Urinary Incontinence Case File

Urinary Incontinence Case File

Eugene C. Toy, MD, Patti Jayne Ross, MD, Benton Baker III, MD, John C. Jennings, MD

CASE 35

A 48-year-old G3P3 woman complains of a 2-year history of loss of urine four to five times each day, typically occurring with coughing, sneezing, or lifting; she denies dysuria or the urge to void during these episodes. These events cause her embarrassment and interfere with her daily activities. The patient is otherwise in good health. A urine culture performed 1 month previously was negative. On examination, she is slightly obese. Her blood pressure is 130/80 mm Hg, her heart rate is 80 beats per minute, and her temperature is 99°F (37.2°C). The breast examination is normal without masses. Her heart has a regular rate and rhythm without murmurs. The abdominal examination reveals no masses or tenderness. A midstream voided urinalysis is unremarkable.

» What is the most likely diagnosis?

» What physical examination finding is most likely to be present?

» What is the best initial treatment?

ANSWER TO CASE 35:

Urinary Incontinence                                          

Summary: A 48-year-old multiparous woman complains of urinary incontinence, which is related to stress activities. There is no urge component, and no delay from the Valsalva maneuver to the loss of urine.

• Most likely diagnosis: Genuine stress incontinence.
• Physical examination finding: Hypermobile urethra, cystocele, loss of urethrovesical angle, or positive cough stress test.
• Best initial treatment: Lifestyle modifications, Kegel exercises, and bladder training.

ANALYSIS

Objectives

1. Discern between the typical history of genuine stress urinary incontinence (GSUI) versus urge urinary incontinence (UUI).
2. Know that the cystometric examination can be used to distinguish between the two etiologies.
3. Know the treatments for both entities (GSUI and UUI).

Considerations

This patient’s history is very typical for genuine stress incontinence. She has loss of urine concurrent with coughing, sneezing, or lifting. There is no urge component or a delay from cough, as these findings would be consistent with urge incontinence. There is no evidence of diabetes or a neuropathy, making overflow incontinence unlikely. The pelvic examination likely reveals a cystocele (bladder bulging into the anterior vagina) or a loss of the normal bladder– urethral angle (hypermobile urethra); both of these findings of pelvic relaxation may be associated with the anatomic problem of GSUI, the bladder neck being below the abdominal cavity. In patients with urge incontinence, or mixed symptoms (loss of urine with Valsalva and urge to void), cystometric examination can be helpful to differentiate between genuine stress and urge incontinence. An accurate diagnosis is important, since the therapies for these two conditions are very different, and surgical therapy may actually worsen urge incontinence.

With genuine stress urinary incontinence, initial treatment usually entails pelvic floor strengthening exercises, called Kegel exercises. If these are unsuccessful, then options for treatment include pessaries or surgical management. Pessaries support the pelvic structures, and some compress the urethra. Surgical management focuses on restoring urethral support through various methods (suburethral slings, retropubic colposuspension). Suburethral slings include bladder neck slings and midurethral slings. A bladder neck sling is placed at the level of the proximal urethra and bladder. A midurethral sling is placed at the level of the midurethra. Retropubic colposuspension (Burch procedure) involves suspending the vaginal wall adjacent to the proximal urethra and bladder neck to a ligament (Cooper’s ligament) next to the pubic bone. Today, the midurethral sling procedures are the most popular methods to address this issue.

If a patient is a poor surgical candidate and does not desire pessary management, then urethral bulking agents that aim to approximate urethral mucosa may be used. This is generally used in patients with low leak point pressure.

APPROACH TO:

Urinary Incontinence                                             

DEFINITIONS

URINARY INCONTINENCE: The involuntary loss of urine that is objectively demonstrable and creates social or hygienic concern.

GENUINE STRESS INCONTINENCE: Incontinence through the urethra due to sudden increase in intra-abdominal pressure, in the absence of bladder muscle spasm. See Table 35– 1.

URGE INCONTINENCE: Loss of urine due to an uninhibited and sudden bladder detrusor muscle contraction.

OVERFLOW INCONTINENCE: Loss of urine associated with an overdistended, hypotonic bladder in the absence of detrusor contractions. This is often associated with diabetes mellitus, spinal cord injuries, or lower motor neuropathies. It may also be caused by urethral edema after pelvic surgery.

CYSTOMETRIC EVALUATION (URODYNAMICS): Investigation of pressure and volume changes in the bladder with the filling of known volumes. It is often used to discern between GSUI and UUI.

PESSARY: A device that is inserted into the vagina to treat pelvic support problems and urinary incontinence. Pessaries support the pelvic structures, and some compress the urethra. They come in all shapes and sizes. They are useful for women who do not want or cannot have surgery to correct their incontinence.

MIDURETHRAL SLING PROCEDURES: Procedure that relieves the symptoms of GSUI by supporting the mid urethra with a hammock-like effect, with procedures such as tension-free vaginal tape (TVT), or transobturator tape (TOT).

TRANSVAGINAL TAPE PROCEDURE: A minimally invasive procedure used to fix the midurethra through the retropubic space via a blind technique using a special hook-like instrument to place a synthetic tape under the urethra, which is the most commonly used procedure for stress incontinence.

TRANSOBTURATOR TAPE (TOT) PROCEDURE: A minimally invasive procedure similar to the TVT but originating laterally to try to avoid the bladder or bowel injuries that have been reported with the TVT procedures. The Trial of Midurethral Slings (TOMUS) study found that both procedures were comparable, but with TVTs having a slightly higher efficacy at the cost of greater rates of bladder perforation, bowel injury, and postoperative voiding dysfunction.

LEAK POINT PRESSURE: The intravesical pressure at which urine leakage occurs due to increased abdominal pressure (Valsalva or cough) in the absence of a detrusor contraction.

CLINICAL APPROACH

Normal Physiology

Urinary continence is maintained when the urethral pressure exceeds the intravesicular (bladder) pressure. The bladder and proximal urethra are normally intraabdominal in position, that is, above the pelvic diaphragm. In this situation, a Valsalva maneuver transmits pressure to both the bladder and proximal urethra so that continence is maintained. In the normal anatomic situation, the urethral pressure exceeds the bladder pressure, and also the pelvic diaphragm supports the bladder and urethra.

Mechanisms of Incontinence

Genuine Stress Incontinence: Following trauma and/ or other causes of weakness of the pelvic diaphragm (such as childbearing), the proximal urethra may fall below the pelvic diaphragm. When the patient coughs, intra-abdominal pressure is exerted to the bladder, but not to the proximal urethra. When the bladder pressure equals or exceeds the maximal urethral pressure, urinary flow occurs. Because this is a mechanical problem, the patient feels no urge to void, and the loss of urine occurs simultaneously with coughing. There is no delay from cough to incontinence. Urethropexy replaces the proximal urethra and urethrovesical junction back to its intra-abdominal position (Figure 35– 1). More recently, narrow strips

Figure 35–1. Bladder position: normal, genuine stress urinary incontinence, and after urethropexy. Normally, a Valsalva maneuver causes the increased intra-abdominal pressure (P) to be transmitted equally to the bladder and urethra (A). With genuine stress urinary incontinence, the proximal urethra has fallen outside the abdominal cavity (B) so that the intra-abdominal pressure no longer is transferred to the proximal urethra, leading to incontinence. After urethropexy (C), pressure is again transmitted to the urethra.

Figure 35–2. Placement of transobturator tape sling. Note that the hooked applicator instrument is used to pass through the obturator foramen, and then tension is adjusted. (Reproduced, with permission, from Schorge JO, Schaffer Ji, Halvorson LM, et al. Williams Gynecology. www.accessmedicine. com, Figures 42–4.3.)

of polypropylene mesh have been used to suspend the mid urethra due to the theory that urinary incontinence occurs due to pubourethral ligament insufficiency. These procedures act as a hammock to support the urethra, and also act to compress the urethra somewhat. These include various tension-free vaginal or obturator tape procedures, and outcomes are favorable as compared to urethropexy (Figure 35– 2). Because of the minimally invasive nature of these procedures and shorter operating times, they have gained popularity. Nevertheless, there is concern about erosion of the synthetic material into the bladder or vagina prompting an FDA warning in 2008, which was reaffirmed in 2011. Although the FDA excluded the bladder sling procedures, some patients have been reluctant to opt for the mesh slings. A large NIHfunded study was published in 2007, which demonstrated that the sling procedure using autologous fascia was superior to the Burch colposuspension to treat GSUI.

Urge Incontinence: With uninhibited spasms of the detrusor muscle, the bladder pressure overcomes the urethral pressure. Dysuria and/ or the urge to void are prominent symptoms, reflecting the bladder spasms. Sometimes, coughing or sneezing can provoke a bladder spasm, so that a delay of several seconds is noted before urine loss.

Overflow Incontinence: With an over distended bladder, coughing will increase the bladder pressure and eventually lead to dribbling or small loss of urine.

Work-Up

The history, physical examination, urinalysis, and postvoid residual are part of the initial evaluation of urinary incontinence. Lifestyle modifications, bladder training (including timed voiding), and pelvic musculature strengthening, seem to have a role and generally should be the first line of treatment. Lifestyle modifications include weight loss, dietary changes (less caffeine/ alcohol), avoiding constipation, and smoking cessation.

CASE CORRELATION See also Case 33 (Pelvic Organ Prolapse) since a cystocele is often associated with genuine stress urinary incontinence.

Note: A combined stress and mixed incontinence is probably the most common type of incontinence encountered; these patients will have symptoms of both stress and urge.

COMPREHENSION QUESTIONS

35.1 A 55-year-old woman notes constant wetness from her vagina following a total vaginal hysterectomy procedure, which she had undergone 2 months previously. She denies dysuria or urgency to void. The urine analysis is normal. Which of the following is the best method to diagnose the etiology of urinary incontinence?

A. Cystometric examination

B. Dye instillation into bladder

C. Postvoid catheterization of the bladder

D. Neurological profile of the sacral nerves

Match the following single best therapy (A-G) that will most likely help in the clinical situation described (35.2-35.4):

A. Suburethral sling procedure (with or without preceding Pessary trial)

B. Oxybutynin (Ditropan, an anticholinergic medication)

C. Placement of ureteral stents

D. Surgical repair of the fistulous tract

E. Propranolol (Inderal)

F. Placement of an artificial urethral sphincter

G. Intermittent self-catheterization

35.2 A 42-year-old woman with long-standing diabetes mellitus complains of small amounts of constant dribbling of urine loss with coughing or lifting.

35.3 A 39-year-old woman wets her underpants two to three times each day. She feels as though she needs to void, but cannot make it to the restroom in time.

35.4 A 35-year-old woman has undergone four vaginal deliveries. She notes urinary loss six to seven times a day concurrently with coughing or sneezing. She denies dysuria or an urge to void. Her urine culture is negative.

35.5 A 43-year-old woman has undergone a TVT procedure for genuine stress incontinence approximately 4 hours previously. She tolerated the procedure well. Postoperatively, the patient is noted to be voiding but “feels like the bladder is still full.” A postvoid residual is performed with 400 cc found in the bladder. Which of the following is the best management of this patient?

A. Discharge the patient home

B. Immediate surgery to remove the TVT sling

C. Perform a second voiding trial. Place a Foley catheter and discharge the patient with catheter if second voiding trial fails.

D. Order CT imaging to assess for hematoma or bowel injury

35.6 A 69-year-old woman is brought into your office with urinary incontinence. She has severe coronary artery disease, COPD, and renal insufficiency. On examination, she has a large cystocele and moderate uterine prolapse. What is the best treatment for this patient?

A. Artificial sphincter

B. Intermittent self-catherization

C. Midurethral sling procedure

D. Oxybutinin

E. Pessary device

ANSWERS

35.1 B. This patient likely has a vesicovaginal (between bladder and vagina) fistula from the surgery. A dye instilled into the bladder would be seen leaking into the vagina. If the leakage is slow, sometimes a tampon is placed into the vagina and removed after 30 to 60 minutes. Constant wetness after a pelvic operation suggests a fistula, such as vesicovaginal fistula, which is best treated with surgical repair, since it is an anatomic problem. Medications would not be helpful in this situation. The operation would include excision of the fistulous tract which usually may be infected or weakened, and then closure of the opening. Other common fistulae that may occur after pelvic surgery include ureterovaginal (between ureter and vagina) and rectovaginal fistulas (between rectum and vagina).

35.2 G. This patient has long-standing diabetes mellitus, which is a risk factor for a neurogenic bladder, leading to overflow incontinence. Other causes include spinal cord injury or multiple sclerosis. These patients generally do not feel the urge to void and accumulate large amounts of urine in their bladders. The best therapy for overflow incontinence (neurogenic bladder) is intermittent self-catheterization. Neither surgery (indicated for fistula repair), nor Burch urethropexy (indicated for genuine stress incontinence) would be appropriate for this scenario because it is not an anatomic problem. The medications listed would also not be indicated for neurogenic bladder; however, Bethanechol is a commonly prescribed drug to help stimulate bladder contractions by selectively acting on muscarinic receptors in the bladder muscles in individuals with overflow incontinence.

35.3 B. This woman’s prominent urge component makes urge incontinence the most likely diagnosis, best treated with anticholinergic medications. Anticholinergics relax the overactive detrusor muscle. Surgery would not be indicated in this situation, and in fact, may worsen the situation by further damaging nerves and muscles of the bladder. An artificial urethral sphincter would not improve the patient’s symptoms because the problem has to do with the detrusor muscle, and not the urethral sphincter. The patient is not having a problem with overflow, so self-catheterization would not be helpful either.

35.4 A. This clinical presentation is consistent with GSUI and is best treated by a pessary or sling procedure. Pessaries have been shown to have a ~ 40% to 60% patient satisfaction rate. However, patients can choose to have surgery without trying a pessary. There is some evidence that vaginal deliveries may increase the incidence of GSUI due to trauma to the pelvic diaphragm. The

medications listed would not be indicated for this patient because her symptoms are due to a weakening of the pelvic diaphragm versus a problem with the bladder itself, or muscles of the bladder, as with urge incontinence. Unlike urge incontinence, the patient feels no urge to void, and there is no delay noted before urine loss after a cough or sneeze. A cystometric or urodynamic evaluation helps to differentiate between urge and genuine stress incontinence.

35.5 C. The patient should undergo a second voiding trial prior to discharge. If the voiding trial fails, the patient should be discharged with a urethral catheter in place. A normal post void residual is less than 100 cc or one-third of the instilled volume (if < 300 mL is instilled into bladder for voiding trial). This patient’s PVR of 400 cc is clearly abnormal. Bladder retention is a known outcome of suburethral sling procedures. This patient’s bladder retention is mild since she is able to void somewhat, and usually will improve with time. She should be seen in the office in several days. If the patient was unable to void at all, the sling could be too tight, and the patient could benefit from loosening the sling prior to hospital discharge.

35.6 E. A pessary device would be the best initial treatment in this patient who likely has genuine stress incontinence based on the uterine prolapse, and due to her numerous and significant medical complications. A ring pessary with a knob may be able to support the urethra and bladder and address the urinary incontinence.

    CLINICAL PEARLS    

» In a woman who presents with urinary incontinence, a urinary tract infection should be ruled out. A voiding diary should also be collected. » The definitive treatment of genuine stress incontinence is surgical, whereas the best treatment of urge incontinence is medical. » Midurethral sling procedures have emerged as the most commonly performed procedures to treat GSUI because they have been demonstrated to have at least equal efficacy, shorter hospitalizations, shorter surgeries, and less pain as compared to the Burch urethropexy. » The tension-free vaginal tape (TVT) procedure has the most long-term outcome data but has slightly increased risk of bleeding and bowel injury. » Because of the concern for mesh erosion, even though the FDA warning excluded concern about urethral sling procedures, some patients will opt for the traditional urethropexy. » Cystometric or urodynamic evaluation helps to differentiate genuine from urge incontinence. » A postvoid catheterization showing a large residual volume suggests overflow incontinence. » Loss of urine occurs when the intravesicular pressure equals (or exceeds) the sphincter pressure.

REFERENCES

Albo ME, Richter HE, Brubaker L. Burch colposuspension versus fascial sling to reduce urinary incontinence. N Engl J Med. 2007;356:2143-2155. 

American College of Obstetricians and Gynecologists. Evaluation of uncomplicated stress urinary incontinence in women before surgical treatment. In: ACOG Committee Opinion 603. Washington, DC; 2014. 

American College of Obstetricians and Gynecologists. Pelvic organ prolapse. ACOG Practice Bulletin 85. Washington, DC; 2007. 

American College of Obstetricians and Gynecologists. Urinary incontinence in women. In: ACOG Practice Bulletin 63. Washington, DC; 2005. (Reaffirmed in 2011.) 

Lentz GM. Urogynecology. In: Katz VL, Lentz GM, Lobo RA, Gersenson DM, eds. Comprehensive Gynecology. 5th ed. St. Louis, MO: Mosby-Year Book; 2007:537-568. 

Rahn, D.D. Urinary Incontinence. Williams Gynecology. New York: McGraw-Hill Medical;2008:620-621. 

Richter, HE. A trial of continence pessary vs behavioral therapy vs combined therapy for stress incontinence. Obstet Gynecol. 2010;115(3):609-617. 

Richter, HE. Retropubic versus transobturator midurethal slings for stress incontinence. N Engl J Med. 2010 Jun 3;362(22):2066-2076.

Tarnay CM, Bhatia NN. Genitourinary dysfunction, pelvic organ prolapse, urinary incontinence, and infections. In: Hacker NF, Gambone JC, Hobel CJ, eds. Essentials of Obstetrics and Gynecology. 5th ed. Philadelphia, PA: Saunders; 2009:276-289.

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