-free vaginal tape in the treatment of five subtypes of stress urinary incontinence. Int Urogynecol J. 2006;17:120-124. 

12. Salin A, Conquy S, Elie C, et al. Identification of risk factors for voiding dysfunction following TVT placement. Eur Urol. 2007;52(3):782-787. 

13. Giri SK, Sil D, Narasimhulu G, Flood HD, Skehan M, Drumm J. Management of vaginal extrusion after tension-free vaginal tape procedure for urodynamic stress incontinence. Urology. 2007;69:1077-1080. 

14. Kobashi KC, Govier FE. Perioperative complications: the first 140 polypropylene pubovaginal slings. J Urol. 2003;170(5):1918-1921. 

15. Sivanesan K, Abdel-fattah M, Ghani R. External iliac artery injury during insertion of tension-free vaginal tape: a case report and literature review. Int Urogynecol J. 2007;18:1105-1108. 

16. Delorme E, Droupy S, de Tayrac R, Delmas V. Transobturator tape(Uratape): a new minimally-invasive procedure to treat female urinary incontinence. Eur Urol. 2004;45:203-207. 

17. Smith PP, Appell RA. Transobturator tape, bladder perforation, and paravaginal defect: a case report. Int Urogynecol J. 2007;18(1):99-101. 

18. Latthe PM, Foon R, Toozs-Hobson P. Transobturator and retropubic tape procedures in stress urinary incontinence: a systemic review and meta-analysis of effectiveness and complications. BJOG. 2007;114(5):522-531. 

19. O’Conner RC, Nanigian DK, Lyon MB, Ellison LM, Bales GT, Stone AR. Early outcomes of mid-urethral slings for female stress urinary incontinence stratified by Valsalva leak point pressure. Neurourol Urodyn. 2006;25(7):685-688. 

20. Bidmead J, Cardozo L. Retropubic urethropexy (Burch colposuspension). Int Urogynecol J. 2001;12:262-265. 

21. Lapitan MC, Cody DJ, Grant AM. Open retropubic colposuspension for urinary incontinence in women. Cochrane Database Syst Rev. 2003;1:CD002912. 

22. Brubaker L, Cundiff GW, Fine P, et al. Abdominal sacrocolpopexy with Burch colposuspension to reduce urinary stress incontinence. N Engl J Med. 2006;354(15): 1557-1566. 

23. Albo ME, Richter HE, Brubaker L, et al. Burch colposuspension versus fascial sling to reduce stress urinary incontinence. N Engl J Med. 2007;355(21):2143-2155. 

24. Ward KL, Hilton P, on behalf of the UK and Ireland TVT Trial Group. Tension-free vaginal tape versus colposuspension for primary urodynamic stress incontinence: 5-year follow up. BJOG. 2008;115:226-233.

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