Functional: Female SUI

See 2023 AUA Female SUI Guideline Notes

Definitions

• Stress Urinary Incontinence (SUI): symptom of urinary leakage due to increased abdominal pressure, which can be caused by activities such as sneezing, coughing, exercise, lifting, and position change.
• Intrinsic sphincter deficiency (ISD): often defined as an abdominal leak point pressure <60 cm H20 or a maximal urethral closure pressure <20 cm H20, often in the face of minimal urethral mobility
  • The utility of urethral function assessment remains controversial
• Urgency urinary incontinence (UUI): symptom of urinary leakage that occurs in conjunction with the feeling of urgency and a sudden desire to urinate that cannot be deferred.
• Mixed urinary incontinence refers to a combination of SUI and UUI

Epidemiology

• Prevalence of female SUI: up to 49%

Pathogenesis

• Early theories regarding the cause of SUI were focused on the unequal transmission of pressure to the bladder and urethra, urethral hypermobility, and the abnormal inferior location of the urethra.
• Later theories (integral theory) emphasized the importance of 3 separate components that support the proximal and midurethra:
  1. Pubourethral ligaments
  2. Suburethral vaginal hammock
  3. Pubococcygeus muscle
  • Injury to any of these components from surgery, parturition, aging, or hormonal deprivation can lead to impaired midurethral function and subsequently SUI
• Intrinsic sphincter deficiency (ISD) is the primary underlying cause of SUI for women, with hypermobility being a secondary finding i.e. all women with SUI have some component of ISD, not all have hypermobility
  • Urethral hypermobility is a symptom of damage to the normal supporting structures of the urethra and not a cause of SUI
  • Maximum urethral closure pressures (MUCPs) < 20 cm H2O or abdominal leak point pressure (ALPP) < 60 cm H2O are indicative of ISD
    • In women who are continent, MUCP occurs at the midurethra
    • ALPP > 90 cm H2O signifies no or very little ISD

Differential Diagnosis of SUI

• Options (7)
  1. Overflow incontinence
  2. Detrusor overactivity incontinence
  3. Low bladder compliance
  4. Stress-induced detrusor overactivity
  5. Diverticulum
  6. Urinary fistula
  7. Ectopic ureter

Diagnosis and Evaluation of Patients Wanting Surgery for SUI

Recommended Investigations

Mandatory (4):

1. History (including assessment of bother) and Physical Exam
2. Objective demonstration of stress urinary incontinence
3. Urinalysis
4. PVR

History and Physical Exam

History

• Characterize incontinence (stress, urgency, mixed, continuous, without sensory awareness)
  • Presence of coughing, sneezing, lifting, walking, or running as initiators of incontinence increases the likelihood of SUI as the cause of urinary leakage
  • Chronicity of symptoms
  • Frequency, bother, and severity of incontinence episodes. Pad or protection use.
    • An assessment of bother is paramount to the decision to operate in the index patient.
• Associated
  • Urinary tract symptoms (e.g., urgency, frequency, nocturia, dysuria, hematuria, slow flow, hesitancy, incomplete emptying)
  • Pelvic symptoms (e.g., pelvic pain, pressure, bulging, dyspareunia)
  • GI symptoms (e.g., constipation, diarrhea, splinting to defecate)
• Menopausal status
• Obstetric history (e.g., gravity, parity, method of delivery)
• Previous pelvic surgeries
• Past medical history (e.g., hypertension, diabetes, history of pelvic radiation)
• Current and past medications
• Fluid, alcohol, and caffeine intake
• Previous treatments for incontinence (e.g., behavioral therapy, Kegel exercises/pelvic floor muscle training, pharmacotherapy, surgery)
• Patient’s expectations of treatment (patient-centered goals)
• History alone, while helpful, does not definitively diagnose SUI in women

Physical exam (6):

1. Stress test (supine and/or standing) with comfortably full bladder
2. Focused abdominal examination
3. Urethral mobility (Q-tip test or other method)
4. Pelvic prolapse (any method)
5. Vaginal atrophy/estrogenization status
6. Focused neurologic examination

Objective demonstration of SUI

• Stress test (supine and/or standing) with comfortably full bladder
  • Considered positive if involuntary urine loss from the urethral meatus is witnessed coincident with increased abdominal pressure
    • A positive stress test had a high sensitivity and specificity for detecting SUI
  • If leakage is not witnessed in the supine position, the test may be repeated in the standing position to facilitate the diagnosis

Urinalysis

• Screen for abnormalities (microscopic hematuria, pyuria, etc.), which may prompt further investigations and reveal underlying cause (bladder tumour, for example) of incontinence

Post-void Residual (PVR)

• May prompt further investigations and reveal underlying cause (overflow, for example) of incontinence

Other Tests

Questionnaires

• Overall, low strength of evidence due to limited number of studies for each questionnaire

Q-tip test

• Positive test is unlikely to aid in the diagnosis of SUI; SUI may exist without urethral hypermobility and vice versa.
• Can provide potentially useful information regarding the degree of urethral mobility

Pad test

• May confirm the presence of incontinence but does not distinguish the specific type

Additional Evaluations

• Should be considered for patients with the following conditions (8):
  1. Neurogenic lower urinary tract dysfunction (known or suspected)
  2. Inability to demonstrate stress urinary incontinence
  3. Inability to make definitive diagnosis based on symptoms and initial evaluation
  4. Elevated post-void residual per clinician judgment
  5. Evidence of significant voiding dysfunction
  6. Urgency-predominant mixed urinary incontinence
  7. Abnormal urinalysis, such as unexplained hematuria or pyuria
  8. High grade pelvic organ prolapse (POP-Q stage 3 or higher) if SUI not demonstrated by pelvic organ prolapse reduction
• May be performed in patients with:**Concomitant overactive bladder symptoms
  • Failure of prior anti-incontinence surgery
  • Prior pelvic prolapse surgery

Cystoscopy

• Should not be performed in index patients for the evaluation of SUI
• Indications (3):
  1. Suspected bladder pathology based on history or concerning findings on physical exam or urinalysis (e.g. microhematuria)
  2. Structural lower urinary tract abnormality
  3. Patients undergoing certain surgical procedures (e.g., midurethral (MUS) or pubovaginal fascial (PVS) slings) to confirm the integrity of the lower urinary tract and the absence of foreign body
  4. History of prior anti-incontinence surgery or pelvic floor reconstruction, particularly if mesh or suture perforation is suspected
     • Perforation should be suspected with new onset of lower urinary tract symptoms, hematuria, or recurrent UTI

UDS

• May be omitted for the index patient desiring treatment when SUI is clearly demonstrated
  • VALUE (NEJM 2012)
    • Population: 630 females with uncomplicated SUI
    • Randomized to preoperative office evaluation and urodynamic tests vs. evaluation only
    • Primary outcome: Treatment success at 12 months, defined as a reduction in the score on the Urogenital Distress Inventory of 70% or more and a response of “much better” or “very much better” on the Patient Global Impression of Improvement
    • Results: preoperative office evaluation alone was not inferior to evaluation with urodynamic testing
    • Nager, Charles W., et al. "A randomized trial of urodynamic testing before stress-incontinence surgery." New England Journal of Medicine 366.21 (2012): 1987-1997.
• May be performed at the urologist’s discretion in certain non-index patients, including but not limited to (8):
  1. Neurogenic lower urinary tract dysfunction
  2. Unconfirmed SUI
  3. Mismatch between subjective and objective measures
  4. Elevated PVR per clinician judgment
  5. Significant voiding dysfunction
  6. Significant urgency, UUI, overactive bladder (OAB)
  7. History of prior pelvic organ prolapse surgery
  8. History of prior anti-incontinence surgery
• If significant prolapse is present, UDS should be performed with and without a pessary
• In patients with DO, treatment options other than sling surgery should be considered because stress-induced DO may be difficult to treat with a sling alone.
• Abnormally small bladder capacity and decreased compliance may also negatively affect the outcomes of sling surgery, and these factors should also be considered.

Management

Options

• Observation
• Non-surgical interventions (4):
  1. Urethral plugs
  2. Vaginal inserts
  3. Continence pessary
  4. Pelvic floor muscle training (± biofeedback)
• Surgical intervention
  • Options (4):
    1. Periurethral bulking agents
    2. Midurethral sling (MUS)
    3. Autologous pubovaginal sling (PVS)
    4. Burch culposuspension
• Physicians should not offer stem cell therapy for SUI outside of investigative protocols

Observation

Indications (2)

1. Patient expresses minimal subjective bother due to the SUI
   • The degree of bother should be considered when considering treatment
2. Not candidate for other forms of therapy

Non-surgical interventions

• Options (4):

1. Urethral plugs
2. Vaginal inserts
3. Continence pessary
4. Pelvic floor muscle training (± biofeedback)

Pelvic floor physical therapy

• Patient must be willing and able to commit to regularly and consistently performing pelvic floor training for this to be successful.

Surgical intervention

• In most cases of incontinence, surgery should not be considered until more conservative management has failed.

• Options (4):

1. Bulking agents
2. Synthetic midurethral slings (MUS)
3. Autologous pubovaginal sling (PVS)
4. Burch culposuspension

Bulking agents

• Trade name: Bulkamid
  • FDA approved in 2020§
• Little long-term data
• Indications (2):
  1. Patients who wish to avoid more invasive surgical management or are concerned with the lengthier recovery time after surgery
  2. Patients who experience insufficient improvement following a previous anti-incontinence procedure.
• Disadvantage (1)
  1. Patients should be counseled on the expected need for repeat injections
• Adverse events§
  • Pain at implantation (13%)
  • Acute urinary retention (6%)
  • Urinary tract infection (4%)
  • Blood in urine (2%)

Midurethral Slings (MUS)

• Most studied surgical treatment for female SUI
• Other than bulking agents, MUS is also the least invasive surgical options to treat SUI

Classification (3):

1. Retropubic MUS (RMUS, e.g. TVT-R); top-down or bottom-up
2. Transobturator MUS (TMUS e.g. TVT-O); inside-out or outside-in
   • TVT without specification refers to TVT-R
3. Single incision sling (SIS)/adjustable sling types

• Retropubic vs. Trans-obturator synthetic midurethral sling
  • Efficacy
    • Short-term analyses found them to be equivalent
    • Long-term comparisons are relatively lacking, however, data from increasing follow up appear to be demonstrating a lack of durability of Transobturator MUS, compared to Retropubic MUS
• Mechanics of the Midurethral Sling
  • MUS works by impeding the movement of the posterior urethral wall above the sling, directing its motion in an anteroinferior or anterior direction. In addition, inward movement of the posterior urethral wall after placement of a MUS results in urethral lumen narrowing (compression).
  • Ideally placed loosely at the midurethra
  • Overall, patients without urethral hypermobility do not respond as well to MUS surgery.
    • Lack of urethral mobility is an indication that the patient has a fixed urethra and ISD.
  • A loosely placed MUS combined with a mobile urethra may allow the sling to compress the urethra during times of Valsalva and stress while remaining nonobstructive when the urethra is at rest.
    • Unlike retropubic and transobturator MUSs, for single-incision MUSs it appears that restriction of urethral mobility after surgery is associated with a better outcome
• Anatomy
  • Anatomy of the Retropubic Midurethral Sling
    • The left and right dorsal nerves of the clitoris (DNCs) run along the inferior surface of the ischiopubic rami and cross under the pubic bone approximately 1.4 cm from the midline
    • The obturator vessels are the closest major vascular structures to a retropubic MUS
  • Anatomy of the Transobturator Midurethral Sling
    • The transobturator technique is unique because (when done correctly) it avoids entry into the true pelvis and the levator group.
      • Muscle’s traversed by this technique include the obturator internus muscle, obturator membrane, and obturator externus muscle as it goes through the obturator foramen, and the adductor muscles (adductor magnus, adductor brevis, and gracilis), lateral to the obturator foramen
        • Errant sling placement through the adductor longus tendon can result in substantial pain.
    • The obturator vessels are lateral and superior to the area of insertion of the device.
    • The dorsal nerve of the clitoris is separated from the trajectory of the device by ≥1-2 cm
• Midurethral Sling Materials
  • The initial MUSs were made of materials with smaller pore sizes
  • Currently, a soft, loosely woven, polypropylene monofilament mesh with a pore size > 75 μm is the most commonly used material
• Midurethral Sling Operative Procedures
  • Patient Counseling
    • Because MUS surgery involves the implantation of a synthetic, prosthetic material, surgeons should thoroughly counsel their patients about the permanent nature of these products and the unique and sometimes serious complications related to their use. Also, similar to the PVS, patients should also be counseled about the risk of transient and permanent voiding dysfunction after surgery. This should include a discussion of postoperative difficulty emptying the bladder and de novo urgency and frequency.
  • Technique
    • In general, a MUS should be placed loosely at the midurethra because its function is not primarily related to compression.
      • For single-incision MUSs, tension should be tighter than the classic retropubic or transobturator MUS surgeries to achieve the same result
    • Cystoscopy is performed to exclude trocar penetration of the lower urinary tract.
    • If bladder perforation is noted, the trocar is withdrawn and passed once more with an effort to avoid further perforation.
• Outcomes of MUS for
  • Predominantly SUI
    • Outcomes of transobturator MUS procedures in patients with predominantly SUI are similar to those of the retropubic MUS, regardless of urethral function
    • 5-year results demonstrate durability similar to 1-year results
    • Single-Incision MUS in Patients with Predominantly SUI
      • There are fewer data available regarding the safety and efficacy of this new generation of slings compared with the retropubic and transobturator MUSs.
      • Single-incision slings have decreasing efficacy with longer follow-up.
  • MUI
    • Results with mixed incontinence are acceptable compared with other types of interventions for urinary incontinence but are less than those obtained in pure SUI.
  • Intrinsic Sphincteric Deficiency
    • The success of MUSs is lower in patients with ISD/fixed urethra (no urethral mobility) and low leak point pressures
      • Fixed urethras have poor outcomes after MUS surgery regardless of leak point pressure
      • Retropubic MUS are more effective than transobturator MUS in patients with ISD
    • Low leak point pressures are not necessarily a contraindication to retropubic MUS surgery
    • MUS is beneficial in the management of SUI in patients with ISD as long as there is preoperative urethral mobility; urethral mobility before MUS procedures has been shown to be predictive of success; the more the proximal urethra moves during a Valsalva maneuver, the better the cure rate for incontinence
  • Pelvic Organ Prolapse
    • Results suggest that the MUS can be added to prolapse surgery with minimal morbidity.
      • The Cochrane Incontinence Group reviewed 22 randomized trials of surgical prolapse repair including 2368 women. They concluded that the addition of a retropubic MUS to endopelvic fascial plication, Burch colposuspension, and abdominal sacrocolpopexy may reduce the incidence of postoperative SUI, but issues of cost and associated adverse effects were unclear
      • Women who underwent prolapse repair at the time of the sling surgery were significantly more likely to be diagnosed with postoperative outlet obstruction (9.4% vs. 5.5%, P < .007), but less likely to undergo a repeat procedure for stress incontinence or reoperation for prolapse within 1 year after sling surgery.
      • When MUSs are placed for urodynamic or occult SUI at time of prolapse repair, the risk of intervention because of obstruction is equivalent to the risk of intervention for SUI if no MUS was placed (8.5% and 8.3%, respectively)
    • MUSs placed with either transvaginal or laparoscopic-assisted vaginal hysterectomy and anterior or posterior colporrhaphy have been shown to have success rates similar to those in published series of MUS surgery alone. Complication rates are also in accordance with other MUS series
  • Elderly Patients
    • Cure rates in older women with urethral hypermobility are comparable to those in younger women.
      • Elderly women should not be excluded from potentially curative MUS surgery based on their age alone.
      • Mixed urinary incontinence resolution rates are similar to those of the younger population
      • Possibly because of preoperative factors such as MUI or even decreased urethral hypermobility, the rate of persistent SUI after retropubic or transobturator MUS procedures appears higher in the elderly population [different than above?].
    • Complication rates vary, with some studies citing a higher rate of age-related morbidities but no apparent increase in intraoperative complications.
      • Elderly patients experience higher rates of postoperative de novo urgency and urgency incontinence associated with any sling material, including MUS
      • Postoperative retention occurs to a similar degree as in younger patients
  • Obese Patients
    • Whether obesity affects surgical outcome with MUSs is controversial.
    • Overall, the rate of complications appears to be similar in obese versus non-obese patients undergoing MUS surgery.
      • Higher rate of bladder trocar injury in non-obese patients
  • Efficacy and safety of MUSs are not compromised in the elderly, the obese, or those undergoing concomitant vaginal surgery.
  • Recurrent Stress Urinary Incontinence
    • As salvage procedures, MUS have overall efficacy similar to their use in primary implantation procedures.
    • The procedure can be performed in the same way as it is performed for primary SUI.
    • The complication rate is similar to that of retropubic MUSs done for primary SUI, but the risk of bladder perforation appears to be higher in females who have had ≥1 prior retropubic suspensions.
    • As is the case with primary surgery, the failure rate is higher in females with immobile urethras.
    • No significant difference in subjective cure rates in patients after retropubic vs. transobturator MUS surgery for recurrent SUI.

Adverse events

• Overall, relatively low rates of complications
  1. Bladder trocar injury: 2.7-3.8%; higher with retropubic
  2. Voiding dysfunction: 7.6%
  3. Wound healing problems: 1%
  4. Vaginal mesh exposure: 0.5-8.1%
  5. Mesh perforation of urethra (transobturator and retropubic): 0-0.6%
  6. Mesh perforation of bladder: 0.5-0.6%
  7. Sexual dysfunction
  8. Groin pain; higher with transobturator; conservative therapy with NSAIDs should resolve the majority of symptoms. If pain persists after 6-8 weeks, consider referral to a pain clinic for trigger point injections and physical therapy.
  9. Bleeding, vascular injury; higher with retropubic
  10. Infection, bowel perforation, and death
• Patient, technical, and sling factors contribute to risk of adverse events
  • Trend in the contemporary literature toward the use of macroporous polypropylene slings
    • The increased pore size of these materials allows for: excellent tissue ingrowth, promotes integration with the surrounding host tissues, and decreases encapsulation and infection
• MUS Bladder Trocar Injury
  • Rate of trocar injury is higher with retropubic vs. trans-obturator MUS
    • The rate of bladder or urethral trocar injury:
      • Retropubic MUS surgery: 2.7-23.8%
      • Trans-obturator MUS surgery: 0-1.3%
  • Trocar injury is generally thought of as a benign condition. If occurs intra-operatively, remove trocar and pass trocar again more laterally and leave foley catheter in 3-7 days.
• MUS Vaginal Mesh Exposure
  • Most cases manifest within a few weeks to a few months after the MUS procedure
  • Diagnosis and Evaluation
    • Symptoms of vaginal mesh exposure include:
      1. Vaginal discharge (with variable constituents and different amounts of blood and inflammatory components)
      2. Palpable rough surface in the vagina
      3. Sexual discomfort (including partner related)
      4. Pelvic pain
      5. Inguinal discomfort
      6. LUTS (urgency, frequency, persistent incontinence, hematuria)
  • Management
    • The management of this complication is not standardized, composition of mesh is particularly important in the event of mesh exposure
    • Conservative management is an option in well-selected patients who are relatively asymptomatic and have small-caliber exposures (<1 cm)
    • The next step involves addition of conjugated estrogen and possibly antibiotic creams
    • Excision should be reserved for failure of conservative therapy or when local symptoms mitigate against observational management (e.g., bothersome dyspareunia). Limited excision and trimming with vaginal closure can be attempted. Even with partial excision of the mesh, continence is maintained in the majority of patients.
    • If these options fail, excision of most of the mesh from a transvaginal approach should be pursued in most cases.
      • Operative management typically involves excision of the exposed mesh, thorough irrigation with antibiotic solution, and closure of vaginal flaps. Good results have also been observed in selected patients with vaginal advancement flaps and suture approximation of the debrided vaginal mucosa over the exposed mesh.
• MUS Mesh Perforation of the Urethra
  • Diagnosis and Evaluation
    • History and Physical Exam
      • History
        • Presenting symptoms are variable
        • Voiding dysfunction is predominant
  • Management
    • Management of this complication is extremely challenging
    • Observation should never be considered when there is urethral perforation
    • Options (2)
      1. Endoscopic management of small areas of mesh perforation
      2. Transvaginal surgical excision
         • For slings that perforate into the urethra an inverted-U incision is best because this allows for exposure of the proximal urethra, bladder neck, and endopelvic fascia as well as providing a vaginal epithelial flap that avoids overlapping suture lines
         • An autologous fascial sling or a Martius labial fat pad graft can be used, at the discretion of the surgeon.
         • An autologous fascial sling can be placed at the time of surgery to augment the repair or in a delayed fashion to treat recurrent SUI.
• MUS Mesh Perforation of the Bladder
  • Pathogenesis
    • Most likely the result of an unrecognized cystotomy or placement of the mesh within the urinary bladder at the time of surgery.
  • Diagnosis and Evaluation
    • History and Physical Exam
      • History
        • Typical symptoms are lower abdominal pain, intermittent gross hematuria, recurrent UTI, urgency, frequency, dysuria, and urinary incontinence
  • Management
    • Observation should never be considered when there is intravesical perforation
    • Options
      1. Endoscopic management (excision with scissors or ablation with the holmium laser) is an appropriate initial step for small areas of mesh perforation although this is contingent on absolute excision of all exposed material
      2. After endoscopic excision fails or as an initial treatment, mesh perforated into the bladder can be removed from a transvaginal or retropubic approach.
         1. Reconstruction should involve nonoverlapping suture lines and interposition of tissue such as a labial fat pad or greater omentum.
         2. An autologous fascial sling can be placed at the time of surgery to augment the repair or in a delayed fashion to treat recurrent SUI.
• Pain and Infection after MUS Surgery
  • Groin and suprapubic pain are potential problems after MUS placement. Thigh and groin pain appear to be more commonly associated with the transobturator approach
    • Most groin pain resolves after the second postoperative day.
      • Pain persists longer after the transobturator midurethral slings.
  • Severe infection is a rare complication after MUS surgery, and the diagnosis of this complication is variable and can take as long as several years
    • Obesity, diabetes, and hypertension are associated with fasciitis after pelvic surgery.
  • Management of MUS Severe Infection or Pain.
    • In most cases, postoperative groin or leg pain after MUS surgery can be managed with NSAIDs, rest, and physical therapy. Most groin pain resolves after postoperative day 2
    • In instances of chronic mesh pain and severe infection when nonoperative therapy has failed, it may be necessary to attempt a complete mesh excision from both sides of the bone.
    • For the complete excision of transobturator mesh we typically consult an orthopedic surgeon to aid with lateral dissection of the sling.
• Voiding Dysfunction after MUS Surgery
  • Voiding dysfunction after MUS is substantially less than with PVS (bladder neck) slings but still occurs
  • Usually transient, long-term urinary retention and obstructive voiding dysfunction are rare after the MUS procedure
  • Typically the result of obstruction from the sling as a consequence of the sling being placed too tightly or in the wrong location (too proximally) or associated with pelvic organ prolapse (unrecognized preoperatively or de novo); however, some patients may have voiding dysfunction without evidence of obstruction
  • In general, the rates of de novo urgency and perioperative urinary retention are similar among the different types of MUSs. The most common symptoms of obstruction are an inability to void (urinary retention), incomplete emptying, and de novo urgency and frequency. Over several weeks to a month, the irritative voiding symptoms (urgency, frequency, and pain) become more prevalent as the bladder attempts to adjust to the obstruction.
    • De novo urgency occurs with postoperative voiding dysfunction in as many as 12% of patients
    • However, a recent RCT found significantly higher rate of voiding dysfunction necessitating surgery (or permanent catheter) after a retropubic MUS compared with a transobturator sling procedure (2.7% vs. 0%).
    • In addition, the rate of urinary retention (catheter for longer than 6 weeks) was also higher in the retropubic MUS group (3.7% vs. 0.7%).
  • There does not appear to be a consensus in the literature regarding preoperative factors that contribute to voiding dysfunction after MUS surgery.
  • The optimal evaluation for patients with postoperative voiding dysfunction is poorly defined in the literature. The decision to perform urethrolysis is usually based on a clear temporal relationship between onset of symptoms and the surgical procedure.
  • Cystoscopy is useful to rule out bladder pathology, urethral mesh perforation, and a hypersuspended bladder neck.
  • Management of Voiding Dysfunction after Midurethral Sling Surgery
    • Urinary obstruction after MUS surgery is usually transient and can be managed with short-term intermittent catheterization
    • For patients with persistently elevated residual urine and bothersome symptoms refractory to conservative management, transvaginal sling release procedures consistently provide resolution of symptoms with maintenance of continence in the majority of patients
      • Urethral dilation is of limited usefulness and, if used too aggressively, may be detrimental.
      • Cutting the MUS in the midline through a single vertical vaginal incision using minimal dissection is the preferred method to manage persistent voiding dysfunction that results from an obstructive sling within the first 3 months after surgery; the entire sling does not need to be excised
        • The exact timing of sling incision is variable; however, most recommend waiting at least 2 weeks; the sling should be incised within 4 weeks of surgery
        • The majority of patients maintain continence with single incision
      • After 3 months, the sling may be fixed along its entire course, and midline sling incision may not achieve enough sling relaxation to resolve voiding dysfunction. In these cases, we perform a more formal sling excision and urethrolysis
• Sexual Dysfunction after MUS
  • Contradictory evidence in the literature that MUS surgery improves and worsens sexual function
    • Some attribute improved sexual function after MUS surgery to a significant decrease in coital incontinence
    • The rate of de novo dyspareunia after MUS surgery is between 3-14%; sling removal can improve dyspareunia
• Other Complications after MUS Surgery
  • Infection, bleeding, vascular injury, bowel perforation, and death.
    • Risk of major vascular injury higher with retropubic vs. transobturator
    • The majority of postoperative hematomas resolve without intervention
  • UTI is the most common and easily treatable complication of MUS surgery.

Regulatory and Legal Issues Related to Sling Mesh Complications

• See CUA/AUA Mesh Position Statements
• The success of MUSs for incontinence led to the development of mesh products for pelvic organ prolapse repair. However, while the use of mesh during pelvic organ prolapse repairs has increased, so too have complications related to its use.
• In October 2008, the FDA released a public health notification (PHN) alerting the public about “rare” complications and problems related to transvaginal mesh products used for pelvic organ prolapse. In 2011, the FDA modified this alert by removing the term “rare” and stating that surgical mesh for pelvic organ prolapse repair does not conclusively improve outcomes over traditional nonmesh or native tissue repairs and is associated with unique potentially serious adverse outcomes
• FDA advisory panel deemed existing MUS products “safe and effective”
• Even though the FDA has determined that existing MUS products are safe and effective, this unfortunately does not prevent MUSs from being caught up in the fervor of litigation related to products used for pelvic organ prolapse repair.
• Single-incision sling manufacturers are required to perform 522 postmarket surveillance studies

Pubovaginal Slings (PVS)

• Indicated for treatment of incontinence associated with a deficiency in a portion of the midurethral complex, hypermobility, ISD, MUI, concomitant cystoceles, urethral diverticula, and neurologic conditions
• Anatomy and Mechanics of a PVS
  • Positioned at the bladder neck to provide urethral compression without obstruction during times of increased intraabdominal pressure.
  • The current concept of PVS comes from using a shorter free graft of rectus fascia whose tension could be adjusted
• PVS Sling Materials
  • Autologous, allograft, xenograft, and synthetic materials have been used for the construction of a PVS
  • Although there is complete biocompatibility of the autologous sling and negligible urethral perforation, biologic graft and synthetic prosthetic materials have been increasingly used to decrease operative time, morbidity, pain, and hospital stay
  • Autologous fascia PVS
    • Gold standard for management of ALL forms of SUI
    • Advantages compared to alternative sling materials (2):
      1. Minimal tissue inflammation
      2. Negligible risk of urethral erosion
    • Disadvantages compared to alternative sling materials (2):
      • Increased operative time, hospital stay, postoperative pain, risk of suprapubic wound seroma, and risk of incisional hernia
    • Most commonly used autologous materials (2):
      1. Rectus abdominis fascia harvested from the abdominal wall
         • Most commonly used
      2. Fascia lata harvested from the lateral thigh
         • Fascia lata is the preferred autologous material for PVSs in patients with a history of prior ventral hernia repair; unlike rectus facia, the recovery time is less and there is no risk of future abdominal hernia formation.
         • Disadvantages of fascia lata compared to rectus abdominis:
           1. Requires repositioning of the patient
           2. Increased operative time
           3. Operating in an area unfamiliar to most pelvic surgeons
      3. Improvement of SUI is similar with rectus abdominis fascia or fascia lata PVS
  • Allograft PVS
    • Were introduced in an effort to reduce overall morbidity, operative time, and pain related to graft procurement
    • Currently derived from either cadaveric fascia lata or acellular human dermis
    • Allografts from cadavers raise the concern of potentially transmitting illnesses such as HIV, hepatitis, and Creutzfeldt-Jakob prion disease
      • The estimated risk of HIV transmission from an allograft is 1 in 1,667,600.
      • The theoretical risk of developing Creutzfeldt-Jakob disease from a non-neural allograft is 1 in 3.5 million.
    • Tissue-processing techniques for allografts may disrupt the microstructure and affect their strength properties
      • Maximum load to failure, maximum load/graft width, and stiffness are significantly lower for the allograft freeze-dried fascia lata group compared with the autologous, solvent-dehydrated, and dermal graft groups
  • Xenograft PVS
    • The forms of xenograft used are porcine dermis, porcine small intestinal submucosa, and bovine pericardium
    • Less tensile strength than allograft in situ and highest propensity to encapsulate
  • Synthetic PVS
    • The most commonly used synthetic material for PVSs is polypropylene mesh.
    • Advantages:
      • Almost unlimited supply of artificial graft material in various sizes and shapes, consistency in quality, elimination of harvest site complications, and decreased operative time.
      • More uniform, consistent, and durable compared with biologic grafts
      • Sterile, biocompatible, and noncarcinogenic
      • Lowest amount of degradation or disruption and the highest amount of fibroblast ingrowth and tissue ingrowth into the specimen
    • Disadvantages
      • Significant inflammatory and foreign body reactions
      • Higher rates of graft infection, urinary tract perforation, and vaginal exposure
        • No longer used to due risk of complications
• PVS Operative Procedure
  • Patient Counseling
    • If a synthetic prosthetic or biologic graft material is being used, surgeons should thoroughly counsel their patients about the permanent nature of these products and the unique and sometimes serious complications related to their use.
    • Patients should also be counseled about the risk of transient and permanent voiding dysfunction after surgery, including (2):
      1. Postoperative difficulty emptying the bladder
      2. De novo urgency and frequency
  • Graft Harvest for Autologous Pubovaginal Sling
    • Closure of the rectus fascia without tension is sometimes problematic. To prevent this difficulty, it is important to maintain a distance of ≥2 cm from the pubic symphysis
    • If undermining the fascial edges does not adequately mobilize the fascia, than interposition of a segment of synthetic mesh or graft may be necessary.
  • Pubovaginal Sling Vaginal Approach
  • Pubovaginal Sling Placement and Fixation
    • The bladder must be completely drained before passage of the Stamey needles to avoid inadvertent bladder injury
    • It is recommended to perform a cystoscopy after trocar passage to ensure integrity of the bladder and at the time of sling tensioning to visualize the bladder neck
    • A sling should never be tensioned before the weighted speculum is removed and the vaginal incision is closed. Tensioning before this may result in failure of the procedure due to too much or too little tension. The abdominal incision is closed after the sling is tensioned.
    • No suture fixation to the underlying periurethral fascia is necessary to anchor the sling  
  • Pubovaginal Sling Postoperative Care
• Outcomes of PVS for Predominantly SUI
  • No risk factors that consistently predict outcomes
  • PVS are particularly helpful in treating ISD
  • The reported cure rate of PVS surgery for recurrent SUI is excellent
  • Autologous PVS
    • Continence rate after PVS ranges from 61-97%; wide range due to variation in outcome definition
    • Postoperative de novo or urgency incontinence rates range from 2-21%
      • Most common reason for failure/patient dissatisfaction relates to urgency symptoms and urgency incontinence at follow-up
  • Allograft PVS
    • Limited outcome data, and the efficacy and durability of these slings are questionable
    • Previously reported failures coupled with the consistent success and rapid adoption of synthetic MUSs has led to abandonment of all types of cadaveric allograft at most centers.
  • Xenograft PVS
    • Because of the morbidity of autologous fascial harvest, high failure rates of allograft materials, and high exposure and perforation rates with synthetic PVSs, xenografts are an attractive option.
    • In general, they are associated with a low rate of infection, exposure, and perforation owing to their incorporation into host tissue cure rates comparable to those of the autologous sling.
    • In RCTs, porcine dermis was associated with significantly inferior long-term cure rates compared with the autologous PVS
• Outcomes of Autologous PVS for Mixed Urinary Incontinence
  • Overall, PVS remains an effective treatment option for MUI with cure rates similar to those of simple SUI.
    • The treatment of patients with mixed urgency and SUI is complicated and often involves a combination of anticholinergic therapy and surgery
    • PVS is an effective treatment option for stress-induced DO with cure rates similar to those of simple DO.
    • Anti-incontinence surgery may cure or aggravate urgency symptoms or lead to de novo urgency. This aspect of anti-incontinence surgery is unpredictable and a major cause of patient dissatisfaction
    • The presence of residual urgency is similar to de novo urgency with a PVS.
• Outcomes of Autologous PVS for Urethral Reconstruction
  • Autologous PVSs in the setting of urethral reconstruction (urethral fistula, urethral diverticulum, destroyed urethra) has excellent results when compared with other surgeries for incontinence
• Voiding Dysfunction Secondary to Bladder Outlet Obstruction after PVS
  • PVS is associated with higher success rate but increased risk of post-operative voiding dysfunction compared to the Burch colposuspension
    • SISTEr (NEJM 2007)
      • Population: 655 women with SUI
      • Randomized to autologous rectus fascia PVS vs. Burch colposuspension
      • Results
        • Success rates higher for PVS
        • Voiding dysfunction (63% vs. 47%, P < .001), UTI, difficulty voiding, and postoperative urgency incontinence higher for PVS
      • Albo, Michael E., et al. "Burch colposuspension versus fascial sling to reduce urinary stress incontinence." New England Journal of Medicine 356.21 (2007): 2143-2155.
  • The presentation of patients with obstruction by a PVS is variable and the symptoms range from complete urinary retention, impaired detrusor, detrusor overactivity contractility and urgency incontinence to the less obvious irritative symptoms.
    • Persistent/increasing urgency incontinence and urgency (8-25%) are more common presenting symptoms in bladder outlet obstruction after a PVS procedure than frank retention
    • The incidence of permanent retention is usually ≤ 5%; the majority of patients who require clean intermittent catheterization after PVS placement had a neurogenic bladder preoperatively
  • There are no well-established risk factors for patients who are likely to experience voiding dysfunction after PVS surgery. Although urodynamic studies are useful in understanding the voiding dynamics of incontinent women, low detrusor pressure and Valsalva voiding preoperatively should not exclude patients from having an anti-incontinence procedure.
  • Although postoperative urgency and urgency incontinence (voiding dysfunction) are strongly related to failure, there are no preoperative risk factors that consistently predict these outcomes after PVS surgery.
  • Cystoscopy is useful to rule out bladder pathology, sling perforation, and a hypersuspended urethra.
  • The most important criterion for a sling incision or urethrolysis remains the temporal relationship between the symptoms and the surgical procedure. Urodynamic studies are essential in these cases to diagnose and make an appropriate treatment plan.
  • A key factor in assessing voiding dysfunction is the presence of prolapse that was either uncorrected at time of surgery or that occurred postoperatively. Prolapse of sufficient size may kink or angulate and externally compress the urethra. After surgery, apical, anterior, and posterior prolapse must be ruled out as a cause of the urethral obstruction.
  • Surgical Management of Voiding Dysfunction after PVS
    • See 2017 AUA Female SUI Guidelines Notes
    • Obstruction after an autologous PVS procedure usually improves or resolves with time; although transient urinary retention is common, most patients return to spontaneous voiding within the first 10 days
    • In the first 6 weeks after autologous PVS surgery, loosening the sling in the operating room (using spinal or general anesthesia) can be attempted. This is done by first inserting a cystoscope into the bladder and then gently applying caudal pressure to the urethra. This procedure is not advised with synthetic slings
    • After 6 weeks or when conservative measures fail, a formal urethrolysis by a retropubic, transvaginal, or suprameatal approach or sling incision is indicated.
      • Sling incision has comparable success rates and shorter operative time and less morbidity than formal urethrolysis
      • Reported success rates of the surgical management of bladder outlet obstruction after a PVS procedure are 65-93%
      • Recurrent SUI after formal urethrolysis is reported as 0-19% and 34% after sling incision
    • There are no preoperative or urodynamic parameters that consistently predict success or failure of urethrolysis.
    • Failure of urethrolysis may be caused by persistent or recurrent obstruction, DO, impaired detrusor contractility, or learned voiding dysfunction. The most common reason for failure is likely insufficient dissection and lysis of the urethra. This supports the use of repeat urethrolysis in the face of initial failure or in cases wherein the aggressiveness of the initial dissection is unknown.
    • OAB symptoms are refractory in 50% of affected patients after urethrolysis and contribute to a significant portion of the reported failures. Refractory storage symptoms after urethrolysis can be challenging to treat. In addition to anticholinergics, SNM should be considered as an option for de novo or refractory urgency and urgency incontinence after urethrolysis.
• Complications of Pubovaginal Slings
  • Mesh located in the lower urinary tract is termed a perforation, and extrusion of mesh through the skin or vagina is termed exposure
  • Pubovaginal Sling Perforation and Exposure
    • The incidence of PVS perforation and exposure is partially dependent on the composition of sling material.
      • Synthetic slings perforate 15x more often into the urethra and are exposed 14x more often in the vagina than autologous, allograft, and xenograft slings. The perforation or exposure of autologous PVSs is rare
        • Urethral perforation rate was 0.02% and the vaginal exposure rate was 0.007% in 1515 patients who received synthetic slings.
        • Urethral perforation incidence of 0.003% and a vaginal exposure incidence of 0.0001% in 1715 patients undergoing autologous and allograft sling procedures.
    • Urethral perforations present at ≈9 months
    • Presenting symptoms often include urinary retention, urgency, and mixed incontinence. In addition, synthetic sling perforations and exposures are also associated with vaginal discharge, vaginal pain, suprapubic pain, and recurrent UTIs.
    • Management of autologous and allograft PVS urethral perforation usually involves incision or excision of the part of the sling that has perforated and simple closure of the urethra
    • The incidence of recurrent SUI after synthetic PVS urethral perforation is 44-100%, and treatment often involves a second PVS
    • Because urinary tract perforation and vaginal exposure of synthetic PVSs are more common and associated with significant morbidity, synthetic material is no longer used for bladder neck slings
  • Non-urologic Complications of PVS
    • Most commonly pulmonary, cardiovascular, neurologic, and gastrointestinal (bowel injury)
• Pubovaginal slings (PVS) are placed under mild tension at the bladder neck to reestablish the suburethral hammock and are able to improve SUI by providing a layer of tissue that compresses the urethra during times of increased intra-abdominal pressure.
• Unlike the PVS, the MUS should be placed loosely at the midportion of the urethra to prevent movement of the posterior urethral wall

Burch colposuspension

• Largely replaced by MUS
  • Several RCTs showed essentially equivalent outcomes with the Burch colposuspension vs. TVT
• Likely inferior to pubovaginal fascial sling
• Indications (2):
  1. Patient preference to avoid mesh and avoid the morbidity of fascial harvest
  2. Undergoing a simultaneous abdominal procedure, such as open or minimally invasive hysterectomy

Questions

1. In the integral theory, what components support the proximal and midurethra
2. What UDS values are suggestive of intrinsic sphincter deficiency?
3. List 5 differences between MUS and PVS
4. What are the most commonly used autologous materials in PVS?
5. What are advantages vs. disadvantages of synthetic PVS?
6. What were the main findings of the SISTEr trial?
7. What are the typical presenting symptoms in a patient with obstruction following PVS?
8. What is the surgical management of voiding dysfunction after PVS?
9. What is the management of PVS perforation?
10. What is the closest vascular structure related to the retropubic MUS approach?
11. How do outcomes in the elderly differ from the young after MUS surgery?
12. List complications associated with MUS
13. What is the management of urinary retention after MUS?

Answers

1. In the integral theory, what components support the proximal and midurethra
   1. Pubourethral ligaments
   2. Suburethral vaginal hammock
   3. Pubococcygeus muscle
2. What UDS values are suggestive of intrinsic sphincter deficiency?
3. List 5 differences between MUS and PVS
   • PVS: positioned at bladder neck, predominantly uses autologous material, complicated by donor graft morbidity, corrects ISD and hypermobility, can be used to correct SUI concomitant with urethral diverticular repair, higher risk of post-operative voiding dysfunction
   • MUS: positioned at midurethra, predominantly uses synthetic material, not complicated by donor morbidity, corrects hypermobility only, cannot be used to correct SUI concomitant with urethral diverticular repair, lower risk of post-operative voiding dysfunction
4. What are the most commonly used autologous materials in PVS?
5. What are advantages vs. disadvantages of synthetic PVS?
6. What were the main findings of the SISTEr trial?
7. What are the typical presenting symptoms in a patient with obstruction following PVS?
8. What is the surgical management of voiding dysfunction after PVS?
9. What is the management of PVS perforation?
10. What is the closest vascular structure related to the retropubic MUS approach?
11. How do outcomes in the elderly differ from the young after MUS surgery?
12. List complications associated with MUS
13. What is the management of urinary retention after MUS?

References

• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 84