Multichannel Urodynamics

The workup described constitutes the basic office assessment (BOA) of UI; it is generally accepted. However, the role of urodynamics in the evaluation of patients with UI is controversial. This is because the true impact of urodynamics on clinical diagnosis, management plans, and patient’s outcome has not been studied in a well-designed manner. As indicated by the Second International Consultation on Incontinence (ICI 2001): “In spite of the fundamental importance of urodynamics, the committee has found that for each type of test the evidence for ability or inability of urodynamic investigation to improve or at least predict the outcome of treatment of incontinence is based either on case series (level 4 evidence) or expert opinion (level 5 evidence),” ⁽¹⁾.

Nevertheless, they recommended urodynamic testing in the evaluation of UI under the following conditions:

• Prior to invasive treatments.
• After treatment failures.
• As part of a long-term surveillance program in neurogenic lower urinary tract dysfunction.
• In complicated incontinence.

Complicated incontinence includes recurrent incontinence and incontinence associated with the following: pain, hematuria, recurrent infection, voiding symptoms, pelvic irradiation, radical pelvic surgery, and suspected fistula.

The Agency for Health Care Policy and Research recommended considering surgery without referral for urodynamic testing for patients with symptoms of pure stress urinary loss and with a voiding history and physical examination results suggestive of pure hypermobility genuine stress incontinence (GSI), which includes the following ⁽²⁾:

1.  Urine loss occurs only with physical exertion (history and stress test).
2.  Voiding habits are normal (fewer than eight episodes per day and fewer than two episodes per night).
3.  There is no neurological history and no neurological findings.
4.  Patient has no history of antiincontinence or radical pelvic surgery.
5.  Pelvic examination documents hypermobility of the urethra and bladder neck, pliable and compliant vaginal wall, and adequate vaginal capacity.
6.  Postvoid residual volume is normal.
7.  Patient is not pregnant.

Weidner et al.  ⁽³⁾ reported that satisfying all Agency for Health Care Policy and Research criteria would predict GSI with high C statistics of 0.807; however, the findings applied to only 7.8% of the women seen in a tertiary care center. When Weber et al. ⁽⁴⁾ conducted a cost-effectiveness analysis of preoperative testing (BOA vs urodynamics) for SUI using a decision analysis model, they concluded that present findings suggest that, in adult women with SUI symptoms, urodynamic testing provides only a modest improvement in diagnostic accuracy compared to BOA.

The effectiveness of therapy was similar regardless of which type of preoperative evaluation was used. At a GSI prevalence of 0.79 or less, urodynamic testing outweighed the BOA because it is both less costly and more effective. However, at a GSI prevalence of 0.85 or above, the BOA outweighed urodynamic testing. Thus, in this model, cost-effectiveness was essentially related to the prevalence of GSI, which—at least in the Weidner et al.  report—was shown to be practice dependent.

The following procedures apply to selected patients with a history or physical findings suggestive of underlying urologic disease, prolapse, hematuria, recurrent infection, or recent history of an abdominal or pelvic procedure.

• Cystoscopy plays a limited role in the evaluation of patients with a straightforward, isolated SUI (level B evidence).  However, cystoscopy may be indicated in further evaluation when the following conditions are present: sterile hematuria or pyuria (level B recommendation); when urodynamics fails to duplicate symptoms (level C recommendation); and in new onset of irritative voiding symptoms, bladder pain, recurrent cystitis, or suspected foreign body (level B recommendation). Examination of the urethra may reveal a diverticulum, fistula, stricture, or urethritis. The bladder is inspected for mucosal or trigonal abnormalities,  trabeculation,  foreign bodies,  and stones.  Bladder-neck hypermobility and intrinsic sphincteric deficiency may also be reassessed by having the patient cough or strain with the scope in the midurethra.
• Urinary tract imaging plays a limited role in the evaluation of the uncomplicated case of female incontinence. Intravenous pyelography, voiding cystourethrography (VCUG), and ultrasound studies are commonly employed for evaluation of the upper and lower urinary tract, but in the assessment of UI, these are never first-line studies.
• Intravenous pyelography is indicated if the patient’s history suggests the presence of an ectopic ureter, hematuria, or recurrent urinary tract infections, and if hydroureteronephrosis is found during ultrasound or computed tomography studies.
• Ultrasonography is useful for the evaluation of the upper urinary tract, particularly to detect hydronephrosis caused by elevated bladder pressure in patients with neurogenic bladder-sphincteric dysfunction. In addition to the analysis of pelvic pathology, ultrasound has been used to determine a postvoid residual volume and to detect urethral diverticulum.
• VCUG is a simple, safe, and reliable examination that determines the integrity of the female lower urinary tract when bladder or urethral pathology is suspected, such as vesicovaginal or urethrovaginal fistulas, urethral diverticulum, or bladder prolapse. Now, although urethral hypermobility may be detected on rest and strain views, the VCUG is of limited reliability in providing conclusive evidence of intrinsic sphincteric deficiency because bladder pressure is not recorded during the examination.

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Adonis Hijaz, MD and Firouz Daneshgari, MD
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REFERENCES

1. Abrams P, Cardozo L, Khoury S, Wein A, eds. Incontinence. Second International Consultation on Incontinence, 2nd ed., Plymbridge Distributors, Plymouth, UK, 2002.
2. Agency for Health Care Policy and Research. Urinary Incontinence Clinical Practice Guidelines, US Department of Health and Human Services, Agency for Health Care Policy and Research, Washington, DC, 1996.
3. Weidner AC, Myers ER, Visco AG, Cundiff GW, Bump RC. Which women with stress incontinence require urodynamic evaluation? Am J Obstet Gynecol 2001;184:20-26.
4. Weber AM, Taylor RJ, Wei JT, Lemack G, Piedmonte MR, Walters MD. The cost-effectiveness of preoperative testing (basic office assessment vs urodynamics)  for stress urinary incontinence in women. BJU Int 2002;89:356-363.