Primary Stress Urinary Incontinence: What to Do and Why

Abstract

Stress urinary incontinence (SUI) is defined as the involuntary leakage of urine on effort, exertion, sneezing, or coughing. SUI is the most common cause of urinary incontinence in younger women and the second most common cause in older women. Surgery offers high cure rates and is considered by many to be the first-line therapy for uncomplicated SUI in women. Currently, a variety of surgical procedures are available to treat symptomatic SUI. This article reviews the process of choosing a primary surgical procedure for women with SUI.

Stress urinary incontinence (SUI) is defined as the involuntary leakage of urine on effort, exertion, sneezing, or coughing. Urodynamic SUI is defined as the involuntary leakage of urine during filling cystometry associated with increased intra-abdominal pressure in the absence of a detrusor contraction. ¹ SUI is the most common cause of urinary incontinence in younger women and the second most common cause in older women.² Surgery offers high cure rates and is considered by many to be first-line therapy for uncomplicated SUI in women.^3,4 Currently, a variety of surgical procedures is available to treat symptomatic SUI. This article reviews the process of choosing a primary surgical procedure for women with SUI.

Clinical Assessment

The process of choosing a primary surgical procedure begins with a thorough clinical assessment. The accurate diagnosis of SUI is made by a combination of history and physical examination, which includes visualizing leakage of urine from the urethra during a cough stress test or during urodynamic studies. A systematic examination of vaginal support should also be performed because SUI and pelvic floor disorders often coexist. The routine use of multichannel urodynamics in the preoperative assessment of women with uncomplicated clinical SUI remains extremely controversial.^2,5–8 The American College of Obstetricians and Gynecologists (ACOG) recommends the use of urodynamic testing to confirm the diagnosis when surgery for SUI is planned, unless the history and physical examination are uncomplicated and consistent with the diagnosis.⁵ Similarly, the International Consultation on Incontinence (ICI) recommends performing urodynamic testing in the following 3 clinical situations:⁸

• When voiding dysfunction or neuropathy is suspected,

• When an invasive surgical procedure is planned,

• When there has been failure of a prior surgical procedure.

Considerable debate continues to surround the value and cost-effectiveness of the routine use of urodynamics as part of routine surgical planning for uncomplicated SUI.

The introduction of minimally invasive surgical options has revolutionized the treatment of SUI. Although conservative therapies such as behavioral modification, pelvic floor muscle exercises, incontinence devices, and medications exist, their widespread use has been precluded by their inconvenience, cost, side-effect profiles, and variable efficacy. Surgery offers higher cure rates than behavioral therapies and bulking agents, and is thus considered to be first-line therapy for uncomplicated SUI in women who desire definitive management. The following discussion focuses on women who desire surgical management.

Surgical Management

Several factors influence the selection of a primary surgical procedure for women with symptomatic SUI. Surgeons must weigh the probability of a successful outcome against the possibility of failure or complications and adverse events. Reviewing patient goals and discussing expectations can optimize patient and surgeon satisfaction with treatment.^9,10 Initial factors involved with choosing a primary surgical procedure for the treatment of SUI include:

• Coexistence of treatable pelvic organ prolapse,

• Medical comorbidities and the functional status of the patient,

• Experience and technical skills of the surgeon.

Selection of a Surgical Procedure

The first consideration is whether the surgical approach will be influenced by the route used for repairing coexisting pelvic organ prolapse (Figure 1). There are 2 surgical approaches: (1) vaginal (including midurethral sling, bladder neck sling, and injectable urethral bulking agents) and (2) abdominal-open, laparoscopic, and robotic (including Burch colposuspension).

Figure 1.

Treatment algorithm for choosing a primary surgical procedure for women with stress urinary incontinence. Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © 2002–2010. All Rights Reserved.

Uncomplicated SUI

In women with uncomplicated SUI without pelvic organ prolapse, the most commonly performed surgical procedures are midurethral slings, retropubic colposuspensions, and injections of urethral bulking agents. The use of urethral injectable agents is usually limited to medically compromised and elderly women who are unable to tolerate surgery. In addition, they have been used for recurrent or refractory incontinence in patients who failed a previous incontinence procedure.

Preferences in surgical technique have shifted over the last decade from predominantly retropubic colposuspensions and bladder neck slings to more minimally invasive midurethral slings. As a result, there are more data on midurethral slings than on any other female incontinence procedure. A recent Cochrane review concluded that midurethral slings should be considered the gold standard for the primary surgical treatment of uncomplicated SUI without prolapse.^3,4,11 Their widespread adoption is attributed to a shorter operating time, low morbidity, less voiding dysfunction, and quicker recovery compared with open retropubic procedures.

Once the decision has been made to proceed with a midurethral sling, there are a few items to consider. Midurethral slings are performed using a vaginal approach with the passage of trocars through either the retropubic or transobturator spaces (Figure 2). In a recent randomized trial of 170 women comparing the retropubic transvaginal tape (TVT) to transobturator tape (TOT) for the primary treatment of urodynamic SUI, the TOT was found to be equally efficacious as the TVT.¹² A systematic review of 17 trials that included 2434 women demonstrated that a retropubic approach was associated with higher objective cure rates than a transobturator approach (88% vs 83%, respectively; relative risk [RR], 0.96; 95% confidence interval [CI], 0.93–0.99), although subjective cure rates were similar. The studies used a variety of measures to define objective cure rates including urodynamic studies, cough stress tests, and pad tests. Subjective cure rates were based on symptoms or information gathered from questionnaires. The transobturator approach, however, was associated with significantly less blood loss, fewer bladder perforations, less de novo urgency, and less voiding dysfunction.¹¹

Figure 2.

Mid-urethral slings are performed using a vaginal approach with the passage of trocars through either the (A) retropubic or (B) transobturator spaces. Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © 2002–2010. All Rights Reserved.

Some studies suggest that there are certain urodynamic parameters associated with increased success rates.¹³ A low maximum urethral closure pressure and abdominal leak point pressure have been associated with an increased risk of failure in transobturator slings as compared with retropubic slings.^14,15 Intrinsic sphincteric deficiency (ISD), defined as a maximal urethral closure pressure below 20 cm H₂O or a Valsalva leak-point pressure less than 60 cm H₂O, have been associated with an increased risk of failure with the transobturator approach. In a randomized, controlled trial comparing the TVT to the TOT for the treatment of 164 women with urodynamic SUI and ISD, urodynamic SUI was persistent in 14 of 67 subjects (21%) in the TVT group compared with 32 of 71 subjects (45%) in the TOT group (P = .004) 6 months following surgery. Nine patients in the TOT group requested a repeat surgical procedure, compared with none in the TVT group.¹⁶ Information on certain urodynamic parameters may be useful in selecting a retropubic versus a transobturator sling.

The long-term effectiveness of TVTs was demonstrated in 2 prospective cohort studies. Nilsson and colleagues reported a 90% cure rate, as evidenced by a negative cough stress test and 24-hour pad test, 11.5 years following surgery.¹⁷ Similarly, Liapis and colleagues reported an 80% cure rate defined as a negative urodynamic stress test and pad test 7 years after surgery.¹⁸

Midurethral slings also appear to be effective treatment options for both obese and elderly women. One observational study reported no difference in outcomes following a TVT in obese (body mass index [BMI] > 40 kg/m²) compared with nonobese women (BMI < 30 kg/m²).¹⁹ The postoperative outcome measure was a negative cough stress test. Furthermore, in a study comparing women older than 70 years to women younger than 70 years, both groups had significant improvements in their quality of life following surgery.²⁰

SUI With Symptomatic Pelvic Organ Prolapse

In women with SUI and symptomatic pelvic organ prolapse, the choice of surgical procedure to treat the incontinence is often dictated by the surgical route used to repair the prolapse. The merit of a vaginal versus abdominal approach for the treatment of pelvic organ prolapse remains a topic of debate among experts. At this time, there are insufficient high-quality data to guide surgeons toward one surgical approach. Operative planning should continue to be individualized to the anatomic location of the prolapse, the surgeon’s skill and experience, and the patient’s medical comorbidities and preferences.

The efficacy of TVTs appears similar to open Burch colposuspension. In a large, multicenter, randomized trial comparing TVT with Burch colposuspension, the postoperative results based on a 1-hour pad test and a cough stress test were similar between the 2 groups 6 months after surgery (66% and 57%, respectively; P = .099). Bladder perforation was significantly more common in the TVT group, whereas operative time, return to normal voiding function, and resumption of normal activities were significantly longer in the Burch colposuspension group.²¹ Data from the same trial reported 5 years after surgery remained similar between the 2 groups, demonstrating a lack of superiority of one procedure over the other for the primary surgical treatment of SUI.²²

The Burch colposuspension often accompanies an abdominal sacrocolpopexy. In a systematic review of 46 clinical trials including 4738 women, the open Burch colposuspension was noted to have overall cure rates ranging from 68.9% to 88%. Specifically, within the first year cure rates were approximately 85% to 90% and dropped to approximately 70% after 5 years.²³

The prophylactic use of the Burch colposuspension to reduce the risk of postoperative SUI in women with advanced prolapse without SUI was addressed by the Colpopexy and Urinary Reduction Efforts (CARE) trial.²⁴ In this multicenter trial, 322 women were randomized to undergo sacrocolpopexy with or without a Burch colposuspension. The trial was terminated early due to a significant difference in incontinence rates at 3 months following surgery. The addition of a Burch colposuspension significantly reduced the risk of SUI at 3 months (RR, 1.85; 95% CI, 1.32–2.6).²⁵ Twenty-four months after surgery the prevalence of SUI was significantly lower in the Burch versus no Burch group (32% and 45%, respectively; P = .026).²⁶

With the advent of minimally invasive surgical techniques, the Burch colposuspension can also be performed laparoscopically. In a systematic review of laparoscopic Burch colposuspensions, 10 studies were identified that compared laparoscopic to open Burch procedures. Objective cure rates, defined as a negative cough stress test, were similar between the 2 approaches 18 months to 5 years following surgery (RR, 1.01; 95% CI, 0.88–1.16).²⁷ In a randomized trial of 200 women comparing laparoscopic to open Burch colposuspension, objective cure rates, defined as the absence of urodynamic SUI, were similar between the 2 groups at 6 months.²⁸ A second randomized clinical trial revealed similar findings at 24 months with no difference in 1-hour pad tests. The objective cure rates for laparoscopic and open procedures were 79.7% and 70.1%, respectively.²⁹ Laparoscopic Burch colposuspension requires significant experience and technical skill, limiting its routine use.

SUI With Asymptomatic Pelvic Organ Prolapse

There is a paucity of data on the role of combined surgical treatment of symptomatic SUI and asymptomatic prolapse. The surgeon and patient are often faced with the dilemma of repairing the asymptomatic prolapse at the time of the incontinence surgery. Many surgeons will repair the prolapse if the patient has obesity or increased parity, which have been associated with increasing progression of prolapse. In a single retrospective study of Medicare insurance claims, women who had concomitant prolapse repair at the time of their sling were significantly less likely to undergo a second procedure for prolapse within 1 year.³⁰ However, the retrospective nature of the study precluded a systematic ascertainment of stage of prolapse and symptoms. Because the natural progression of prolapse remains poorly defined among asymptomatic women with some studies noting spontaneous regression, it remains unclear whether asymptomatic prolapse should be repaired in women undergoing surgery for symptomatic SUI.^31–34 It is important to counsel patients regarding all surgical options, allowing them to make informed decisions.

Procedures No Longer Recommended

Long-term studies comparing the Burch colposuspension, modified Pereyra needle procedure, and anterior colporrhaphy with Kelly plication for the treatment of primary SUI revealed success rates of 82% for Burch colposuspension, 43% for modified Pereyra needle procedure, and 37% for anterior colporrhaphy with Kelly plication 5 years after surgery.^4,35 Therefore, transvaginal needle suspension procedures, anterior colporrhaphy, and paravaginal repairs are no longer recommended as a primary treatment of SUI.⁴ In addition, recent guidelines no longer recommend the use of Marshall-Marchetti-Krantz, a type of retropubic procedure, for the primary treatment of SUI.⁴

Women With SUI and Planning Future Pregnancy

Because pelvic support may be disrupted during pregnancy and following a vaginal birth, most physicians recommend delaying surgical management of SUI until child-bearing has been completed. A survey of current members of the American Urogynecology Society (AUGS) revealed that 40% would recommend an elective cesarean delivery in patients with a prior incontinence surgery, whereas only 28% would be comfortable with a trial of labor.³⁶ Case reports suggest that continence is maintained in the short term following a vaginal delivery; therefore, women of child-bearing age should not be precluded from having surgery but should be extensively counseled on the lack of data on the long-term efficacy of the original incontinence procedure and the potential need for a future cesarean delivery.^37,38

Main Points.

• Stress urinary incontinence (SUI) is defined as the involuntary leakage of urine on effort or exertion or on sneezing or coughing.

• Surgery offers high cure rates for uncomplicated SUI. Accurate diagnosis is paramount to ensure optimal patient outcomes.

• Midurethral slings are considered first-line therapy for uncomplicated SUI without pelvic organ prolapse.

• Transobturator (TOTs) and retropubic (TVTs) slings have comparable efficacy; however, TOTs are associated with fewer bladder perforations, less blood loss, and a lower risk of postoperative voiding dysfunction.

• Open and laparoscopic Burch procedures have similar cure rates, whereas open Burch procedures have similar cure rates to TVTs.

• Anterior colporrhaphy, transvaginal needle suspension procedures, and Marshall-Marchetti-Krantz are no longer recommended for the primary treatment of SUI.