Urodynamic Testing Not Needed for Uncomplicated Incontinence

Yael Waknine

May 03, 2012

May 3, 2012 — Preoperative urodynamic testing (UT) does not provide additional benefit in women with uncomplicated, demonstrable stress urinary incontinence (SUI), according to a noninferiority study published online May 2 in the New England Journal of Medicine.

Researchers, led by Charles W. Nager, MD, from the University of California, San Diego, found that the addition of these uncomfortable and expensive procedures to an office evaluation did not improve patient outcomes at 1 year, nor did it affect decision-making and management.

"Although there are different and sometimes a combination of causes for female urinary incontinence...the results of this study argue against routine preoperative urodynamic testing in uncomplicated primary stress urinary incontinence," Ziya Kirkali, MD, from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), told Medscape Medical News. Dr. Kirkali was not involved with the study.

Largest Study of UT Before SUI Surgery

For the study, researchers recruited 630 women aged 21 years and older with a 3-month history of SUI; an SUI score on the Medical, Epidemiological, and Social Aspects of Aging questionnaire; a postvoiding residual volume of less than 150 mL; a negative urinalysis/urine culture; a clinical assessment of urethral mobility; and a positive result on a provocative stress test.

Women with complicated cases (eg, prolapse, prior surgery for incontinence, or a history of pelvic irradiation) were excluded from the study.

Participants were randomly assigned to undergo preoperative office evaluation alone or with UT. UT consisted of noninstrumented uroflowmetry with a full bladder, filling cystometry with Valsalva leak-point pressures, and a pressure-flow study.

Results showed that treatment success at 1 year was similar between groups (77.2% vs 76.9%), as defined by a 70% or greater decrease from baseline in Urogenital Distress Inventory scores and a Patient Global Impression of Improvement response of "very much better" or "much better." The 0.3–percentage point difference (95% confidence interval [CI], −7.5 to 6.9 percentage points) fell within the predetermined criteria for noninferiority, indicating there was no significant difference between preoperative strategies.

Findings remained similar after adjustment for minor baseline differences in duration of incontinence, incontinence severity, smoking status, prior nonsurgical treatments for UI, current use of hormone-replacement therapy, and urethral mobility revealed similar outcomes.

In addition, no significant differences were found for several secondary outcome measures, including incontinence severity, condition-specific and global quality-of-life measures, and patient satisfaction. The incidence of adverse events was likewise similar (evaluation only, 19.4% vs 21.3%).

Although women who had undergone UT were significantly less likely to receive a diagnosis of overactive bladder incontinence or suspected intrinsic sphincter deficiency and were significantly more likely to be given a diagnosis of voiding-phase dysfunction, the distribution of treatments remained the same.

A similar percentage of women received the retropubic midurethral sling (evaluation only, 64.6% vs 64.7%), transobdurator midurethral sling (28.1% vs 29.0%), minisling (1.4% vs 2.0%), traditional sling (4.9% vs 3.4%), retropubic urethropexy (0.7% vs 0%), and urethral-bulking injection (0.4% vs 1.0%).

In general, UT had no effect on decision-making and management. Twelve women (3.8%) received a transobdurator rather than retropubic midurethral sling, and the reverse decision was applied to 6 others (1.9%).

According to Dr. Kirkali, the major drawback of the study is that more than 90% of participating surgeons were fellowship-trained, potentially enhancing their astuteness in clinical evaluation.

Critics Defy Recommendations Against Routine UT

Although some professional organizations recommend routine presurgical UT for patients with SUI, the National Institute for Health and Clinical Excellence has advised against this practice in "women with a clearly defined clinical diagnosis of pure urinary incontinence." The recommendation has met with resistance by researchers claiming that this condition is diagnosed in only 5% of patients at a tertiary care center in the United Kingdom.

Dr. Kirkali explained that the percentage of patients with pure SUI varies by clinical setting; the condition may be less prevalent in tertiary care centers and other practices that address more complicated cases.

The authors concur, noting that their eligibility criteria "more broadly reflect the characteristics of women with stress incontinence who are seen in clinical practice."

Praising the strength of the study, Dr. Kirkali noted that it was undertaken by 53 different surgeons in 11 centers who make up the Urinary Incontinence Treatment Network. "These centers are all interested in managing patients with urinary incontinence, and they have proven that it is feasible, and these patients can be recruited successfully in such a trial," he said.

Dr. Kirkali emphasized, however, that the findings apply only to women with primary uncomplicated SUI; UT may still be helpful for diagnosing the cause of urinary incontinence and provide useful information in more complicated cases, such as those involving prior incontinence-related surgery, neurologic disease, or urge-predominant incontinence.

The study was funded by the NIDDK and the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The study authors have disclosed no relevant financial relationships. Dr. Kirkali is program director of clinical and translational research in urologic diseases at the NIDDK, National Institutes of Health.

NEJM. Published online May 2, 2012. Full text


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