AUTHOR AND EDITOR INFORMATION

Section 1 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

INTRODUCTION

Section 2 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Injectable therapy of bulking agents composed of synthetic materials, bovine collagen, or an autologous substance augment the urethral wall and increase urethral resistance to urinary flow. Injectable bulking agents used to treat a dysfunctional urethra is a minimally invasive method of correcting intrinsic sphincteric deficiency (ISD) that results in stress urinary incontinence (SUI).

History of the Procedure

Bulking agents have been used for the management of stress urinary incontinence for more than a decade, but their application has been limited by ease of placement, durability, and antigenicity or compatibility issues. The lack of a single reproducible injectable agent has led to the development and application of several agents that provide reasonable efficacy with minimal associated morbidity. Continuous development of injectable techniques and materials technology provide the basis for multiple new bulking agents. Clinical trials continue to provide evidence based experience with this form of minimally invasive solutions in the treatment of stress urinary incontinence.

Problem

Urinary incontinence is an underdiagnosed and underreported medical condition. An estimated 50-70% of women with urinary incontinence fail to seek medical evaluation and treatment because of social stigma. Only 5% of individuals who are incontinent and 2% of nursing home residents who are incontinent receive appropriate medical evaluation and treatment. Patients who are incontinent often cope with this condition for 6-9 years before seeking medical therapy.

ISD is the inability of the urethra to provide adequate urethral closure pressure that prevents involuntary loss of urine during increases in abdominal pressure.

Frequency

Urinary incontinence affects approximately 13 million people in the United States, predominantly women. Approximately 10-35% are adults. Approximately 50% of the 1.5 million nursing home residents are affected. As many as 60% of nursing home patients are incontinent, and 30% of elderly individuals living at home are incontinent.

Stress incontinence affects 15-60% of women—both young and old individuals. More than 25% of nulliparous young college athletes experience stress incontinence when participating in sports.

The presence of urethral hypermobility with mild-to-moderate ISD is the most common form of stress urinary incontinence in the overall female population; however, severe ISD is more prevalent in elderly women and rarely occurs spontaneously. More than 90% of women with severe ISD have had some form of pelvic surgery or trauma. Zaragoza (1996) has reported that, of 60 women undergoing pubovaginal sling surgery, 37% were diagnosed with severe ISD as their cause of stress urinary incontinence. Morgan et al (2000) have reported a 48% incidence of severe ISD in women who have undergone simple hysterectomy.

Etiology

ISD can result from the aging process, trauma, surgery, or neurologic dysfunction. The most common cause of ISD in men is surgery due to radical prostatectomy for prostate cancer or from transurethral resection of the prostate because of benign prostatic hyperplasia. A less common cause of ISD is trauma to the bladder neck or prostate, resulting from pelvic fracture due to high-impact deceleration injuries. In women, ISD may occur as a result of postmenopausal estrogen loss, previous bladder neck operations (eg, urethropexy, pubovaginal sling), or as a result of pelvic trauma. Patients with a neurogenic disorder such as myelomeningocele may have an open bladder neck that results in severe ISD and urinary loss.

Pathophysiology

ISD occurs as a result of devascularization and/or denervation of the bladder neck and proximal urethra. The urethral sphincter may become weak after pelvic surgery (eg, failed bladder suspension surgery) because of nearby nerve damage or excessive scarring of the urethra and surrounding tissues. Additional causes of urethral dysfunction are pelvic radiation or neurologic injury, including myelomeningocele. Women with severe ISD do not always have the usual urethral hypermobility during a Valsalva maneuver. Paradoxically, the urethra appears well supported. This results in lead pipe urethra, where the urethra remains open at rest. Whenever intra-abdominal pressure exceeds proximal urethral pressure, involuntary urine loss ensues. Because the urethra cannot remain closed in this setting, the patient experiences almost continuous urinary incontinence.

Clinical

Patients with severe ISD as the cause of their stress urinary incontinence present with symptoms typical of stress incontinence, but the symptoms are much worse. Patients report involuntary urine loss when coughing, laughing, and sneezing. They also describe urine loss when standing up from a sitting position. If the problem is severe, patients describe continuous dribbling of urine and typically require a high volume of pad use.

Patients with mild ISD and minimal urethral hypermobility typically do not report irritative voiding symptoms such as urinary frequency, urgency, and nocturia. The presence of irritative voiding symptoms should raise an index of suspicion for overactive bladder. In addition, irritative voiding symptoms in combination with hematuria (gross or microscopic) warrant a complete bladder tumor workup.

A detailed pelvic examination in patients with severe ISD causing their stress urinary incontinence often reveals a well-supported urethra with minimal urethral hypermobility. During a Valsalva maneuver, the resting Q-tip excursion angle is less than 30°.

Signs of estrogen deficiency such as atrophic vaginitis, vaginal mucosa with absent rugae, and thinned-out shiny vaginal epithelium may be observed. These patients demonstrate a positive finding on cough stress test either in a lithotomy or in a standing position if their bladder is relatively full.

A vaginal speculum examination in patients with mild or moderate ISD-caused stress urinary incontinence demonstrates a poorly supported urethra with urethral hypermobility. During a Valsalva maneuver, the resting Q-tip excursion angle is greater than 30°. The vaginal mucosa manifests normal rugae. In addition, signs of pelvic support decay also may be present. They include cystocele, rectocele, enterocele, and uterine descensus. Patients who have had prior hysterectomy may have signs of vaginal vault prolapse.

Patients with coexisting pelvic organ prolapse may report dyspareunia, vaginal pain upon ambulation, and a bulging sensation in the vagina. Patients with severe pelvic organ prolapse may experience herniation of pelvic organs out of the vaginal introitus, necessitating manual reduction. Patients with symptomatic rectoceles report severe constipation, often necessitating digital disimpaction. Severe cystoceles may drag both ureters through the true pelvis as the bladder herniates out of the vagina, causing renal azotemia. Bilateral hydroureteronephrosis occurs because ureters become compressed against the bony pelvic inlet, resulting in ureteral obstruction.

INDICATIONS

Section 3 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Social indications for surgical intervention are any stress incontinence that interferes with the patient's quality of life. Pathological indications for correcting ISD are primary urethral dysfunction, failed previous bladder neck surgery, and severe attenuation of endopelvic fascia.

Treating ISD secondary to severe ISD is often more difficult than treating ISD induced by urethral hypermobility, which is why severe ISD is referred to as complex or complicated stress incontinence. If the urethra displays low outlet resistance, treatment must be designed to increase outflow resistance.

Candidates for periurethral bulking agents include women with ISD and men who are incontinent after prostate surgery. For women with severe ISD or urethral hypermobility–induced ISD, the best long-term results are obtained with a sling or retropubic bladder neck suspension procedure. However, periurethral injection therapy has been introduced because of excellent short-term results as a minimally invasive procedure. For women with urethral hypermobility–induced ISD, early studies have reported favorable short-term results with injectables; however, long-term (>1 y) data are lacking. Incontinent men who fare best with injectable therapy are those who have stress incontinence after transurethral prostatectomy (TURP). Men with stress incontinence after radical prostatectomy have the least significant success rate with bulking agents, and these men may be treated best with a sling procedure or an artificial urinary sphincter.

RELEVANT ANATOMY

Section 4 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

The female urethra is a 4-cm elongated tube composed of an inner epithelial lining, a spongy submucosa, a middle smooth muscle layer, and outer fibroelastic connective tissue. The spongy submucosa contains rich vascular plexus that is responsible for providing adequate urethral occlusive pressure to create the washer effect, an important female continence mechanism. Urethral smooth muscle and fibroelastic connective tissues serve to circumferentially augment the occlusive pressure generated by the submucosa.

Female urethral function is influenced by estrogen. The lack of estrogen at menopause leads to atrophy and replacement of submucosa (ie, vascular plexus) by fibrous tissue. Previous bladder neck operations, radiation, and neurogenic disease can affect the patient's ability to achieve a perfect seal. When estrogen is administered to postmenopausal women with atrophic vaginitis, the mucosa regains its turgor, with simultaneous up-regulation of alpha-receptors and angiogenesis of vascular plexus. Lack of estrogen is a risk factor for developing ISD, but estrogen replacement may reverse its effects.

CONTRAINDICATIONS

Section 5 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Periurethral bulking agents should not be used in the setting of pure urge incontinence or bladder outlet obstruction. A patient with mixed incontinence (eg, stress and urge) and the urge component is the predominant problem may elect to address the symptoms of bladder overactivity prior to bulking up the urethra but may find that treatment of the stress urinary incontinence also improves the urge incontinence.

WORKUP

Section 6 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Lab Studies

• Urinalysis and urine culture rule out urinary tract infection.
• Urine cytology
• • Carcinoma in situ of the urinary bladder causes urinary frequency and urgency.
  • Symptoms of irritative voiding out of proportion to the overall clinical picture and/or hematuria warrant urine cytology and cystoscopy.
• Check blood urea nitrogen (BUN) and creatinine (Cr) if compromised renal function is suspected.

Imaging Studies

• Cystogram (anterior-posterior and lateral)
• • Obtain a cystogram to assess bladder neck anatomy. Performing a static cystogram (anterior-posterior and lateral) helps to confirm stress incontinence or a cystocele, and it is used to determine the degree of urethral motion. An open bladder neck demonstrates ISD. The presence of a vesicovaginal fistula also may be noted.
  • A VCUG is used to assess bladder neck and urethral function (internal and external sphincter) during filling and voiding. Findings on voiding cystogram can reveal a urethral diverticulum, urethral obstruction, and vesicoureteral reflux.
  • Consider performing a static cystogram or VCUG at the time of videourodynamics.

Other Tests

• Voiding diary
• • A voiding diary is a daily record of a patient's bladder activity.
  • It is an objective documentation of a patient's voiding pattern, incontinent episodes, and inciting events associated with urinary incontinence.
• Pad test
• • This objective test documents urine loss.
  • Use intravesical methylene blue, oral Pyridium, or Urised. Methylene blue and Urised turn urine blue; Pyridium turns urine orange.
  • Ask patients to resume their usual physical activities while wearing a Peri-pad. If the pad turns orange or blue, the patient is experiencing urine loss. If the pad remains white, the patient most likely is experiencing normal vaginal fluid discharge.
• Cotton swab test
• • This test is performed by inserting a sterile lubricated cotton swab (Q-tip) into the female urethra. The cotton swab is passed gently into the bladder and then slowly pulled back until the neck of the cotton swab is fit snugly against the bladder neck. The patient then is instructed to perform a Valsalva maneuver or to contract the abdominal muscles. Excessive motion of the urethra and bladder neck (hypermobility) with straining is an important finding for type II stress incontinence. An abnormal upward deflection of the swab (>30°) by Valsalva maneuver is evidence of urethral hypermobility.
  • Absence of hypermobility suggests stress incontinence caused by ISD.
• Cough stress test
• • A critical part of the pelvic examination is direct observation of urine using the cough stress test or Marshall test.
  • The cough stress test is performed by filling the bladder with sterile fluid at least halfway (eg, 250 mL) and instructing the patient to bear down (Valsalva) or cough. Insert a sterile catheter into the urethra and fill the bladder with 200-250 mL of water. Remove the catheter.
  • Leakage during cough or Valsalva denotes a positive test result. The Marshall test, otherwise known as the Marshall-Bonney test, is performed by placing an index finger and the second finger on either side of the bladder neck. With the bladder relatively full, the patient is instructed to perform Valsalva or cough. Two fingers at the bladder neck serve to support the proximal urethra during Valsalva maneuver. The absence of leakage with bladder neck elevation and the presence of leakage with loss of bladder neck support confirm stress urinary incontinence due to urethral hypermobility. However, the Marshall test is neither sensitive nor specific enough to be used to diagnose stress urinary incontinence by today's standards. Thus, the Marshall test is not widely practiced today.
• Standing pelvic examination
• • Perform a standing pelvic examination if a standard pelvic examination fails to demonstrate urine loss or if pelvic organ prolapse is suspected.
  • If the cough leak test initially is performed while the patient is in the lithotomy position and no leakage is observed, repeat this test while the patient is standing. Observable urine leakage in this position indicates a positive test result. If any doubt remains about pelvic organ prolapse, examine the patient in the standing position.
  • Instruct the patient to stand with legs apart and one foot resting on a step stool. When the patient performs the Valsalva maneuver, the force of gravity helps the pelvic organs (eg, uterus, bladder) slide down the vagina and helps enhance diagnostic capability.
  • If pelvic prolapse is present, push the prolapsed organ up with a pessary or gauze and repeat the cough stress test with the patient in a standing position.
• Electromyography
• • Electromyography (EMG) helps to determine the presence of coordinated or uncoordinated voiding, and it is most useful in patients with a suspected neurologic disorder.
  • Failure of urethral relaxation during bladder contraction results in uncoordinated voiding (ie, detrusor sphincter dyssynergia).

Diagnostic Procedures

• Postvoid residual volume
• • The postvoid residual (PVR) volume measurement is part of the basic evaluation. 
  • If the PVR volume is high, the bladder may be acontractile or the bladder outlet may be obstructed. Both of these conditions cause urinary retention with overflow incontinence.
• Uroflow rate
• • Uroflow rate is a screening test mainly used to evaluate bladder outlet obstruction. 
  • The uroflow rate is the volume of urine voided per unit of time.
  • A low uroflow rate may reflect urethral obstruction, a weak detrusor, or a combination of both.
  • This test alone cannot be used to distinguish between obstruction and an acontractile detrusor.
• Filling cystometrogram
• • In 40% of patients, stress and urge incontinence coexist. In many instances, stress incontinence may lead to urge incontinence.
  • A filling cystometrogram is used to assess bladder capacity, compliance, and the presence of phasic contractions.
  • Most commonly, liquid filling medium is used. An average adult bladder holds approximately 450-500 mL of urine.
  • Provocative measures during the test help to unveil bladder instability.
• Abdominal leak point pressure
• • Measurement of abdominal leak point pressure (ALPP) is used to classify the severity of ISD. An important component of multichannel urodynamics (with or without fluoroscopy) is the determination of the ALPP.
  • ALPP (also known as Valsalva leak point pressure) is performed by instilling 250 mL of fluid medium into the urinary bladder. The patient is instructed to bear down (Valsalva) in gradients (mild, moderate, severe) to demonstrate leakage. The lowest abdominal pressure (P_abd) required to generate leakage is recorded as ALPP.
  • Cough leak point pressure (CLPP) is performed by instilling 250 mL of fluid medium into the urinary bladder. The patient is instructed to cough in gradients (mild, moderate, severe) to demonstrate leakage. The lowest P_abd required to generate leakage is recorded as CLPP.
  • Valsalva leak point pressure (compared to CLPP) appears to be more sensitive when diagnosing ISD because coughing and Valsalva seem to result in a different reaction of the pelvic floor. In addition, progressive bladder filling in 50-mL increments (eg, 250 mL, 300 mL, 350 mL) also appears to increase the sensitivity of leak point pressure testing. Leak point pressure testing may be performed with or without video (fluoroscopic) capabilities.
• Voiding cystometrogram (pressure-flow study)
• • Pressure-flow study simultaneously records the voiding detrusor pressure and the rate of urinary flow.
  • Only this test can be used to assess bladder contractility and the extent of a bladder outlet obstruction.
  • For complicated cases, combine pressure-flow studies with a voiding cystogram and videourodynamic study.
• Videourodynamic study
• • Videourodynamics is the criterion standard for evaluating patients with complex stress urinary incontinence. Videourodynamics combines the radiographic findings of voiding cystourethrogram (VCUG) and multichannel urodynamics. Videourodynamics is the most sophisticated diagnostic test for a patient with incontinence.
  • In the absence of videourodynamics, the clinician may obtain adequate information from the following:
  • • Noninvasive uroflow and PVR
    • Simple cystometry in combination with cystoscopy
    • Detailed speculum examination
    • Cough stress test and Q-tip test
    • Dynamic retrograde urethroscopy
• Cystoscopy
• • The precise role of cystoscopy in the evaluation of female urinary incontinence is controversial.
  • Fewer than 2% of bladder tumors have been identified upon routine performance of cystoscopy in incontinent women; however, cystoscopy is used to discover bladder lesions (eg, stitch in the bladder, bladder cancer, bladder stone) that would remain undiagnosed by urodynamics alone.
  • Visually inspecting the urethra helps to establish the presence of urethral stricture or gross evidence of poor urethral closure.
  • Cystoscopy is indicated for patients reporting persistent irritative voiding symptoms or hematuria.
  • Obvious causes of bladder overactivity (eg, cystitis, stone, tumor) are easily diagnosed. Cystoscopic information is important in determining the etiology of the incontinence, which may influence treatment decisions.
• Dynamic retrograde urethroscopy
• • Consider performing urethroscopy to assess the structure and function of the urethral sphincter mechanism.
  • Introduce the cystoscope into the bladder. Fill the bladder with 250 mL of irrigant. Turn off irrigant flow. Withdraw the cystoscope to the mid urethra. Observe the activity of the urethral sphincter mechanism at rest and with Valsalva maneuvers.
  • Patients with urethral hypermobility–induced ISD typically have a closed bladder neck at rest and an intact voluntary guarding reflex.
  • Patients with severe ISD have an open bladder neck at rest and an impaired voluntary guarding reflex.

TREATMENT

Section 7 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Medical therapy

Conjugated estrogens can help rejuvenate lead pipe urethra in women who are postmenopausal. Conjugated estrogen therapy (oral or topical) restores the mucosal seal and allows up-regulation of alpha-receptors to the female urethra. Administering estrogen in the setting of ISD is palliative and is not curative. Estrogen is used best in combination with alpha1 agonists.

Unfortunately, pharmacologic agents rarely are effective, and, when they are effective, adverse effects diminish the results. Behavior and dietary modifications have a rather limited role in the treatment of ISD.

Surgical therapy

Urethral bulking procedures are designed to treat stress incontinence from ISD by artificially inflating the submucosal tissues of the bladder neck. These procedures involve injecting synthetic and autologous fillers into the wall of the urethra to make it fuller. Bulking up the bladder neck with particulate matter effectively closes the lumen of the urethra, which improves urethral coaptation and restores the mucosal seal mechanism of continence.

Bulking procedures are minimally invasive and extremely useful for treating women with incontinence who wish to avoid open surgical procedures for various reasons.

Methods employed to bulk up the female urethra include transurethral or periurethral injection techniques. The delivery techniques for the male urethra include transurethral or antegrade injection.

Urethral bulking agents reported in the literature include polytetrafluoroethylene, silicone, carbon beads, autologous fat, and bovine collagen. Due to the risk of migration, Teflon and silicone are not approved by the US Food and Drug Administration (FDA) to treat female stress incontinence.

The only currently available injectable agents in the United States include collagen (Contigen), autologous fat, and carbon bead technology (Durasphere). Autologous fat is harvested from the lower abdomen and injected around the urethra. Glutaraldehyde, cross-linked collagen, is an extracted and purified bovine collagen. Durasphere is composed of pyrolytic carbon-coated beads suspended in a water-based gel. Newer agents under clinical trial evaluation include synthetic calcium hydroxylapatite, cross-linked hyaluronic acid (HA), and ethylene vinyl alcohol copolymer suspended in dimethyl sulfoxide.

The advantages of urethral bulking procedures are their simplicity, their minimal risk of associated complications, and their repeatability. Urethral bulking procedures may be performed as an outpatient procedure. Some surgeons perform these procedures quickly and painlessly in their offices if transurethral or periurethral techniques are employed. When antegrade approach is chosen, this procedure must be performed in the operating room because suprapubic access is necessary. After the injection, patients notice immediate results.

The disadvantage of these procedures is that the injectable agents may not produce a permanent cure. If stress incontinence persists after the initial injection, the surgeon can implant more material during subsequent follow-up visits. Long-term success is possible, but multiple reinjections are typically necessary.

Teflon paste

The best candidates for Teflon injections are women experiencing stress incontinence and incompetent urethra after a failed anti-incontinence operation, those with good anatomic support, and those with no history of pelvic radiation therapy.

Teflon is an inert plastic material that initiates a foreign body reaction and granuloma formation in the injection site. Teflon stimulates an ingrowth of fibroblasts that help to hold the Teflon particles within the periurethral tissues to facilitate inward compression of the urethral lumen.

The goal of this procedure is to create better coaptation and a better mucosal seal for the incompetent urethra by generating a cushioning effect with the Teflon paste. Simply stated, polytef paste adds bulk to the periurethral tissues and effectively closes the urethral lumen. The long-term success of a Teflon injection depends on whether a capsule forms around the injected paste. It is a simple procedure with a good cure rate, making it an excellent method for restoring urinary control.

The 2 disadvantages of Teflon injection are that it requires using a large-bore needle and that the US FDA has not approved it because of possible local and distant migration of the Teflon particles into the lymph nodes, lung, and brain.

Autologous fat

Autologous fat injection is a method of bulking up the urethra that uses fatty tissue extracted from the patient's lower abdomen. Autologous fat is an ideal bulking agent because it is inexpensive, readily available, and nonallergenic. Use this method in women with urinary incontinence caused by ISD. Ideal candidates are women with a clinical history of severe urinary incontinence who have good anatomic support. Although some investigators also use autologous fat for urethral hypermobility, long-term results of this application remain undetermined.

The injection technique is simple, and it does not employ foreign materials such as Teflon or bovine collagen. Injections may be repeated as required; however, the operative time of the procedure is prolonged because suprapubic fat must be harvested prior to periurethral injection. Before the US FDA approved collagen for use, fat injections were used to treat ISD by bulking up the urethra. The short-term result of periurethral fat injection is extremely good. However, over time, the injected adipocytes tend to be phagocytized by the patient's own body. This high degree of fat absorption is the major detriment to long-term cure.

Bovine collagen (Contigen)

A third type of bulking agent, bovine collagen (Contigen), is perhaps the best of all 3 bioinjectables for treating women with ISD. Collagen is a natural protein commonly found in animal bones and connective tissue. Collagen used to treat female urinary incontinence is extracted from cattle and then purified and prepared for use as a bioinjectable agent (cross-linked with glutaraldehyde). When collagen is injected around the urethra, the resultant bulking of periurethral tissue closes off the urethral lumen, which maintains urinary continence.

Collagen implantation usually is performed in the hospital in an outpatient setting, but it also can be performed in the office. During this procedure, collagen paste is injected carefully around the urethra near the bladder neck to bulk up the urethral tissue and stop urine from leaking. The injected bovine collagen gradually is replaced by the host collagen over the next 9-19 months. Usually, more than 1 treatment is necessary, and the procedure may need to be repeated after 1 year.

No known long-term complications from the injections exist. Contigen (CR Bard, Inc, Atlanta, Ga) is approved by the US FDA to treat male and female ISD. Patients being considered for periurethral collagen injection must be administered a skin test approximately 4-6 weeks before surgery to determine if they are allergic to this material.

Carbon bead particles (Durasphere)

Carbon bead particles (Durasphere) are an attractive alternative to currently available injectable agents. Carbon bead particles are nonbiodegradable bulking agents that may have similar efficacy with fewer adverse effects compared to bovine collagen. Durasphere has reported similar outcomes as collagen injections without the problem of early reabsorption. The material may be more difficult to inject than collagen because of increased viscosity and requires an 18- to 19-gauge needle for the injection. If any resistance to the injection is encountered, such as from scar tissue, the suspension gel tends to be injected first, leaving the carbon bead particles behind in the syringe.

Preoperative details

Injectable bulking therapy is performed predominantly in an outpatient setting, including in-office. Use a preoperative urine culture to check for infection. If using bovine collagen, administer a special skin test to patients 30 days before surgery to test for possible allergic reactions. Patients are typically given one dose of a prophylactic antibiotic because of the low risk of a bladder infection due to urethral manipulation.

Intraoperative details

Teflon paste injection

Perform the procedure with the patient under local anesthesia in the office or in the operating room. Position the patient in the dorsal lithotomy position. Prepare and drape the vaginal area in a sterile fashion. Gently instill local anesthetic (ie, 2% lidocaine jelly) into the urethral lumen. If additional anesthetic is needed, inject 1% lidocaine into the periurethral tissues next to the urethral opening. Insert the cystoscope into the urethra. Perform the entire procedure under direct vision using the cystoscope.

Inject the Teflon paste in 1 of 2 ways: periurethrally (ie, placed next to the urethra) or transurethrally (ie, placed directly into the urethra). Use one or two 7-mL tubes of Teflon paste. Because Teflon is an extremely dense material, use a high-pressure injector to implant the dense paste into the periurethral tissues.

• Periurethral route: Dispense the Teflon paste into the special high-pressure syringe connected to a 17-gauge needle. Slowly insert the needle next to the urethral opening and into the submucosal tissues. After ascertaining the proper position of the needle, inject the paste at 3 places around the urethra: the 2-, 6-, and 10-o'clock positions. As the injection progresses, the urethral lumen can be observed closing, and then the opening disappears. To assure success, visualize complete apposition (ie, kissing) of the urethral mucosa at the end of the procedure. One or 2 tubes may be injected to produce complete closure of the urethra.
• Transurethral route: Using a special high-pressure syringe, inject Teflon paste under direct vision underneath the urethral mucosa. Insert the cystoscope into the mid urethra. Under cystoscopic vision, insert the tip of the needle precisely underneath the urethral mucosa. Carefully inject the Teflon paste into the submucosal tissues until complete coaptation of the urethral mucosa is visualized.

Autologous fat injection

Completely anesthetize the patient and place in the lithotomy position. Prepare and drape the suprapubic and vaginal areas in a sterile fashion.

Initially, make a small surgical opening into the suprapubic area, and insert the end of a large-bore hollow probe (ie, 7-10 mm) that is connected to a high-pressure suction device. Using a liposuction technique, carefully extract 20-30 mL of fatty tissue from the lower abdomen. Meticulously transfer the harvested fatty tissue to several syringes for urethral injection.

Perform the entire procedure under direct vision using a cystoscope. Inject the fat periurethrally (ie, next to the urethra) or transurethrally (ie, directly into the urethra). Because the fat is low density, injections do not require a high-pressure injector.

• Periurethral route: Connect the syringe containing the autologous fat to an 18-gauge needle. Slowly insert the needle next to the urethral opening and into the submucosal tissues. After ascertaining the proper position of the needle in the proximal half of the urethra, carefully inject the fatty tissue at 3 places around the urethra: the 2-, 6-, and 10-o'clock positions. The lumen is visualized closing as the injection progresses. To assure success, observe complete apposition (closure) of the urethral mucosa at the end of the procedure. Complete urethral closure may require injecting 1-2 tubes.
• Transurethral route: Insert the cystoscope into the mid urethra. Under cystoscopic vision, connect the tip of the needle to a fat-filled syringe and gently slide it underneath the urethral mucosa. Slowly inject the fatty tissue into the submucosal tissues until complete coaptation of the urethral mucosa is visualized.

Collagen injection

Perform the procedure with the patient under local anesthesia in the office or in the operating room. Position the patient in the dorsal lithotomy position. Prepare and drape the vaginal area in a sterile fashion.

After careful preparation and draping, induce local anesthesia by gently instilling 2% lidocaine jelly directly into the urethra. Some surgeons provide additional anesthesia by injecting 1% lidocaine into the periurethral tissues next to the urethral opening. Insert the cystoscope into the urethra. Meticulously perform the entire procedure under direct vision using the cystoscope.

Inject the collagen in 1 of 2 ways, periurethrally or transurethrally. Although continence results are comparable using either approach, the transurethral route is generally preferred by the less experienced physician because more precise and efficient placement of collagen may result in a lower re-treatment rate and higher patient satisfaction. One or more (2.5-mL) syringes of collagen may be required.

• Periurethral route: Slowly insert a straight or "bent-needle" next to the urethral opening and into the submucosal tissues. After ascertaining the proper position of the needle in the proximal half of the urethra, slowly inject the paste at 3 places around the urethra: the 2-, 6-, and 10-o'clock positions. As the injection progresses, the urethral lumen is visualized closing. To assure success, complete apposition of the urethral mucosa must be observed at the end of the procedure. One or more syringes may be needed to produce complete closure.
• Transurethral route: Using a special needle, inject collagen paste under direct vision underneath the urethral mucosa. Insert the cystoscope into the mid urethra. Under cystoscopic vision, carefully insert the tip of the needle underneath the urethral mucosa. Precisely deposit the collagen paste into the submucosal tissues until complete coaptation of the urethral mucosa is visualized.
• Antegrade route: The antegrade route is reserved for males who are incontinent postprostatectomy. Create a suprapubic tract under adequate anesthesia. General anesthesia is preferred. Insert a flexible cystoscope into the bladder via the suprapubic tract. Identify the bladder neck. Under cystoscopic vision, carefully insert the tip of the needle underneath the bladder neck mucosa. Precisely deposit the collagen paste into the submucosal tissues until complete coaptation of the bladder neck is noted.

Carbon bead injection

The intraoperative protocol and the technique of injection are identical to Collagen injection. However, preoperative skin testing is not required.

Perform the procedure with the patient under local anesthesia in the office or in the operating room. Position the patient in the dorsal lithotomy position. Prepare and drape the vaginal area in a sterile fashion.

After careful preparation and draping, induce local anesthesia by gently instilling 2% lidocaine jelly directly into the urethra. Some surgeons provide additional anesthesia by injecting 1% lidocaine into the periurethral tissues next to the urethral opening. Insert the cystoscope into the urethra. Meticulously perform the entire procedure under direct vision using the cystoscope.

Inject the carbon bead particles in 1 of 2 ways, periurethrally or transurethrally. One or more (1.0-mL) syringes of Durasphere may be required.

• Periurethral route: Dispense carbon bead paste into a special syringe connected to an 18-gauge "bent-needle." Slowly insert the needle next to the urethral opening and into the submucosal tissues. After ascertaining the proper position of the needle in the proximal half of the urethra, slowly inject the paste at 3 places around the urethra: the 2-, 6-, and 10-o'clock positions. As the injection progresses, the urethral lumen is visualized closing. To assure success, complete apposition of the urethral mucosa must be observed at the end of the procedure. One or more syringes may be needed to produce complete closure.
• Transurethral route: Using a special needle, inject carbon bead paste under direct vision underneath the urethral mucosa. Insert the cystoscope into the mid urethra. Under cystoscopic vision, carefully insert the tip of the needle underneath the urethral mucosa. Precisely deposit the carbon bead paste into the submucosal tissues until complete coaptation of the urethral mucosa is visualized.

Postoperative details

Teflon paste injection

After the procedure, leave a Foley catheter indwelling for 24 hours and administer oral antibiotics for 3 days. This procedure results in minimal urethral pain that responds to simple analgesics. Do not perform repeat injections for 6 months.

Autologous fat injection

After the procedure, do not place a Foley catheter because it promotes molding of the urethra around the catheter. If molding occurs, the urethral lumen cannot properly close. Prescribe oral antibiotics for 3 days. This procedure results in minimal urethral pain that responds to simple analgesics.

Collagen injection

Patients notice immediate results after the injection. Perform a cough stress test immediately after the injection to assess for cure. If stress incontinence persists, immediately reinject additional collagen. If the patient remains dry, allow her to void prior to discharging home.

Do not place a Foley catheter routinely because it may cause molding of the urethra. If patients experience difficulty in urination, they may need to self-catheterize with a small (eg, 12F) catheter. Permanent urinary retention is rare. If repeat injection is necessary for delayed stress incontinence, reschedule for 4-6 weeks later.

Carbon bead injection

Postoperative care is identical to that of Collagen injection.

If antegrade injection has been performed, urethral catheter is unnecessary. Avoidance of a urethral catheter prevents molding of the bulking agent around the urethral catheter.

Follow-up

Postprocedural pain medications are rarely needed. Telephone the patient 24 hours after the injection therapy to inquire about possible urinary retention. If the patient is experiencing urinary retention, advise her to initiate the clean intermittent catheterization (CIC) protocol after nursing educational training. If the patient has a suprapubic tube for rare and complex cases, he/she may clamp and unclamp the suprapubic tube using a voiding schedule. The suprapubic tube is removed once the patient demonstrates a normal voiding pattern. Subsequent follow-up occurs at 3 months, 6 months, and annually thereafter.

COMPLICATIONS

Section 8 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Most women are able to void easily after the procedure; however, temporary urinary retention from urethral edema or urethral sphincter spasm is the most common complication of any injectable bulking procedure. Patients may treat urinary retention with self-catheterization using a small catheter (eg, 12F) until urethral edema disappears (within a few days).

Complications of Teflon paste

• Teflon is not approved for use (for female stress incontinence) in the United States because of concerns regarding local and distant migration of the Teflon particles into the lymph nodes, lung, and brain. However, Teflon has been used in Europe with no reported significant clinical complications. The complications discussed herein are based on studies of men postprostatectomy.
• Temporary urinary retention is the major postoperative problem (20-25%) after Teflon injection. Expect temporary urinary retention lasting 24-48 hours after the procedure. Permanent urinary retention is very rare, and intermittent self-catheterization may be initiated in selected cases. Irritative voiding symptoms have been reported in 20% of cases.
• Recurrent urinary incontinence may occur because of poor tissue coaptation or paste leaking into the urethral lumen. The inflammatory reaction and granuloma formation around the injected Teflon paste require several weeks to subside. If a second injection is needed, do not attempt until 3 months after the first procedure.
• Infection of the injection site and abscess formation lead to erosion of the urethral mucosa and result in infected fluid draining into the urethral lumen. This urethral ulceration heals spontaneously and does not lead to any permanent adverse sequelae.
• Routine use of Teflon injections in female patients has not been approved by the US FDA due to a theoretical health hazard; however, no human cases of death or carcinoma related to Teflon injections have been reported. Clinical trials show many active women with ISD have benefitted from the use of this biomaterial. Currently, the safety and efficacy of Teflon injections to treat incontinent women are being investigated in multicenter trials.

Complications of autologous fat

• Temporary urinary retention lasting 24-48 hours is expected after an injection. This is the major postoperative problem, occurring in 7% of women after fat injection. The patient can employ self-catheterization with a small catheter (eg, 12-14F) until it resolves.
• Permanent urinary retention has not been reported.
• Recurrent urinary incontinence occurs because of poor tissue coaptation or absorption of the fat by the host tissue.
• Lower abdominal pain at the site of liposuction has been reported (3%) but is only temporary.

Complications of collagen and carbon beads

• The most common complications are uncomplicated urinary tract infections, temporary urinary retention, and transient urethral irritation. Uncommon complications such as periurethral pseudocyst and urethrovaginal fistula also have been reported.
• Uncomplicated urinary tract infection occurs in 5% of cases.
• Temporary urinary retention has been reported in 15% of cases.
• Transient urethral irritation has been reported in 1% of cases.

OUTCOME AND PROGNOSIS

Section 9 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Teflon paste injection

No published reports exist regarding the safety and efficacy of Teflon injection to treat women with ISD. Multicenter clinical trials have been under way. For incontinent men, the success rate of Teflon injection is 75% with a follow-up of 6 months to 16 years.

Autologous fat injection

After fat injection, initial subjective improvement is reported to be as high as 83%; however, the cure rate declines to 57% after 1 year. Patients require 1-4 injections (average 2.5) to achieve continence. Information on the 2-year findings is rather limited.

Collagen injection

Available medical literature indicates that 67-96% of women with ISD remain dry 1 year after injection. After 2 years, 40-49% of incontinent women were cured, and 67-83% were either cured or improved. Reports indicate that collagen is a more effective bulking agent than fat. After 4 years, 27% remained cured and 36% remained improved.

The number of injections required to achieve continence varies from patient to patient. Kieswetter et al (1992) reported injecting 8.0 mL of Contigen at a single session. Corcos et al (1999) reported that the average number of injections in the first 6 months was 2.2, with an average volume of 9.0 mL of Contigen injected. Elsergany et al (1998) reported that, in their series, the average cumulative collagen injected per patient was 6.1 mL for the first 11 cases; whereas, in the last 22 cases, the average volume injected was 3.5 mL.

The efficacy of collagen injection in men who are incontinent postprostatectomy appears to be less compared to women. Tiguert et al (1999) performed transurethral collagen injection in 21 consecutive men with ISD. The mean total volume of collagen injected per patient was 18.4 mL (range, 1-44.5 mL), and the average number of injections was 2.9 (range, 1-5 injections). At a mean follow-up of 12.5 months, 1 (5%) patient became dry, 12 (57%) had significant improvement, and 8 (38%) had no change.

Silicone injection

Available literature reports that transurethral silicone injections were effective in 75% and 59% of incontinent patients at 6 and 12 months, respectively. For periurethral injection of silicone microimplants, the subjective cure rates were 80%, 72%, 65%, 60%, and 60% at 6 weeks, 3 months, 6 months, 1 year, and 3 years, respectively. Similar to autologous fat and collagen, a time-dependent decay in cure rates appears to exist.

Carbon bead injection

The FDA-approved carbon bead (Durasphere) injections in 1999 after they underwent a comparative randomized, multicenter, double-blinded study with collagen (Contigen). Carbon-bead injection compared to collagen injection showed similar outcomes, with Durasphere offering a slight benefit.

Antegrade injection using collagen

Early experience with this approach by Wainstein and Klutke (1997) has demonstrated an overall positive response rate of 70%; 70% of men who were incontinent postprostatectomy reported cure or significant improvement. However, in another study, Klutke et al (1999) have reported only a 10% cure and a 35% improved rate at mean follow-up of 28 months. Although antegrade delivery of collagen appears promising, this therapy fails a substantial number of patients at 2-year follow-up.

FUTURE AND CONTROVERSIES

Section 10 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

The initial introduction of injectable bulking agents has provided physicians with an additional option to treat stress urinary incontinence. The advent of newer agents with unique individualized merits and newer injectable techniques promises to dramatically alter the role of injectable bulking agents in the overall management of stress urinary incontinence. The selection of patients appears to be crucial but is not required for a successful outcome when this form of minimally invasive therapy is considered, especially in those who are less active and are at higher risk for complications inherent to more invasive procedures.

ACKNOWLEDGMENTS

Section 11 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author, Jong M. Choe, MD, FACS, to the development and writing of this article.

MULTIMEDIA

Section 12 of 13  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

Media file 1:  Periurethral injection therapy for incontinence. Figure A shows the needle advanced into the submucosa of the bladder neck. Figure B shows the bulking agent being injected into the submucosa of the bladder neck and proximal urethra.
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Media type:  Image

Media file 2:  Periurethral injection therapy for incontinence. This photograph shows lead pipe urethra associated with intrinsic sphincter deficiency (ISD). Note the bladder neck is wide open at rest before collagen injection.
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Media type:  Photo

Media file 3:  Periurethral injection therapy for incontinence. This photograph shows lead pipe urethra associated with intrinsic sphincter deficiency (ISD) after injection with periurethral collagen. Note the bladder neck is closed at rest.
	View Full Size Image
Media type:  Photo

REFERENCES

Section 13 of 13

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Acknowledgments
• Multimedia
• References

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• Tiguert R, Gheiler EL, Gudziak MR. Collagen injection in the management of post-radical prostatectomy intrinsic sphincteric deficiency. Neurourol Urodyn. 1999;18(6):653-8. [Medline].
• Wainstein MA, Klutke CG. Periurethral pseudocyst following cystoscopic collagen injection. Urology. May 1998;51(5):835-6. [Medline].
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Article Last Updated: Jun 29, 2006