
Urinary Incontinence: Not Just a Flow Issue
Stress Urinary Incontinence
Stress urinary incontinence (SUI) affects men and women worldwide, but women are disproportionately impacted. An estimated one in eight women will require surgical management for SUI or pelvic organ prolapse by age 80 years.[1,2] The gold standard of surgical care for SUI is a midurethral sling (MUS) using polypropylene mesh, as this procedure is minimally invasive and has reported success rates of 77%-90%.[3]
This slideshow presents female SUI first, followed by male SUI.
The intraoperative images above are from a transobturator MUS surgery in a female patient.
Urinary Incontinence: Not Just a Flow Issue
Female SUI
There are three theories regarding the cause of SUI: urethral hypermobility, suburethral hammock, and the integral theory.
Underlying the urethra is a supportive layer of endopelvic fascia and the anterior vaginal wall.[4] The fascial layer is attached laterally to the arcus tendineus fasciae pelvis (ATFP) and levator ani muscles. During stress maneuvers and increased abdominal pressure, the urethra is compressed against this supportive fascia layer, which prevents urinary leakage.[4] If there is a deficiency in these supporting structures and the urethra is hypermobile, then SUI results.
The pubococcygeal muscles insert at the level of the midurethra, just outside the vaginal epithelium, and play a vital role in midurethral continence.[4] The essence of the integral theory is that women need proper functioning of the pubourethral ligaments, the suburethral hammock, and pubococcygeus muscles for continence. The concept of slings for SUI came from these theories.
Urinary Incontinence: Not Just a Flow Issue
Sling Procedures
Pubovaginal slings (PVS) use a 2- to 3-cm width, 8- to 10-cm long strip of autologous fascia placed at the bladder neck under mild tension to reestablish the suburethral hammock and provide a layer of tissue that compresses the urethra during times of increased abdominal pressure.[5] Incorporation of PVSs into the endopelvic fascia, subsequent fibrosis, and eventual fixation of the sling in the retropubic space prevents SUI.
MUSs are placed loosely at the midurethra to impede movement of the posterior urethra, directing its motion in an anteroinferior or anterior direction.[5] The slings are anchored in the endopelvic fascia or obturator internus and externus muscle/fascia. Over time, the mesh becomes fixed and provides support along its entire course, not just the midline.
Urinary Incontinence: Not Just a Flow Issue
The images show an example of polypropylene mesh (left) and its close-up (right) used to prepare transobturator tape in the treatment of female SUI.
Complications
Postoperative complications of using mesh for SUI include mesh erosion, infection and exposure, voiding dysfunction, and pelvic pain.[6] Prevalent pain symptoms include dyspareunia and pelvic, vaginal, or buttock pain related to the distribution of the obturator or pudendal nerve.[7,8] In a review article covering the years 2008-2011, the reported composite MUS erosion/exposure rate was 0%-7.3%; dyspareunia, 0%-6.2%; and overall pelvic/groin pain, 0%-16.6%.[7]
Thigh and groin pain are more commonly associated with the transobturator (16%) rather than the retropubic (1.5%) approach.[9] Persistent pain also appears to be more commonly associated with the transobturator (32%) than retropubic approach (10%),[10] although Doo and colleagues noted persistent pelvic pain in 2.2% of women 5 years following retropubic sling placement.[11]
Urinary Incontinence: Not Just a Flow Issue
This cystoscopic view shows mesh from the urethra perforating the bladder wall to wall.
Mesh erosion presents as vaginal discharge, blood, sexual discomfort, urinary symptoms, or a palpable rough surface in the vagina.[6] Many authors advise observation for exposures less than 1 cm because the area may heal spontaneously.
Mesh erosion is treated with sequentially increasing invasiveness, starting with observation or the administration of conjugated estrogen or antibiotic creams (eg, clindamycin or metronidazole).[6] If mesh exposure is still noted after 3 months, limited excision and trimming with vaginal closure can be attempted, followed by transvaginal excision of the entire mesh if all other conservative measures fail.[6]
Urinary Incontinence: Not Just a Flow Issue
The incidence of sling perforation into the urethra after MUS is very low at 0%-0.6%.[6] Contributing factors include a compromised urethral blood supply (radiation, estrogen deficiency); excessive sling tension; excessive dissection too close to the urethra; iatrogenic, traumatic urethral dilation; and pressure necrosis from rolling of the sling. Patients will usually present with voiding dysfunction.
Sling perforation can be diagnosed with cystoscopy; treatment is sling excision.[6] Another complication requiring sling excision is perforation of the sling into the bladder (shown). The incidence is 0.5%-0.6% and most often occurs secondary to an undetected trocar injury during sling placement. Patients present with abdominal pain, hematuria, voiding complaints, or recurrent urinary tract infections (UTIs). Small areas can be managed with endoscopic excision with scissors or ablation with a holmium laser; however, large areas may need to be managed with full sling excision and possible partial cystectomy.[6]
Urinary Incontinence: Not Just a Flow Issue
The pelvic floor sonogram (sagittal plane) shows a small hematoma between a tension-free vaginal tape and the urethra that compressed the urethra, leading to transient voiding problems. Surgery was not required. BN = bladder neck, H = hematoma, and S = symphysis pubis.
The incidence of voiding dysfunction after PVS varies from 2.5% to 35% in the literature. A meta-analysis by the American Urological Association (AUA) Stress Urinary Incontinence Clinical Guidelines Panel showed that the rate of urinary retention more than 4 weeks after PVS was 8%, and the risk of permanent retention "generally does not exceed 5%."[12] The overall incidence of urinary obstruction requiring intervention after MUS is 8%.[12]
Richter et al found a significantly higher rate of voiding dysfunction necessitating surgery (permanent catheter) after retropubic versus transobturator MUS (2.7% vs 0%); the rate of urinary retention was also higher with retropubic than transobturator MUS (3.7% vs 0.7%).[13] This urinary retention is usually transient and managed with short-term clean intermittent catheterization (CIC).[6]
Urinary Incontinence: Not Just a Flow Issue
Pelvic Organ Prolapse
Pelvic organ prolapse (POP) is caused by weakness in the pelvic floor muscles and fascial and ligamentous attachments.[14] Uterine prolapse is the herniation of the uterus into or beyond the vagina and often coexists with prolapse of the vaginal walls, involving the bladder or rectum.
The anatomic support of the vagina has been well described by DeLancey at three levels.[14,15] Level 1 supplies the apical support and consists of the cardinal-uterosacral ligament complex, which provides apical attachment of the uterus and vaginal vault to the sacrum. Uterine prolapse occurs when the cardinal-uterosacral ligament complex breaks or is weakened. Level 2 supports the middle of the vagina, which includes the lateral connections of the vagina to the ATFP and the fascia overlying the levator ani muscles. Level 3 supports the lower part of the vagina, the urogenital diaphragm and the perineal body.[14,15]
Urinary Incontinence: Not Just a Flow Issue
The symptoms of POP include the sensation or visualization of a vaginal bulge, urinary urgency, frequency, incontinence, incomplete voiding, straining to defecate, using manual digitation/reduction of the prolapse to aid in starting the urinary stream or in defecation, dyspareunia, vaginal pressure, and fecal incontinence.[14,16] For the diagnosis, pelvic examination with the patient at rest and straining during a Valsalva maneuver should be used.
Prolapse is graded as follows[14,17]:
- Stage 0: No prolapse
- Stage I: The most distal portion of the prolapse is >1 cm above the level of the hymen.
- Stage II: The most distal portion of the prolapse is ≤1 cm proximal or distal to the hymen.
- Stage III: The most distal portion of the prolapse is >1 cm below the hymen but protrudes no further than 2 cm less than the total length of the vagina.
- Stage IV: Complete eversion of the vagina
Urinary Incontinence: Not Just a Flow Issue
The extent of the prolapse does not correlate well with the symptoms, and if the prolapse is minimal, then watchful waiting is usually appropriate. If incontinence is present with prolapse, then conservative measures such as pelvic floor muscle therapy can be used to treat the incontinence but will not improve the POP itself. The only nonsurgical method for treatment of the prolapse is a pessary.
In a prospective study of 100 women with symptomatic POP fitted with a pessary, 73 women retained the pessary 2 weeks later.[18] After 2 months, 92% of these women were satisfied with their pessary; resolution occurred for almost all prolapse symptoms and 50% of urinary symptoms. In addition, occult SUI was uncovered in 21% of patients after pessary placement, which is similar to postsurgical findings of occult SUI after POP repair without concomitant sling placement.[18]
Pessaries can also be used to treat SUI and are useful in short-term situations until a woman can undergo surgery. They should be removed and left out overnight two to three times a week. Patients who cannot remove their pessaries themselves require office examinations every 3 months to assess the vaginal walls for erosion.[19]
Urinary Incontinence: Not Just a Flow Issue
POP surgeries
In the United States, over 200,000 surgeries for prolapse are performed every year,[20] with reoperation rates as high as 30%.[21] US women have a 13% lifetime risk of undergoing POP surgery.[2] Between 2003 and 2012, there was a dramatic increase in the number of POP surgeries performed by urologists, with a similar increase in mesh use.[22] (A 2018 study revealed that after the 2011 US Food and Drug and Administration [FDA] warning about complications with transvaginal mesh, the rate of POP surgery declined between 2010 and 2013 among privately insured US women.[23])
The most common area of prolapse is the anterior vaginal wall, with anterior colporrhaphy noted as a component of 81% of surgeries for POP.[21] When patients are interested in surgery, several studies have demonstrated a relationship between anterior/posterior vaginal wall prolapse and vaginal apical support.[19] Many investigators argue that adequate suspension of the apex is the foundation of a successful prolapse repair. The next step is to determine if a patient would prefer an obliterative or reconstructive surgery.[19]
Urinary Incontinence: Not Just a Flow Issue
Colpocleisis is an obliterative surgery reserved for elderly women who are no longer interested in sexual intercourse. With regard to vaginal reconstruction, sacrospinal ligament fixation (shown) is the best studied procedure for apical prolapse relative to abdominal sacroculpopexy, with a cure rate of 63%-97%.[19] This is an extraperitoneal procedure and requires hysterectomy. Complications most often associated with sacrospinal ligament fixation are postoperative dyspareunia, gluteal pain, and anterior vaginal wall recurrence.
Vaginal ureterosacral ligament suspension involves intraperitoneal suture placement. Complications of this procedure include ureteral obstruction, nerve injury, and suture erosion.[19]
Urinary Incontinence: Not Just a Flow Issue
A 2018 multicenter trial that compared the two vaginal approaches (sacrospinal ligament fixation vs ureterosacral ligament suspension) found that, at 5 years, both had similar anatomic, functional, and symptomatic outcomes.[24] Cystocele repair alone without apical repair, however, has high recurrence rates of up to 41% reported in the literature[21]; use of anterior colporrhaphy (shown) for the treatment of urinary incontinence practically ceased after the AUA Female Stress Urinary Incontinence Clinical Guidelines Panel meta-analysis found a nearly 40% failure rate.[12]
A 2011 Cochrane review for prolapse surgery concluded that open abdominal sacral colpopexy was better than vaginal sacrospinous ligament suspension, with a lower rate of recurrent vault prolapse and less postoperative dyspareunia.[25] Robotic and laparoscopic abdominal sacroculpopexy have been shown to have similar efficacy to open approaches and with quicker recovery times.[19]
Urinary Incontinence: Not Just a Flow Issue
SUI and POP
The pathophysiology of SUI comes from reduced support of the endopelvic fascial layers surrounding the pelvic floor and weakness of the levator ani muscles around the bladder neck and urethra.[26] The cause of POP is similar to that of SUI, therefore the two conditions often coexist. Risk factors for both conditions include pregnancy, vaginal parity, forceps or difficult vaginal deliveries, advanced age, menopausal status, prior pelvic surgeries, obesity, and chronic straining.[26] In the Women’s Health Initiative, older age and a body mass index greater than 30 kg/m2 conferred a 40%-75% increased risk of prolapse.[27]
The lifetime risk that a woman in the United States will have surgery for prolapse or urinary incontinence is 11% by age 58 years and 20% by age 80 years; the cumulative risk is 13.6% for SUI surgery and 12.6% for POP surgery.[2] Up to one third of the surgeries represent repeat procedures.[21] The US Census Bureau projects the number of older women (≥65 years) in 2020 will be over 31 million; by 2030, it be more than 40 million.[28] As age is a risk factor for POP and SUI, the demand for healthcare services related to pelvic floor disorders will continue to rise.
Urinary Incontinence: Not Just a Flow Issue
In elderly women, there is a higher rate of detrusor overactivity, urgency incontinence, intrinsic sphincter deficiency, and impaired contractility.[5] Cure rates and intraoperative complications in elderly patients with urethral hypermobility are comparable to those of younger women; however, higher rates of age-related morbidities are possible. After MUS, there is also a greater incidence of postoperative voiding dysfunction, increased de novo urgency, and persistent SUI in the elderly.[6]
With regard to POP alone, genetic factors may play a role, as demonstrated in a study of 108 women with and without POP in which there was a higher risk of prolapse in women with a mother (odds ratio [OR]: 3.2) or sister (OR: 2.4) who also reported having prolapse.[29] The Pelvic Organ Support Study found that the risk of POP doubled with each decade of life,[30] whereas the Oxford Family Planning Association Study of 17,000 women found that increasing parity was associated with an increasing severity of prolapse.[31] Women with two vaginal deliveries were 8.4 times more likely to have surgery for prolapse.[31]
Urinary Incontinence: Not Just a Flow Issue
The least invasive surgical option for patients with SUI is the use of urethral bulking agents, which improves coaptation of the urethra. This procedure can performed in the outpatient setting with no need for general anesthesia and with minimal discomfort. Outcomes are best achieved in patients with intrinsic sphincter deficiency.[32]
As shown in the above image, the injection is administered through a cystoscope with one of three different FDA-approved products: silicon microparticles (Macroplastique), pyrolytic carbon-coated zirconium oxide beads (Durasphere), or calcium hydroxyapatite particles (Coaptite).
Urinary Incontinence: Not Just a Flow Issue
Urinary Urgency Incontinence
Urinary urge incontinence involves a sudden urge to urinate followed by involuntary urine loss. When conservative medical management for urinary urgency incontinence fails or medication side effects are intolerable, patients can undergo intravesical injection of onabotulinumtoxinA (ONA) (Botox). However, the patient must be willing and able to (1) return for frequent postvoid residual evaluation and (2) perform self-catheterization, if necessary. Urologists inject ONA into the detrusor muscle using either a flexible or rigid cystoscope and an injector needle. Complications of this procedure include urinary retention, UTI, and hematuria. Diabetic patients should be counseled that they have higher postoperative rates of urinary retention and UTIs.
In a study comparing ONA with anticholinergic therapy for urinary urgency incontinence, Visco et al found similar rates of reduction.[33] However, the ONA group was not only less likely to have dry mouth and more likely to have complete resolution of urgency urinary incontinence, but it also had higher rates of posttreatment UTI and transient urinary retention.[33]
Urinary Incontinence: Not Just a Flow Issue
Sacral neuromodulation is another option for urinary urgency incontinence that is refractory to more conservative treatments, although the mechanism of action for this therapy remains incompletely understood. Patients undergo a trial period with placement of either a percutaneous lead in the outpatient setting or a permanent lead in the operating room. If the patient experiences an improvement of more than 50%, the second-stage is performed with placement of an implantable generator.
Findings from the prospective InSite trial, which included patients with severe and those with mild frequency and incontinence, revealed an 81% success rate for incontinence and 78% for reduced frequency at 24 months.[34] The ROSETTA (Refractory Overactive Bladder: Sacral NEuromodulation vs BoTulinum Toxin Assessment) trial compared sacral neuromodulation (InterStim) with ONA (Botox) and found no significant difference between these treatments in the reduction of urgency urinary incontinence symptoms.[35] However, the ONA group reported higher patient satisfaction and treatment efficacy, albeit with a higher rate of UTI.[35]
Urinary Incontinence: Not Just a Flow Issue
Another neuromodulation device that can be employed for urinary incontinence associated with urgency is peripheral tibial nerve stimulation (PTNS).[36] The tibial nerve contains nerve roots from L4 to S3; PTNS is believed to cross-signal the posterior tibial nerve to the nerve circuit innervating the lower urinary tract. A fine needle is inserted about three finger breadths above the medial malleolus and angled at 60° between the posterior margin of the tibia and soleus muscle. The needle is then attached to an external low-voltage generator (an example is shown above). This therapy is performed in an outpatient setting for one to three 30-minute sessions every week for 12 sessions.[36]
Several studies have shown improvement in urinary urgency incontinence and frequency with PTNS relative to sham intervention. Other studies have suggested improved to similar efficacy compared with oral medications, but PTNS was associated with less side effects (eg, dry mouth, constipation) versus oral medications.[36]
Urinary Incontinence: Not Just a Flow Issue
The abdominopelvic computed tomography (CT) scan was obtained in a patient with abdominal pain and urinary incontinence associated with coughing and sneezing. Placement of a urinary catheter returned almost 1 liter of urine.
Overflow Incontinence
Overflow incontinence, in which urine loss is associated with bladder overdistention from urinary retention, is not the most common type of urinary incontinence, but clinicians should always keep it in mind.[37] This condition is more often seen in elderly male patients but can also affect female patients. A simple bladder scan after voiding can help clinicians to evaluate the emptying status of the patient; it is important to rule out overflow incontinence prior to initiating therapy for urinary incontinence, because many medications can worsen urinary retention.
Benign prostatic hyperplasia and urethral stricture are common etiologies of overflow incontinence in males, whereas in females, POP, urethral hypermobility, neurogenic bladder, or post sling surgery can lead to urinary retention.[37] Patients with overflow incontinence will typically present with symptoms of obstruction, including straining to void, having a weak stream, and having a feeling of incomplete voiding, as well as symptoms of both SUI and urinary urgency incontinence.[37]
Urinary Incontinence: Not Just a Flow Issue
Mental Health, Cognition, and Dementia
Multiple factors contribute toward urinary incontinence in the elderly, such as delirium, infections, atrophic urethritis/vaginitis, drugs, psychological disorders, excessive urine output, restricted mobility, and/or constipation.[38] In addition, seniors with urinary incontinence are at higher risk for associated feelings of depression, loneliness, and anxiety.[39]
Treatment for this subset of patients with urinary incontinence should be focused on alleviating any reversible disorders prior to medical or surgical therapy. Moreover, for geriatric patients with urinary incontinence associated with symptoms of overactive bladder, clinicians should use caution when administering certain classes of anticholinergic medications, as they have been shown to worsen dementia and cognition.[40] Beta-3 agonists such as mirabegron may be a better option for these patients; however, note that mirabegron has the potential to worsen hypertension.[41]
Urinary Incontinence: Not Just a Flow Issue
Male SUI
SUI in men is the involuntary leakage of urine secondary to weakened outlet resistance.[42] Quality of life is significantly impacted and reduced in affected male patients. The most common cause of male SUI is prostate surgery, namely radical prostatectomy (shown). Additional causes include pelvic fracture with associated urethral injury, transurethral resection of the prostate (especially with previous pelvic radiation), and other types of pelvic surgery and congenital disorders.[42]
Prior to any surgical intervention, the patient’s pad weight and voiding diaries should be evaluated. Moreover, because urinary incontinence tends to improve after radical prostatectomy, many centers recommend a waiting period of at least 1 year before surgical intervention. Two main procedures exist for operative treatment of male SUI: male sling and artificial urinary sphincter placement.[42] Urethral bulking, as in female patients, can also be used, but with less favorable outcomes.
Urinary Incontinence: Not Just a Flow Issue
Male patients with SUI who wish to proceed with surgical intervention must be appropriately selected and counseled. Male slings relocate the rhabdomyosphincter more proximally to provide improved urinary continence.[43] Male perineal sling placement most benefits men who have mild to moderate SUI and a functional rhabdomyosphincter.
Note that pad weight does not correlate well with the severity of the urinary incontinence. Sphincter function can be evaluated by having the patient report if they can stop their urine midstream or by cystoscopic evaluation.[42] Other factors include good bladder capacity and coaptation of the native sphincter in addition to the absence of an anastomotic contracture. The most common complications of male slings include perineal pain, urinary retention, infection, anchoring complications from bone anchors, and erosion (rare).[42]
Urinary Incontinence: Not Just a Flow Issue
The image shows the AMS 800 Artificial Urinary Sphincter. This device has three components: the urethral cuff, the pump located within the scrotum, and the pressure-regulating balloon.[44]
Implantation of an artificial urinary sphincter (AUS) is considered the gold standard for postprostatectormy male patients who have moderate to severe urinary incontinence.[45] However, studies are inconsistent regarding the end point definition of continence following AUS, with most studies using a definition of no pad use or one pad use per day for protection. The combined dry/improved rate of 12 pooled studies comprising data from 623 patients was 79%, with a range of 61%-100%.[45]
Complications of AUS include urethral cuff erosion and infection, usually occurring within 2 years of implantation in about 8.5% of cases.[45] When patients who have an AUS undergo surgical intervention, care must be taken to ensure the device is deactivated prior to urinary catheterization; urologic consultation can assist with this prior to surgery. Recent studies have shown an improvement in reducing pad use of up to three pads per day, with improved quality of life as well.[45]
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